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GridView.RowCancelingEdit 事件

  • 参考

定义

命名空间:
System.Web.UI.WebControls
程序集:
System.Web.dll

单击编辑模式中某一行的“取消”按钮以后，在该行退出编辑模式之前发生。

public event System.Web.UI.WebControls.GridViewCancelEditEventHandler RowCancelingEdit;

事件类型

GridViewCancelEditEventHandler

示例

以下示例演示如何在用户取消控件的GridView更新操作时使用 RowCancelingEdit 事件显示取消消息。


<%@ 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">

  void CustomersGridView_RowCancelingEdit(Object sender, GridViewCancelEditEventArgs e)
  {
    
    // Retrieve the row that raised the event from the Rows
    // collection of the GridView control.
    GridViewRow row = CustomersGridView.Rows[e.RowIndex];
    
    // The update operation was canceled. Display the 
    // primary key of the row. In this example, the primary
    // key is displayed in the second column of the GridView
    // control. To access the text of the column, use the Cells
    // collection of the row.
    Message.Text = "Update for item " + row.Cells[1].Text + " Canceled."; 
    
  }

  void CustomersGridView_RowEditing(Object sender, GridViewEditEventArgs e)
  {

    // The GridView control is entering edit mode. Clear the message label.
    Message.Text = "";

  }
  
  void CustomersGridView_RowUpdated(Object sender, GridViewUpdatedEventArgs e)
  {

    // The update operation was successful. Clear the message label.
    Message.Text = "";

  }
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView RowCancelingEdit Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView RowCancelingEdit Example</h3>
            
      <asp:label id="Message"
        forecolor="Red"
        runat="server"/>
                
      <br/>
      
      <!-- The GridView control automatically sets the columns     -->
      <!-- specified in the datakeynames attribute as read-only.   -->
      <!-- No input controls are rendered for these columns in     -->
      <!-- edit mode.                                              -->
      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSqlDataSource" 
        autogeneratecolumns="true"
        autogenerateeditbutton="true"
        allowpaging="true" 
        datakeynames="CustomerID"
        onrowcancelingedit="CustomersGridView_RowCancelingEdit"
        onrowediting="CustomersGridView_RowEditing" 
        onrowupdated="CustomersGridView_RowUpdated"    
        runat="server">
      </asp:gridview>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSqlDataSource"  
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        updatecommand="Update Customers SET CompanyName=@CompanyName, Address=@Address, City=@City, PostalCode=@PostalCode, Country=@Country WHERE (CustomerID = @CustomerID)"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
        runat="server">
      </asp:sqldatasource>
            
    </form>
  </body>
</html>

以下示例演示如何在以编程方式设置数据源时使用 RowCancelingEdit 事件取消更新操作。

<%@ Page Language="C#" %>
<%@ Import Namespace="System.Data" %>

<!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 Page_Load(object sender, EventArgs e)
  {
          
    if (!Page.IsPostBack)
    {
      // Create a new table.
      DataTable taskTable = new DataTable("TaskList");
      
      // Create the columns.
      taskTable.Columns.Add("Id", typeof(int));
      taskTable.Columns.Add("Description", typeof(string));
      taskTable.Columns.Add("IsComplete", typeof(bool) );

      //Add data to the new table.
      for (int i = 0; i < 20; i++)
      {
        DataRow tableRow = taskTable.NewRow();
        tableRow["Id"] = i;
        tableRow["Description"] = "Task " + i.ToString();
        tableRow["IsComplete"] = false;            
        taskTable.Rows.Add(tableRow);
      }

      //Persist the table in the Session object.
      Session["TaskTable"] = taskTable;

      //Bind data to the GridView control.
      BindData();
    }

  }

  protected void TaskGridView_PageIndexChanging(object sender, GridViewPageEventArgs e)
  {
    TaskGridView.PageIndex = e.NewPageIndex;
    //Bind data to the GridView control.
    BindData();
  }

  protected void TaskGridView_RowEditing(object sender, GridViewEditEventArgs e)
  {
    //Set the edit index.
    TaskGridView.EditIndex = e.NewEditIndex;
    //Bind data to the GridView control.
    BindData();
  }

  protected void TaskGridView_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
  {
    //Reset the edit index.
    TaskGridView.EditIndex = -1;
    //Bind data to the GridView control.
    BindData();
  }

  protected void TaskGridView_RowUpdating(object sender, GridViewUpdateEventArgs e)
  {    
    //Retrieve the table from the session object.
    DataTable dt = (DataTable)Session["TaskTable"];

    //Update the values.
    GridViewRow row = TaskGridView.Rows[e.RowIndex];
    dt.Rows[row.DataItemIndex]["Id"] = ((TextBox)(row.Cells[1].Controls[0])).Text;
    dt.Rows[row.DataItemIndex]["Description"] = ((TextBox)(row.Cells[2].Controls[0])).Text;
    dt.Rows[row.DataItemIndex]["IsComplete"] = ((CheckBox)(row.Cells[3].Controls[0])).Checked;

    //Reset the edit index.
    TaskGridView.EditIndex = -1;

    //Bind data to the GridView control.
    BindData();
  }

  private void BindData()
  {
    TaskGridView.DataSource = Session["TaskTable"];
    TaskGridView.DataBind();
  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>GridView example</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
      <asp:GridView ID="TaskGridView" runat="server" 
        AutoGenerateEditButton="True" 
        AllowPaging="true"
        OnRowEditing="TaskGridView_RowEditing"         
        OnRowCancelingEdit="TaskGridView_RowCancelingEdit" 
        OnRowUpdating="TaskGridView_RowUpdating"
        OnPageIndexChanging="TaskGridView_PageIndexChanging">
      </asp:GridView>
    
    </div>
    </form>
</body>
</html>

注解

单击 RowCancelingEdit 编辑模式下某行的“取消”按钮，但在该行退出编辑模式之前，将引发 该事件。 这使你可以提供执行自定义例程的事件处理方法，例如，每当发生此事件时，如果取消操作会使行处于意外状态，则停止取消操作。

对象 GridViewCancelEditEventArgs 将传递给事件处理方法，该方法使你能够确定当前行的索引并指示取消操作应停止。 若要停止取消操作，请将 对象的 属性GridViewCancelEditEventArgs设置为 Canceltrue。

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

产品 版本
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

另请参阅