通过

任务 2：创建 PolicyActivity 和 RuleSet

  • 项目

在任务 1：创建 ConditionedActivityGroup 活动中，您将一个 ConditionedActivityGroup 活动添加到一个工作流，该工作流运行它所包含的所有子活动，直到队列中不再留有任何优惠券。 优惠券被使用 ConditionedActivityGroup 中的 CodeActivity 移除。

在本任务中，您将添加单个 PolicyActivity 活动。 此 PolicyActivity 活动使用一个包含四条不同规则的 RuleSet，这些规则分别对应于四个优惠券类型中的每个类型。 当 ConditionedActivityGroup 活动枚举所有优惠券时，每一条规则都将得到计算。 如果规则的 Condition 计算结果为 true，则它将应用与该优惠券关联的逻辑。

创建 PolicyActivity

  1. 在 DiscountWorkflow 类中，创建一个名为 couponPolicy 的私有 PolicyActivity。

    this.couponPolicy = new System.Workflow.Activities.PolicyActivity();

  2. 在 DiscountWorkflow 类的 InitializeComponent 方法中，创建已在上一步中创建的 PolicyActivity 对象的实例。

    此操作跟在设置 CanModifyActivities 属性的那一行后面。

    System.Workflow.Activities.Rules.RuleSetReference rulesetreference1 =
    new System.Workflow.Activities.Rules.RuleSetReference();

  3. 在 InitializeComponent 方法中创建一个名为 rulesetreference1 的 RuleSetReference 局部变量，然后创建该对象的实例。

    this.conditionedActivityGroup1.Activities.Add(this.couponPolicy);

  4. 在 InitializeComponent 方法中，使用在 Activities 属性中定义的 Add 方法，将 couponPolicy 对象添加到 conditionedActivityGroup1 对象的 Activities 集合中。

    备注

    必须在添加 removeCoupon 对象之前添加 couponPolicy 对象。 将子活动添加到 ConditionedActivityGroup 的顺序决定了它们的运行顺序。

    // 
// couponPolicy
// 
this.couponPolicy.Name = "couponPolicy";
rulesetreference1.RuleSetName = "RuleSet1";
this.couponPolicy.RuleSetReference = rulesetreference1;

  5. 将 couponPolicy 对象的 Name 属性设置为值 "couponPolicy"。

  6. 将 rulesetreference1 对象的 RuleSetName 设置为值 "RuleSet1"。

    备注

    下一过程中将创建此 RuleSet。

  7. 将 couponPolicy 对象的 RuleSetReference 属性设置为等于 rulesetreference1。 这会将该 PolicyActivity 与包含用于处理优惠券的规则的 RuleSet 关联。

    this.couponPolicy.SetValue(
    System.Workflow.Activities.ConditionedActivityGroup.WhenConditionProperty
    , ruleconditionreference3);

  8. 调用在 couponPolicy 对象中定义的 SetValue 方法，并且将 WhenConditionProperty 类型和 ruleconditionreference3 对象作为参数传入。

    备注

    通过设置 PolicyActivity 活动的 WhenConditionProperty，可以保证在每次 ConditionedActivityGroup 活动枚举其子活动时，PolicyActivity 活动都会运行。 如果没有为 ConditionedActivityGroup 中的子活动指定 WhenConditionProperty 条件，则该子活动只运行一次。

创建优惠券规则集

  1. 在 DiscountWorkflow.rules 文件中，将一个名为 RuleDefinitions.RuleSets 的新元素添加到 RuleDefinitions 根元素。

  2. 将一个名为 RuleSet 的子元素添加到 RuleDefinitions.RuleSets 元素。

  3. 将一个名为 Name 的属性添加到在上一步中创建的 RuleSet 元素，并将值“RuleSet1”赋给该属性。

  4. 将一个名为 ChainingBehavior 的属性添加到在步骤 3 中创建的 RuleSet 元素，并将值“Full”赋给该属性。

  5. 将一个名为 Description 的属性添加到在步骤 3 中创建的 RuleSet 元素，并将值“Coupon RuleSet”赋给该属性。

  6. 将一个名为 RuleSet.Rules 的子元素添加到 RuleSet 元素。

    您的 DiscountWorkflow.rules 文件将类似于下面的代码。

    <RuleDefinitions xmlns="https://schemas.microsoft.com/winfx/2006/xaml/workflow">
    <RuleDefinitions.Conditions>
        <!-- Conditions hidden for this example for readability -->
    </RuleDefinitions.Conditions>
    <RuleDefinitions.RuleSets>
        <RuleSet Name="RuleSet1" ChainingBehavior="Full" Description="Coupon RuleSet">
            <RuleSet.Rules>
            </RuleSet.Rules>
        </RuleSet>
    </RuleDefinitions.RuleSets>
</RuleDefinitions>

