GridView和DropDownList 偶数行的DROPDOWNLIST不能绑定默认值

GridView和DropDownList 偶数行的DROPDOWNLIST不能绑定默认值，奇数行可以，代码如下
<%@ Page language="C#" %>
<%@ import namespace="System.Data" %><script runat="server">
  
  void AuthorsGridView_RowDataBound (Object sender, GridViewRowEventArgs e)
  {
    // Check for a row in edit mode.
    if(e.Row.RowState == DataControlRowState.Edit)
    {
      // Preselect the DropDownList control with the state value
      // for the current row.
      
      // Retrieve the underlying data item. In this example
      // the underlying data item is a DataRowView object. 
      DataRowView rowView = (DataRowView)e.Row.DataItem;
      
      // Retrieve the state value for the current row. 
      String state = rowView["state"].ToString();
      
      // Retrieve the DropDownList control from the current row. 
      DropDownList list = (DropDownList)e.Row.FindControl("StatesList");
      
      // Find the ListItem object in the DropDownList control with the 
      // state value and select the item.
      ListItem item = list.Items.FindByText(state);
      list.SelectedIndex = list.Items.IndexOf(item);
    }
  }
  
  void AuthorsGridView_RowUpdating(Object sender, GridViewUpdateEventArgs e)
  {
    // Retrieve the row being edited.
    GridViewRow row = AuthorsGridView.Rows[AuthorsGridView.EditIndex];
    
    // Retrieve the DropDownList control from the row.
    DropDownList list = (DropDownList)row.FindControl("StatesList");
    
    // Add the selected value of the DropDownList control to 
    // the NewValues collection. The NewValues collection is
    // passed to the data source control, which then updates the 
    // data source.
    e.NewValues["state"] = list.SelectedValue;
  }
  
</script><html>
  <body>
    <form runat="server">
        
      <h3>GridViewRow DataItem Example</h3>      <asp:gridview id="AuthorsGridView" 
        datasourceid="AuthorsSqlDataSource" 
        autogeneratecolumns="false"
        autogenerateeditbutton="true" 
        datakeynames="au_id"
        onrowdatabound="AuthorsGridView_RowDataBound"
        onrowupdating="AuthorsGridView_RowUpdating"   
        runat="server"> 
               
        <columns>
          <asp:boundfield datafield="au_lname"
            headertext="Last Name"/>
          <asp:boundfield datafield="au_fname"
            headertext="First Name"/>
          <asp:templatefield headertext="State">
            <itemtemplate>
              <%#Eval("state")%>
            </itemtemplate>
            <edititemtemplate>
              <asp:dropdownlist id="StatesList"
                datasourceid="StatesSqlDataSource"
                datatextfield="state"  
                runat="server"/>  
              <asp:sqldatasource id="StatesSqlDataSource"  
                selectcommand="SELECT Distinct [state] FROM [authors]"
                connectionstring="server=localhost;database=pubs;integrated security=SSPI"
                runat="server">
              </asp:sqldatasource>
            </edititemtemplate>            
          </asp:templatefield>
        </columns>
                              
      </asp:gridview>
            
      <!-- This example uses Microsoft SQL Server and connects -->
      <!-- to the Pubs sample database.                        -->
      <asp:sqldatasource id="AuthorsSqlDataSource"  
        selectcommand="SELECT [au_id], [au_lname], [au_fname], [state] FROM [authors]"
        updatecommand="UPDATE authors SET [au_lname]=@au_lname, [au_fname]=@au_fname, [state]=@state WHERE au_id=@au_id"
        connectionstring="server=localhost;database=pubs;integrated security=SSPI"
        runat="server">
      </asp:sqldatasource>
            
    </form>
  </body>
</html>

解决方案 »

  1.   

    protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (((DropDownList)e.Row.FindControl("ddl")) != null)
            {        
                DropDownList ddl = (DropDownList)e.Row.FindControl("ddl");
                  ddl.Items.Clear();
                ddl.Items.Add(new ListItem("", "1"));            ddl.SelectedValue = ((HiddenField)e.Row.FindControl("HD_ID")).Value;
            }
        } protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
          {
             GridView1.EditIndex = e.NewEditIndex;         
              //绑定数据
          }
    参考
      

  2.   

    就是楼上所说的。RowDataBound事件和FindControl函数
      

  3.   

    (DropDownList)e.Row.FindControl("ddl")
      

  4.   

    谢谢大家，各位给的方法，都有不妥之处，我上面的代码是从msdn上COPY的，问题的关键是，下面这句话：   if(e.Row.RowState == DataControlRowState.Edit)为什么，点第一行的"编辑"，这个这个判断为true,而你点第二行的"编辑",这个判断为false,第三行为真，第四行为假。
    我不知道原因出在什么地方？