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Expression 属性

Gets or sets the expression contained in a variable.

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 Expression As String
    Get
    Set
用法
Dim instance As Variable
Dim value As String

value = instance.Expression

instance.Expression = value

public string Expression { get; set; }

public:
property String^ Expression {
    String^ get ();
    void set (String^ value);
}

member Expression : string with get, set

function get Expression () : String
function set Expression (value : String)

属性值

类型：System. . :: . .String
A String that contains the expression.

注释

The Expression method returns the expression entered in the value property only when the EvaluateAsExpression property is set to true; otherwise, an empty string is returned if false.

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