创建 getFreeItems 规则

  • 将下面的 Rule 复制到在上一个过程中创建的 RuleSet.Rules 元素。

    <Rule Name="getFreeItem" ReevaluationBehavior="Always" Priority="0" Description="{p5:Null}" Active="True" xmlns:p5="https://schemas.microsoft.com/winfx/2006/xaml">
    <Rule.ThenActions>
        <RuleStatementAction>
            <RuleStatementAction.CodeDomStatement>
                <ns0:CodeAssignStatement LinePragma="{p5:Null}" xmlns:ns0="clr-namespace:System.CodeDom;Assembly=System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                    <ns0:CodeAssignStatement.Left>
                        <ns0:CodePropertyReferenceExpression PropertyName="Discount">
                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                <ns0:CodeThisReferenceExpression />
                            </ns0:CodePropertyReferenceExpression.TargetObject>
                        </ns0:CodePropertyReferenceExpression>
                    </ns0:CodeAssignStatement.Left>
                    <ns0:CodeAssignStatement.Right>
                        <ns0:CodeBinaryOperatorExpression Operator="Add">
                            <ns0:CodeBinaryOperatorExpression.Left>
                                <ns0:CodePropertyReferenceExpression PropertyName="Discount">
                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                        <ns0:CodeThisReferenceExpression />
                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                </ns0:CodePropertyReferenceExpression>
                            </ns0:CodeBinaryOperatorExpression.Left>
                            <ns0:CodeBinaryOperatorExpression.Right>
                                <ns0:CodeFieldReferenceExpression FieldName="price">
                                    <ns0:CodeFieldReferenceExpression.TargetObject>
                                        <ns0:CodeIndexerExpression>
                                            <ns0:CodeIndexerExpression.Indices>
                                                <ns0:CodePrimitiveExpression>
                                                    <ns0:CodePrimitiveExpression.Value>
                                                        <ns1:Int32 xmlns:ns1="clr-namespace:System;Assembly=mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">0</ns1:Int32>
                                                    </ns0:CodePrimitiveExpression.Value>
                                                </ns0:CodePrimitiveExpression>
                                            </ns0:CodeIndexerExpression.Indices>
                                            <ns0:CodeIndexerExpression.TargetObject>
                                                <ns0:CodePropertyReferenceExpression PropertyName="Items">
                                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                                        <ns0:CodeThisReferenceExpression />
                                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                                </ns0:CodePropertyReferenceExpression>
                                            </ns0:CodeIndexerExpression.TargetObject>
                                        </ns0:CodeIndexerExpression>
                                    </ns0:CodeFieldReferenceExpression.TargetObject>
                                </ns0:CodeFieldReferenceExpression>
                            </ns0:CodeBinaryOperatorExpression.Right>
                        </ns0:CodeBinaryOperatorExpression>
                    </ns0:CodeAssignStatement.Right>
                </ns0:CodeAssignStatement>
            </RuleStatementAction.CodeDomStatement>
        </RuleStatementAction>
    </Rule.ThenActions>
    <Rule.Condition>
        <RuleExpressionCondition Name="{p5:Null}">
            <RuleExpressionCondition.Expression>
                <ns0:CodeBinaryOperatorExpression Operator="BooleanAnd" xmlns:ns0="clr-namespace:System.CodeDom;Assembly=System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                    <ns0:CodeBinaryOperatorExpression.Left>
                        <ns0:CodeBinaryOperatorExpression Operator="ValueEquality">
                            <ns0:CodeBinaryOperatorExpression.Left>
