ListView.ItemCommand 事件

参考

定义

命名空间:: System.Web.UI.WebControls

程序集:: System.Web.Extensions.dll

重要

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当单击 ListView 控件中的按钮时发生。

public:
 event EventHandler<System::Web::UI::WebControls::ListViewCommandEventArgs ^> ^ ItemCommand;

public event EventHandler<System.Web.UI.WebControls.ListViewCommandEventArgs> ItemCommand;

member this.ItemCommand : EventHandler<System.Web.UI.WebControls.ListViewCommandEventArgs>

Public Custom Event ItemCommand As EventHandler(Of ListViewCommandEventArgs)

事件类型

EventHandler<ListViewCommandEventArgs>

示例

以下示例演示如何创建 ItemCommand 事件处理程序。

<%@ Page language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
  protected void EmployeesListView_OnItemCommand(object sender, ListViewCommandEventArgs e)
  {
    if (String.Equals(e.CommandName, "AddToList"))
    {
      // Verify that the employee ID is not already in the list. If not, add the
      // employee to the list.
      ListViewDataItem dataItem = (ListViewDataItem)e.Item;
      string employeeID = 
        EmployeesListView.DataKeys[dataItem.DisplayIndex].Value.ToString();
      
      if (SelectedEmployeesListBox.Items.FindByValue(employeeID) == null)
      {
        ListItem item = new ListItem(e.CommandArgument.ToString(), employeeID);
        SelectedEmployeesListBox.Items.Add(item);
      }
    }
  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Employee List</title>
  </head>
  <body>
    <form id="form1" runat="server">
      <asp:ListView runat="server" 
        ID="EmployeesListView"
        OnItemCommand="EmployeesListView_OnItemCommand"
        DataSourceID="EmployeesDataSource" 
        DataKeyNames="EmployeeID">
        <LayoutTemplate>
          <table runat="server" id="tblEmployees" 
                 cellspacing="0" cellpadding="1" width="440px" border="1">
            <tr id="itemPlaceholder" runat="server"></tr>
          </table>
          <asp:DataPager ID="EmployeesDataPager" runat="server" PageSize="10">
            <Fields>
              <asp:NumericPagerField />
            </Fields>
          </asp:DataPager>
        </LayoutTemplate>
        <ItemTemplate>
          <tr runat="server">
            <td>
              <asp:Label runat="server" ID="NameLabel" 
                Text='<%#Eval("LastName") + ", " + Eval("FirstName") %>' />
            </td>
            <td style="width:80px">
              <asp:LinkButton runat="server" 
                ID="SelectEmployeeButton" 
                Text="Add To List" 
                CommandName="AddToList" 
                CommandArgument='<%#Eval("LastName") + ", " + Eval("FirstName") %>' />
            </td>
          </tr>
        </ItemTemplate>
      </asp:ListView>
      
      <br /><br />
      <b>Selected Employees:</b><br />
      <asp:ListBox runat="server" ID="SelectedEmployeesListBox" Rows="10" Width="300px" />
       
      <!-- This example uses Microsoft SQL Server and connects      -->
      <!-- to the AdventureWorks sample database. Use an ASP.NET    -->
      <!-- expression to retrieve the connection string value       -->
      <!-- from the Web.config file.                                -->       
      <asp:SqlDataSource ID="EmployeesDataSource" runat="server" 
        ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
        SelectCommand="SELECT [EmployeeID], [FirstName], [LastName]
                       FROM HumanResources.vEmployee
                       ORDER BY [LastName], [FirstName], [EmployeeID]">
      </asp:SqlDataSource>
    </form>
  </body>
</html>

<%@ Page language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
  Protected Sub EmployeesListView_OnItemCommand(ByVal sender As Object, _
  ByVal e As ListViewCommandEventArgs)
    
    If String.Equals(e.CommandName, "AddToList") Then
      
      ' Verify that the employee ID is not already in the list. If not, add the
      ' employee to the list.
      Dim dataItem As ListViewDataItem = CType(e.Item, ListViewDataItem)
      Dim employeeID As String = _
        EmployeesListView.DataKeys(dataItem.DisplayIndex).Value.ToString()
      
