ParameterCollection.RemoveAt(Int32) 方法

定义

命名空间:

System.Web.UI.WebControls

程序集:

System.Web.dll

移除 Parameter 集合中指定索引处的 ParameterCollection 对象。

public:
 void RemoveAt(int index);

public void RemoveAt (int index);

member this.RemoveAt : int -> unit

Public Sub RemoveAt (index As Integer)

参数

index

Int32

要移除的 Parameter 的索引。

示例

下面的代码示例演示如何使用 RemoveAt 方法从特定位置的ParameterCollection集合中删除Parameter对象。 在此示例中，将多个 QueryStringParameter 对象添加到集合 SelectParameters ，从集合中删除一个 QueryStringParameter 对象，并在页面加载时打印集合的顺序。

<%@page Language="C#" %>
<SCRIPT runat="server">
private void Page_Load(object sender, EventArgs e) {

    SqlDataSource aSqlDataSource = new SqlDataSource();

    // Security Note: The SqlDataSource uses a QueryStringParameter,
    // Security Note: which does not perform validation of input from the client.

    QueryStringParameter qs1 =
        new QueryStringParameter("QueryStringParam1","requestfield1");

    aSqlDataSource.SelectParameters.Add(qs1);

    QueryStringParameter qs3 =
        new QueryStringParameter("QueryStringParam2","requestfield2");

    aSqlDataSource.SelectParameters.Add(qs3);

    // Insert another QueryStringParameter with the same name as the previous parameter.
    aSqlDataSource.SelectParameters.Add( new QueryStringParameter("QueryStringParameter2","requestfield3") );

    // There are two parameters named QueryStringParam3. Use the
    // RemoveAt method to remove the last element from the collection.
    aSqlDataSource.SelectParameters.RemoveAt( (aSqlDataSource.SelectParameters.Count - 1) );

    // Iterate through the ParameterCollection and print out the
    // names of the Parameters contained by it.
    foreach (Parameter aParameter in aSqlDataSource.SelectParameters) {
        Response.Write(aParameter.Name + "<BR>");
        QueryStringParameter qsptemp = (QueryStringParameter) aParameter;
        Response.Write("QueryStringField is " + qsptemp.QueryStringField + "<BR>");
    }
}
</SCRIPT>

<%@page Language="VB" %>
<SCRIPT runat="server">
Sub Page_Load(sender As Object, e As EventArgs)

    Dim aSqlDataSource As New SqlDataSource()

    ' Security Note: The SqlDataSource uses a QueryStringParameter,
    ' Security Note: which does not perform validation of input from the client.

    Dim qs1 As New QueryStringParameter("QueryStringParam1","requestfield1")
    aSqlDataSource.SelectParameters.Add(qs1)

    Dim qs2 As New QueryStringParameter("QueryStringParam2","requestfield2")
    aSqlDataSource.SelectParameters.Add(qs2)

    ' Insert another QueryStringParameter with the same name as the previous parameter.
    Dim qs3 As New QueryStringParameter("QueryStringParam2","requestfield3")
    aSqlDataSource.SelectParameters.Add(qs3)

    ' There are two parameters named QueryStringParam3. Use the
    ' RemoveAt method to remove the last element from the collection.
    aSqlDataSource.SelectParameters.RemoveAt( (aSqlDataSource.SelectParameters.Count - 1) )

    ' Iterate through the ParameterCollection and print out the
    ' names of the Parameters contained by it.
    Dim aParameter As Parameter
    For Each aParameter in aSqlDataSource.SelectParameters
        Response.Write(aParameter.Name & "<BR>")
        Dim qsptemp As QueryStringParameter = CType(aParameter, QueryStringParameter)
        Response.Write("QueryStringField is " & qsptemp.QueryStringField & "<BR>")
    Next
End Sub ' Page_Load
</SCRIPT>

注解

RemoveAt使用 方法从集合中删除Parameter指定索引处的对象。

另请参阅

• Parameter
• Add(Parameter)
• RemoveAt(Int32)