                                <ns0:CodeFieldReferenceExpression FieldName="type">
                                    <ns0:CodeFieldReferenceExpression.TargetObject>
                                        <ns0:CodeMethodInvokeExpression>
                                            <ns0:CodeMethodInvokeExpression.Method>
                                                <ns0:CodeMethodReferenceExpression MethodName="Peek">
                                                    <ns0:CodeMethodReferenceExpression.TargetObject>
                                                        <ns0:CodePropertyReferenceExpression PropertyName="Coupons">
                                                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                                                <ns0:CodeThisReferenceExpression />
                                                            </ns0:CodePropertyReferenceExpression.TargetObject>
                                                        </ns0:CodePropertyReferenceExpression>
                                                    </ns0:CodeMethodReferenceExpression.TargetObject>
                                                </ns0:CodeMethodReferenceExpression>
                                            </ns0:CodeMethodInvokeExpression.Method>
                                        </ns0:CodeMethodInvokeExpression>
                                    </ns0:CodeFieldReferenceExpression.TargetObject>
                                </ns0:CodeFieldReferenceExpression>
                            </ns0:CodeBinaryOperatorExpression.Left>
                            <ns0:CodeBinaryOperatorExpression.Right>
                                <ns0:CodeFieldReferenceExpression FieldName="FreeItem">
                                    <ns0:CodeFieldReferenceExpression.TargetObject>
                                        <ns0:CodeTypeReferenceExpression Type="Microsoft.Samples.Workflow.Tutorials.RulesAndConditions.DiscountWorkflow+CouponType" />
                                    </ns0:CodeFieldReferenceExpression.TargetObject>
                                </ns0:CodeFieldReferenceExpression>
                            </ns0:CodeBinaryOperatorExpression.Right>
                        </ns0:CodeBinaryOperatorExpression>
                    </ns0:CodeBinaryOperatorExpression.Left>
                    <ns0:CodeBinaryOperatorExpression.Right>
                        <ns0:CodeBinaryOperatorExpression Operator="GreaterThanOrEqual">
                            <ns0:CodeBinaryOperatorExpression.Left>
                                <ns0:CodePropertyReferenceExpression PropertyName="Count">
                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                        <ns0:CodePropertyReferenceExpression PropertyName="Items">
                                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                                <ns0:CodeThisReferenceExpression />
                                            </ns0:CodePropertyReferenceExpression.TargetObject>
                                        </ns0:CodePropertyReferenceExpression>
                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                </ns0:CodePropertyReferenceExpression>
                            </ns0:CodeBinaryOperatorExpression.Left>
                            <ns0:CodeBinaryOperatorExpression.Right>
                                <ns0:CodePrimitiveExpression>
                                    <ns0:CodePrimitiveExpression.Value>
                                        <ns1:Int32 xmlns:ns1="clr-namespace:System;Assembly=mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">5</ns1:Int32>
                                    </ns0:CodePrimitiveExpression.Value>
                                </ns0:CodePrimitiveExpression>
                            </ns0:CodeBinaryOperatorExpression.Right>
                        </ns0:CodeBinaryOperatorExpression>
                    </ns0:CodeBinaryOperatorExpression.Right>
                </ns0:CodeBinaryOperatorExpression>
            </RuleExpressionCondition.Expression>
        </RuleExpressionCondition>
    </Rule.Condition>
</Rule>