      If SelectedEmployeesListBox.Items.FindByValue(employeeID) Is Nothing Then
        Dim item As ListItem = _
          New ListItem(e.CommandArgument.ToString(), employeeID)
        SelectedEmployeesListBox.Items.Add(item)
      End If
      
    End If
    
  End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head2" runat="server">
    <title>Employee List</title>
  </head>
  <body>
    <form id="form1" runat="server">
      <asp:ListView runat="server" 
        ID="EmployeesListView"
        OnItemCommand="EmployeesListView_OnItemCommand"
        DataSourceID="EmployeesDataSource" 
        DataKeyNames="EmployeeID">
        <LayoutTemplate>
          <table runat="server" id="tblEmployees" 
                 cellspacing="0" cellpadding="1" width="440px" border="1">
            <tr id="itemPlaceholder" runat="server"></tr>
          </table>
          <asp:DataPager ID="EmployeesDataPager" runat="server" PageSize="10">
            <Fields>
              <asp:NumericPagerField />
            </Fields>
          </asp:DataPager>
        </LayoutTemplate>
        <ItemTemplate>
          <tr runat="server">
            <td>
              <asp:Label runat="server" ID="NameLabel" 
                Text='<%#Eval("LastName") & ", " & Eval("FirstName") %>' />
            </td>
            <td style="width:80px">
              <asp:LinkButton runat="server" 
                ID="SelectEmployeeButton" 
                Text="Add To List" 
                CommandName="AddToList" 
                CommandArgument='<%#Eval("LastName") & ", " & Eval("FirstName") %>' />
            </td>
          </tr>
        </ItemTemplate>
      </asp:ListView>
      
      <br /><br />
      <b>Selected Employees:</b><br />
      <asp:ListBox runat="server" ID="SelectedEmployeesListBox" Rows="10" Width="300px" />
       
      <!-- This example uses Microsoft SQL Server and connects      -->
      <!-- to the AdventureWorks sample database. Use an ASP.NET    -->
      <!-- expression to retrieve the connection string value       -->
      <!-- from the Web.config file.                                -->       
      <asp:SqlDataSource ID="EmployeesDataSource" runat="server" 
        ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
        SelectCommand="SELECT [EmployeeID], [FirstName], [LastName]
                       FROM HumanResources.vEmployee
                       ORDER BY [LastName], [FirstName], [EmployeeID]">
      </asp:SqlDataSource>
    </form>
  </body>
</html>

注解

单击 ItemCommand 控件中的按钮时， ListView 将引发该事件。这使你可以在发生此事件时执行自定义例程。

控件中的 ListView 按钮还可以调用控件的内置功能。下表列出了可用于 CommandName 按钮属性以调用内置功能的值。

CommandName 值	说明
“取消”	取消编辑或插入操作。引发 ItemCanceling 事件。
“Delete”	从数据源中删除当前记录。引发 ItemDeleted 和 ItemDeleting 事件。
“选择”	将 SelectedIndex 属性设置为 DisplayIndex 项的属性值。呈现 SelectedItemTemplate 项的模板。引发 SelectedIndexChanging 和 SelectedIndexChanged 事件。
“编辑”	将项目置于编辑模式。呈现 EditItemTemplate 项的模板。引发 ItemEditing 事件。
“Insert”	将模板中的 InsertItemTemplate 绑定值插入数据源。引发 ItemInserting 和 ItemInserted 事件。
“更新”	使用模板中的绑定值EditItemTemplate汇报数据源中的当前记录。引发 ItemUpdating 和 ItemUpdated 事件。
“Sort”	对按钮的属性中列出的 `CommandArgument` 列进行排序。引发 Sorting 和 Sorted 事件。

单击 ItemCommand 上表中列出的按钮时，也会引发该事件。但是，建议使用表中列出的事件。事件 ItemCommand 通常用于处理自定义操作。

对象 ListViewCommandEventArgs 将传递给事件处理程序，这使你可以确定所单击按钮的命令名称和命令参数。若要确定命令名称，请使用 CommandEventArgs.CommandName 属性。若要确定命令参数，请使用 CommandEventArgs.CommandArgument 属性。若要访问引发事件的控件，请使用 ListViewCommandEventArgs.CommandSource 属性。

有关如何处理事件的详细信息，请参阅处理和引发事件。

适用于

ListView.ItemCommand 事件

定义

事件类型

示例

注解

适用于

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