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EvaluateAsExpression 属性

Gets or sets a Boolean that indicates that the variable contains an expression.

命名空间：  Microsoft.SqlServer.Dts.Runtime
程序集：  Microsoft.SqlServer.ManagedDTS（在 Microsoft.SqlServer.ManagedDTS.dll 中）

语法

声明
Public Property EvaluateAsExpression As Boolean
    Get
    Set
用法
Dim instance As Variable
Dim value As Boolean

value = instance.EvaluateAsExpression

instance.EvaluateAsExpression = value

public bool EvaluateAsExpression { get; set; }

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

member EvaluateAsExpression : bool with get, set

function get EvaluateAsExpression () : boolean
function set EvaluateAsExpression (value : boolean)

属性值

类型：System. . :: . .Boolean
A Boolean that indicates if the variable contains an expression.

注释

Expressions and variables can be used to control the flow of a package. For more information, see 将表达式添加到优先约束.

示例

The following example sets the EvaluateAsExpression flag to show that the variable contains an expression, and then can use the Expression property.

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

Sample Output:

Value was 11