创建 applyPercentageOffHighest 规则

  • 将下面的 Rule 复制到在上一个过程中创建的 RuleSet.Rules 元素。

    <Rule Name="applyPercentageOffHighest" ReevaluationBehavior="Always" Priority="0" Description="{p5:Null}" Active="True" xmlns:p5="https://schemas.microsoft.com/winfx/2006/xaml">
    <Rule.ThenActions>
        <RuleStatementAction>
            <RuleStatementAction.CodeDomStatement>
                <ns0:CodeAssignStatement LinePragma="{p5:Null}" xmlns:ns0="clr-namespace:System.CodeDom;Assembly=System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                    <ns0:CodeAssignStatement.Left>
                        <ns0:CodePropertyReferenceExpression PropertyName="Discount">
                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                <ns0:CodeThisReferenceExpression />
                            </ns0:CodePropertyReferenceExpression.TargetObject>
                        </ns0:CodePropertyReferenceExpression>
                    </ns0:CodeAssignStatement.Left>
                    <ns0:CodeAssignStatement.Right>
                        <ns0:CodeBinaryOperatorExpression Operator="Add">
                            <ns0:CodeBinaryOperatorExpression.Left>
                                <ns0:CodePropertyReferenceExpression PropertyName="Discount">
                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                        <ns0:CodeThisReferenceExpression />
                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                </ns0:CodePropertyReferenceExpression>
                            </ns0:CodeBinaryOperatorExpression.Left>
                            <ns0:CodeBinaryOperatorExpression.Right>
                                <ns0:CodeBinaryOperatorExpression Operator="Multiply">
                                    <ns0:CodeBinaryOperatorExpression.Left>
                                        <ns0:CodeFieldReferenceExpression FieldName="price">
                                            <ns0:CodeFieldReferenceExpression.TargetObject>
                                                <ns0:CodeIndexerExpression>
                                                    <ns0:CodeIndexerExpression.Indices>
                                                        <ns0:CodeBinaryOperatorExpression Operator="Subtract">
                                                            <ns0:CodeBinaryOperatorExpression.Left>
                                                                <ns0:CodePropertyReferenceExpression PropertyName="Count">
                                                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                                                        <ns0:CodePropertyReferenceExpression PropertyName="Items">
                                                                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                                                                <ns0:CodeThisReferenceExpression />
                                                                            </ns0:CodePropertyReferenceExpression.TargetObject>
                                                                        </ns0:CodePropertyReferenceExpression>
                                                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                                                </ns0:CodePropertyReferenceExpression>
                                                            </ns0:CodeBinaryOperatorExpression.Left>
                                                            <ns0:CodeBinaryOperatorExpression.Right>
                                                                <ns0:CodePrimitiveExpression>
                                                                    <ns0:CodePrimitiveExpression.Value>
                                                                        <ns1:Int32 xmlns:ns1="clr-namespace:System;Assembly=mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">1</ns1:Int32>
                                                                    </ns0:CodePrimitiveExpression.Value>
                                                                </ns0:CodePrimitiveExpression>
                                                            </ns0:CodeBinaryOperatorExpression.Right>
                                                        </ns0:CodeBinaryOperatorExpression>
                                                    </ns0:CodeIndexerExpression.Indices>
                                                    <ns0:CodeIndexerExpression.TargetObject>
