Variable.EvaluateAsExpression 属性

定义

命名空间:

Microsoft.SqlServer.Dts.Runtime

程序集:

Microsoft.SqlServer.ManagedDTS.dll

获取或设置一个布尔值，该值指示变量是否包含表达式。

public:
 property bool EvaluateAsExpression { bool get(); void set(bool value); };

[Microsoft.SqlServer.Dts.Runtime.Localization.LocalizablePropertyDescription(typeof(Microsoft.SqlServer.Dts.Runtime.Localized), "EvaluateAsExpressionDesc")]
public bool EvaluateAsExpression { get; set; }

[<Microsoft.SqlServer.Dts.Runtime.Localization.LocalizablePropertyDescription(typeof(Microsoft.SqlServer.Dts.Runtime.Localized), "EvaluateAsExpressionDesc")>]
member this.EvaluateAsExpression : bool with get, set

Public Property EvaluateAsExpression As Boolean

属性值

Boolean

如果变量包含表达式，则为 true;否则为 false。

属性

LocalizablePropertyDescriptionAttribute

示例

以下示例设置标志 EvaluateAsExpression 以显示变量包含表达式，然后可以使用该 Expression 属性。

static void Main(string[] args)  
    {  
        Package p = new Package();  
        p.Variables.Add("x", false, "", 1);  
        Variable v = p.Variables.Add("y", false, "", 1);  
        v.Expression = "@x + 10";  
        v.EvaluateAsExpression = true;  
        if (v.Value.ToString() == "11")  
            Console.WriteLine("Value was 11");  
        else  
            Console.WriteLine("Value was not 11");  
    }  

Shared  Sub Main(ByVal args() As String)  
        Dim p As Package =  New Package()   
        p.Variables.Add("x", False, "", 1)  
        Dim v As Variable =  p.Variables.Add("y",False,"",1)   
        v.Expression = "@x + 10"  
        v.EvaluateAsExpression = True  
        If v.Value.ToString() = "11" Then  
            Console.WriteLine("Value was 11")  
        Else   
            Console.WriteLine("Value was not 11")  
        End If  
End Sub  

示例输出：

值为 11

注解

表达式和变量可用于控制包的流。 有关详细信息，请参阅 将表达式添加到优先约束。