                                                        <ns0:CodePropertyReferenceExpression PropertyName="Items">
                                                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                                                <ns0:CodeThisReferenceExpression />
                                                            </ns0:CodePropertyReferenceExpression.TargetObject>
                                                        </ns0:CodePropertyReferenceExpression>
                                                    </ns0:CodeIndexerExpression.TargetObject>
                                                </ns0:CodeIndexerExpression>
                                            </ns0:CodeFieldReferenceExpression.TargetObject>
                                        </ns0:CodeFieldReferenceExpression>
                                    </ns0:CodeBinaryOperatorExpression.Left>
                                    <ns0:CodeBinaryOperatorExpression.Right>
                                        <ns0:CodePrimitiveExpression>
                                            <ns0:CodePrimitiveExpression.Value>
                                                <ns1:Double xmlns:ns1="clr-namespace:System;Assembly=mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">0.1</ns1:Double>
                                            </ns0:CodePrimitiveExpression.Value>
                                        </ns0:CodePrimitiveExpression>
                                    </ns0:CodeBinaryOperatorExpression.Right>
                                </ns0:CodeBinaryOperatorExpression>
                            </ns0:CodeBinaryOperatorExpression.Right>
                        </ns0:CodeBinaryOperatorExpression>
                    </ns0:CodeAssignStatement.Right>
                </ns0:CodeAssignStatement>
            </RuleStatementAction.CodeDomStatement>
        </RuleStatementAction>
    </Rule.ThenActions>
    <Rule.Condition>
        <RuleExpressionCondition Name="{p5:Null}">
            <RuleExpressionCondition.Expression>
                <ns0:CodeBinaryOperatorExpression Operator="ValueEquality" xmlns:ns0="clr-namespace:System.CodeDom;Assembly=System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                    <ns0:CodeBinaryOperatorExpression.Left>
                        <ns0:CodeFieldReferenceExpression FieldName="type">
                            <ns0:CodeFieldReferenceExpression.TargetObject>
                                <ns0:CodeMethodInvokeExpression>
                                    <ns0:CodeMethodInvokeExpression.Method>
                                        <ns0:CodeMethodReferenceExpression MethodName="Peek">
                                            <ns0:CodeMethodReferenceExpression.TargetObject>
                                                <ns0:CodePropertyReferenceExpression PropertyName="Coupons">
                                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                                        <ns0:CodeThisReferenceExpression />
                                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                                </ns0:CodePropertyReferenceExpression>
                                            </ns0:CodeMethodReferenceExpression.TargetObject>
                                        </ns0:CodeMethodReferenceExpression>
                                    </ns0:CodeMethodInvokeExpression.Method>
                                </ns0:CodeMethodInvokeExpression>
                            </ns0:CodeFieldReferenceExpression.TargetObject>
                        </ns0:CodeFieldReferenceExpression>
                    </ns0:CodeBinaryOperatorExpression.Left>
                    <ns0:CodeBinaryOperatorExpression.Right>
                        <ns0:CodeFieldReferenceExpression FieldName="PercentageOffHighest">
                            <ns0:CodeFieldReferenceExpression.TargetObject>
                                <ns0:CodeTypeReferenceExpression Type="Microsoft.Samples.Workflow.Tutorials.RulesAndConditions.DiscountWorkflow+CouponType" />
                            </ns0:CodeFieldReferenceExpression.TargetObject>
                        </ns0:CodeFieldReferenceExpression>
                    </ns0:CodeBinaryOperatorExpression.Right>
                </ns0:CodeBinaryOperatorExpression>
            </RuleExpressionCondition.Expression>
        </RuleExpressionCondition>
    </Rule.Condition>
</Rule>

过程标题

  • 将下面的 Rule 复制到在上一个过程中创建的 RuleSet.Rules 元素。

    <Rule Name="applyPercentageOffLowest" ReevaluationBehavior="Always" Priority="0" Description="{p5:Null}" Active="True" xmlns:p5="https://schemas.microsoft.com/winfx/2006/xaml">
    <Rule.ThenActions>
        <RuleStatementAction>
            <RuleStatementAction.CodeDomStatement>
                <ns0:CodeAssignStatement LinePragma="{p5:Null}" xmlns:ns0="clr-namespace:System.CodeDom;Assembly=System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                    <ns0:CodeAssignStatement.Left>
                        <ns0:CodePropertyReferenceExpression PropertyName="Discount">
                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                <ns0:CodeThisReferenceExpression />
                            </ns0:CodePropertyReferenceExpression.TargetObject>
                        </ns0:CodePropertyReferenceExpression>
                    </ns0:CodeAssignStatement.Left>
                    <ns0:CodeAssignStatement.Right>
                        <ns0:CodeBinaryOperatorExpression Operator="Add">
                            <ns0:CodeBinaryOperatorExpression.Left>
                                <ns0:CodePropertyReferenceExpression PropertyName="Discount">
                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                        <ns0:CodeThisReferenceExpression />
                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                </ns0:CodePropertyReferenceExpression>
                            </ns0:CodeBinaryOperatorExpression.Left>
                            <ns0:CodeBinaryOperatorExpression.Right>
                                <ns0:CodeBinaryOperatorExpression Operator="Multiply">
                                    <ns0:CodeBinaryOperatorExpression.Left>
                                        <ns0:CodeFieldReferenceExpression FieldName="price">
                                            <ns0:CodeFieldReferenceExpression.TargetObject>
                                                <ns0:CodeIndexerExpression>
                                                    <ns0:CodeIndexerExpression.Indices>
                                                        <ns0:CodePrimitiveExpression>
                                                            <ns0:CodePrimitiveExpression.Value>
                                                                <ns1:Int32 xmlns:ns1="clr-namespace:System;Assembly=mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">0</ns1:Int32>
                                                            </ns0:CodePrimitiveExpression.Value>
                                                        </ns0:CodePrimitiveExpression>
                                                    </ns0:CodeIndexerExpression.Indices>
                                                    <ns0:CodeIndexerExpression.TargetObject>
                                                        <ns0:CodePropertyReferenceExpression PropertyName="Items">
                                                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                                                <ns0:CodeThisReferenceExpression />
                                                            </ns0:CodePropertyReferenceExpression.TargetObject>
                                                        </ns0:CodePropertyReferenceExpression>
                                                    </ns0:CodeIndexerExpression.TargetObject>
                                                </ns0:CodeIndexerExpression>
                                            </ns0:CodeFieldReferenceExpression.TargetObject>
                                        </ns0:CodeFieldReferenceExpression>
                                    </ns0:CodeBinaryOperatorExpression.Left>
                                    <ns0:CodeBinaryOperatorExpression.Right>
                                        <ns0:CodePrimitiveExpression>
                                            <ns0:CodePrimitiveExpression.Value>
                                                <ns1:Double xmlns:ns1="clr-namespace:System;Assembly=mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">0.15</ns1:Double>
                                            </ns0:CodePrimitiveExpression.Value>
                                        </ns0:CodePrimitiveExpression>
                                    </ns0:CodeBinaryOperatorExpression.Right>
                                </ns0:CodeBinaryOperatorExpression>
                            </ns0:CodeBinaryOperatorExpression.Right>
                        </ns0:CodeBinaryOperatorExpression>
                    </ns0:CodeAssignStatement.Right>
                </ns0:CodeAssignStatement>
            </RuleStatementAction.CodeDomStatement>
        </RuleStatementAction>
    </Rule.ThenActions>
    <Rule.Condition>
        <RuleExpressionCondition Name="{p5:Null}">
            <RuleExpressionCondition.Expression>
                <ns0:CodeBinaryOperatorExpression Operator="ValueEquality" xmlns:ns0="clr-namespace:System.CodeDom;Assembly=System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                    <ns0:CodeBinaryOperatorExpression.Left>
                        <ns0:CodeFieldReferenceExpression FieldName="type">
                            <ns0:CodeFieldReferenceExpression.TargetObject>
                                <ns0:CodeMethodInvokeExpression>
                                    <ns0:CodeMethodInvokeExpression.Method>
                                        <ns0:CodeMethodReferenceExpression MethodName="Peek">
                                            <ns0:CodeMethodReferenceExpression.TargetObject>
                                                <ns0:CodePropertyReferenceExpression PropertyName="Coupons">
                                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                                        <ns0:CodeThisReferenceExpression />
                                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                                </ns0:CodePropertyReferenceExpression>
                                            </ns0:CodeMethodReferenceExpression.TargetObject>
                                        </ns0:CodeMethodReferenceExpression>
                                    </ns0:CodeMethodInvokeExpression.Method>
                                </ns0:CodeMethodInvokeExpression>
                            </ns0:CodeFieldReferenceExpression.TargetObject>
                        </ns0:CodeFieldReferenceExpression>
                    </ns0:CodeBinaryOperatorExpression.Left>
                    <ns0:CodeBinaryOperatorExpression.Right>
                        <ns0:CodeFieldReferenceExpression FieldName="PercentageOffLowest">
                            <ns0:CodeFieldReferenceExpression.TargetObject>
                                <ns0:CodeTypeReferenceExpression Type="Microsoft.Samples.Workflow.Tutorials.RulesAndConditions.DiscountWorkflow+CouponType" />
                            </ns0:CodeFieldReferenceExpression.TargetObject>
                        </ns0:CodeFieldReferenceExpression>
                    </ns0:CodeBinaryOperatorExpression.Right>
                </ns0:CodeBinaryOperatorExpression>
            </RuleExpressionCondition.Expression>
        </RuleExpressionCondition>
    </Rule.Condition>
</Rule>

创建 applyPercentageOffLowest 规则

  • 将下面的 Rule 复制到在上一个过程中创建的 RuleSet.Rules 元素。

    <Rule Name="applyPercentageOffLowest" ReevaluationBehavior="Always" Priority="0" Description="{p5:Null}" Active="True" xmlns:p5="https://schemas.microsoft.com/winfx/2006/xaml">
    <Rule.ThenActions>
        <RuleStatementAction>
            <RuleStatementAction.CodeDomStatement>
                <ns0:CodeAssignStatement LinePragma="{p5:Null}" xmlns:ns0="clr-namespace:System.CodeDom;Assembly=System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                    <ns0:CodeAssignStatement.Left>
                        <ns0:CodePropertyReferenceExpression PropertyName="Discount">
                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                <ns0:CodeThisReferenceExpression />
                            </ns0:CodePropertyReferenceExpression.TargetObject>
                        </ns0:CodePropertyReferenceExpression>
                    </ns0:CodeAssignStatement.Left>
                    <ns0:CodeAssignStatement.Right>
                        <ns0:CodeBinaryOperatorExpression Operator="Add">
                            <ns0:CodeBinaryOperatorExpression.Left>
                                <ns0:CodePropertyReferenceExpression PropertyName="Discount">
                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                        <ns0:CodeThisReferenceExpression />
                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                </ns0:CodePropertyReferenceExpression>
                            </ns0:CodeBinaryOperatorExpression.Left>
                            <ns0:CodeBinaryOperatorExpression.Right>
                                <ns0:CodeBinaryOperatorExpression Operator="Multiply">
                                    <ns0:CodeBinaryOperatorExpression.Left>
                                        <ns0:CodeFieldReferenceExpression FieldName="price">
                                            <ns0:CodeFieldReferenceExpression.TargetObject>
                                                <ns0:CodeIndexerExpression>
                                                    <ns0:CodeIndexerExpression.Indices>
                                                        <ns0:CodePrimitiveExpression>
                                                            <ns0:CodePrimitiveExpression.Value>
                                                                <ns1:Int32 xmlns:ns1="clr-namespace:System;Assembly=mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">0</ns1:Int32>
                                                            </ns0:CodePrimitiveExpression.Value>
                                                        </ns0:CodePrimitiveExpression>
                                                    </ns0:CodeIndexerExpression.Indices>
                                                    <ns0:CodeIndexerExpression.TargetObject>
                                                        <ns0:CodePropertyReferenceExpression PropertyName="Items">
                                                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                                                <ns0:CodeThisReferenceExpression />
                                                            </ns0:CodePropertyReferenceExpression.TargetObject>
                                                        </ns0:CodePropertyReferenceExpression>
                                                    </ns0:CodeIndexerExpression.TargetObject>
                                                </ns0:CodeIndexerExpression>
                                            </ns0:CodeFieldReferenceExpression.TargetObject>
                                        </ns0:CodeFieldReferenceExpression>
                                    </ns0:CodeBinaryOperatorExpression.Left>
                                    <ns0:CodeBinaryOperatorExpression.Right>
                                        <ns0:CodePrimitiveExpression>
                                            <ns0:CodePrimitiveExpression.Value>
                                                <ns1:Double xmlns:ns1="clr-namespace:System;Assembly=mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">0.15</ns1:Double>
                                            </ns0:CodePrimitiveExpression.Value>
                                        </ns0:CodePrimitiveExpression>
                                    </ns0:CodeBinaryOperatorExpression.Right>
                                </ns0:CodeBinaryOperatorExpression>
                            </ns0:CodeBinaryOperatorExpression.Right>
                        </ns0:CodeBinaryOperatorExpression>
                    </ns0:CodeAssignStatement.Right>
                </ns0:CodeAssignStatement>
            </RuleStatementAction.CodeDomStatement>
        </RuleStatementAction>
    </Rule.ThenActions>
    <Rule.Condition>
        <RuleExpressionCondition Name="{p5:Null}">
            <RuleExpressionCondition.Expression>
                <ns0:CodeBinaryOperatorExpression Operator="ValueEquality" xmlns:ns0="clr-namespace:System.CodeDom;Assembly=System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                    <ns0:CodeBinaryOperatorExpression.Left>
                        <ns0:CodeFieldReferenceExpression FieldName="type">
                            <ns0:CodeFieldReferenceExpression.TargetObject>
                                <ns0:CodeMethodInvokeExpression>
                                    <ns0:CodeMethodInvokeExpression.Method>
                                        <ns0:CodeMethodReferenceExpression MethodName="Peek">
                                            <ns0:CodeMethodReferenceExpression.TargetObject>
                                                <ns0:CodePropertyReferenceExpression PropertyName="Coupons">
                                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                                        <ns0:CodeThisReferenceExpression />
                                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                                </ns0:CodePropertyReferenceExpression>
                                            </ns0:CodeMethodReferenceExpression.TargetObject>
                                        </ns0:CodeMethodReferenceExpression>
                                    </ns0:CodeMethodInvokeExpression.Method>
                                </ns0:CodeMethodInvokeExpression>
                            </ns0:CodeFieldReferenceExpression.TargetObject>
                        </ns0:CodeFieldReferenceExpression>
                    </ns0:CodeBinaryOperatorExpression.Left>
                    <ns0:CodeBinaryOperatorExpression.Right>
                        <ns0:CodeFieldReferenceExpression FieldName="PercentageOffLowest">
                            <ns0:CodeFieldReferenceExpression.TargetObject>
                                <ns0:CodeTypeReferenceExpression Type="Microsoft.Samples.Workflow.Tutorials.RulesAndConditions.DiscountWorkflow+CouponType" />
                            </ns0:CodeFieldReferenceExpression.TargetObject>
                        </ns0:CodeFieldReferenceExpression>
                    </ns0:CodeBinaryOperatorExpression.Right>
                </ns0:CodeBinaryOperatorExpression>
            </RuleExpressionCondition.Expression>
        </RuleExpressionCondition>
    </Rule.Condition>
</Rule>

创建 applyPercentageOffTotal 规则

  • 将下面的 Rule 复制到在上一个过程中创建的 RuleSet.Rules 元素。

    <Rule Name="applyPercentageOffTotal" ReevaluationBehavior="Always" Priority="0" Description="{p5:Null}" Active="True" xmlns:p5="https://schemas.microsoft.com/winfx/2006/xaml">
    <Rule.ThenActions>
        <RuleStatementAction>
            <RuleStatementAction.CodeDomStatement>
                <ns0:CodeAssignStatement LinePragma="{p5:Null}" xmlns:ns0="clr-namespace:System.CodeDom;Assembly=System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                    <ns0:CodeAssignStatement.Left>
                        <ns0:CodePropertyReferenceExpression PropertyName="Discount">
                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                <ns0:CodeThisReferenceExpression />
                            </ns0:CodePropertyReferenceExpression.TargetObject>
                        </ns0:CodePropertyReferenceExpression>
                    </ns0:CodeAssignStatement.Left>
                    <ns0:CodeAssignStatement.Right>
                        <ns0:CodeBinaryOperatorExpression Operator="Add">
                            <ns0:CodeBinaryOperatorExpression.Left>
                                <ns0:CodePropertyReferenceExpression PropertyName="Discount">
                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                        <ns0:CodeThisReferenceExpression />
                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                </ns0:CodePropertyReferenceExpression>
                            </ns0:CodeBinaryOperatorExpression.Left>
                            <ns0:CodeBinaryOperatorExpression.Right>
                                <ns0:CodeBinaryOperatorExpression Operator="Multiply">
                                    <ns0:CodeBinaryOperatorExpression.Left>
                                        <ns0:CodePropertyReferenceExpression PropertyName="SubTotal">
                                            <ns0:CodePropertyReferenceExpression.TargetObject>
                                                <ns0:CodeThisReferenceExpression />
                                            </ns0:CodePropertyReferenceExpression.TargetObject>
                                        </ns0:CodePropertyReferenceExpression>
                                    </ns0:CodeBinaryOperatorExpression.Left>
                                    <ns0:CodeBinaryOperatorExpression.Right>
                                        <ns0:CodePrimitiveExpression>
                                            <ns0:CodePrimitiveExpression.Value>
                                                <ns1:Double xmlns:ns1="clr-namespace:System;Assembly=mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">0.2</ns1:Double>
                                            </ns0:CodePrimitiveExpression.Value>
                                        </ns0:CodePrimitiveExpression>
                                    </ns0:CodeBinaryOperatorExpression.Right>
                                </ns0:CodeBinaryOperatorExpression>
                            </ns0:CodeBinaryOperatorExpression.Right>
                        </ns0:CodeBinaryOperatorExpression>
                    </ns0:CodeAssignStatement.Right>
                </ns0:CodeAssignStatement>
            </RuleStatementAction.CodeDomStatement>
        </RuleStatementAction>
    </Rule.ThenActions>
    <Rule.Condition>
        <RuleExpressionCondition Name="{p5:Null}">
            <RuleExpressionCondition.Expression>
                <ns0:CodeBinaryOperatorExpression Operator="ValueEquality" xmlns:ns0="clr-namespace:System.CodeDom;Assembly=System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
                    <ns0:CodeBinaryOperatorExpression.Left>
                        <ns0:CodeFieldReferenceExpression FieldName="type">
                            <ns0:CodeFieldReferenceExpression.TargetObject>
                                <ns0:CodeMethodInvokeExpression>
                                    <ns0:CodeMethodInvokeExpression.Method>
                                        <ns0:CodeMethodReferenceExpression MethodName="Peek">
                                            <ns0:CodeMethodReferenceExpression.TargetObject>
                                                <ns0:CodePropertyReferenceExpression PropertyName="Coupons">
                                                    <ns0:CodePropertyReferenceExpression.TargetObject>
                                                        <ns0:CodeThisReferenceExpression />
                                                    </ns0:CodePropertyReferenceExpression.TargetObject>
                                                </ns0:CodePropertyReferenceExpression>
                                            </ns0:CodeMethodReferenceExpression.TargetObject>
                                        </ns0:CodeMethodReferenceExpression>
                                    </ns0:CodeMethodInvokeExpression.Method>
                                </ns0:CodeMethodInvokeExpression>
                            </ns0:CodeFieldReferenceExpression.TargetObject>
                        </ns0:CodeFieldReferenceExpression>
                    </ns0:CodeBinaryOperatorExpression.Left>
                    <ns0:CodeBinaryOperatorExpression.Right>
                        <ns0:CodeFieldReferenceExpression FieldName="PercentageOffTotal">
                            <ns0:CodeFieldReferenceExpression.TargetObject>
                                <ns0:CodeTypeReferenceExpression Type="Microsoft.Samples.Workflow.Tutorials.RulesAndConditions.DiscountWorkflow+CouponType" />
                            </ns0:CodeFieldReferenceExpression.TargetObject>
                        </ns0:CodeFieldReferenceExpression>
                    </ns0:CodeBinaryOperatorExpression.Right>
                </ns0:CodeBinaryOperatorExpression>
            </RuleExpressionCondition.Expression>
        </RuleExpressionCondition>
    </Rule.Condition>
</Rule>

编译代码

有关编译代码的信息，请参见编译代码。

有关本教程的完成版本，请参见完整的规则和条件教程。

请参见

参考

ConditionedActivityGroup
UntilCondition
RuleConditionReference
ConditionName
Activities
WhenConditionProperty
SetValue

其他资源

IfElse With Rules
Rules and Conditions

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