使用DataGrid动态绑定DropDownList

简单的使用模板列绑定DropDownList，初学者想必都会了，但有时候，我们要做的就是在编辑的时候想让某一列定制为DropDownList，并且根据正常情况下显示的值自动变换DropDownList中所选的值，然后保存选择后的值到数据库或XML文件，其实要做到这样的功能并不难，只要我们学会使用DataGrid的DataGrid1_ItemDataBound事件就行了，跟我来做个例子。

        //检索数据库的函数
          public DataSet GetZcbd()
          {
            try
           {
            DataSet ds=new DataSet();   
            string searchString="select id,yy,bj from zc";
            da=new OleDbDataAdapter(searchString,conn);
            da.Fill(ds,"yy");    
             return ds;
           }
           catch
           {
            return null;    
           }  
          }

         //绑定DataGrid   
        private void BindGrid()
          {
           DataSet ds = new DataSet();
           ds = us.GetZcbd();
           if (ds!=null)
           {
            this.DataGrid1.DataSource = ds;
            this.DataGrid1.DataBind();
           }
           else
           {
            msg.Alert("加载数据错误！",Page);
           }
          }
       
        绑定好DataGrid以后，设定模板列，让其正常显示下为Label,并绑定为数据库中一ID值，在编辑状态下为DropDownList，并绑定为数据库中一Name值，我们现在要做的就是当我们选择编辑时根据Label的值自动从数据库中取出编号为ID值的姓名，并用DropDownList默认选中。(注释：为了方便大家学习，我给出一个简单代码的例子，供大家参考)

<asp:datagrid allowpaging="True" borderwidth="1px" bordercolor="#3366CC" autogeneratecolumns="False" id="DataGrid1" borderstyle="None" backcolor="White" datakeyfield="bdid" width="100%" cellpadding="4" runat="server"><!----><asp:templatecolumn headertext="标记"><asp:dropdownlist id="DDLBJ" runat="server"><asp:templatecolumn headertext="标记"><asp:templatecolumn headertext="标记">          private void DataGrid1_ItemDataBound(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
            {
             if (e.Item.ItemType == ListItemType.EditItem)
             {
                 DataRowView drv = (DataRowView)e.Item.DataItem;
              string current = drv["label1"].ToString();
              DropDownList ddl = (DropDownList)e.Item.FindControl("ddl");
              ddl.SelectedIndex = ddl.Items.IndexOf(ddl.Items.FindByValue(current));
             }
             if ((e.Item.ItemType == ListItemType.Item)||(e.Item.ItemType == ListItemType.AlternatingItem))</asp:templatecolumn></asp:templatecolumn></asp:dropdownlist></asp:templatecolumn><asp:datagrid allowpaging="True" borderwidth="1px" bordercolor="#3366CC" autogeneratecolumns="False" borderstyle="None" backcolor="White" datakeyfield="bdid" width="100%" cellpadding="4" runat="server"><asp:templatecolumn headertext="标记"><asp:dropdownlist runat="server"><asp:templatecolumn headertext="标记"><asp:templatecolumn headertext="标记">  
         {
              Label t = (System.Web.UI.WebControls.Label)e.Item.FindControl("label1");
              string current = this.BindDDL(int.Parse(t.Text));
              e.Item.Cells[1].Text = current;
             }
            }</asp:templatecolumn></asp:templatecolumn></asp:dropdownlist></asp:templatecolumn></asp:datagrid></asp:datagrid>

<asp:datagrid allowpaging="True" borderwidth="1px" bordercolor="#3366CC" autogeneratecolumns="False" borderstyle="None" backcolor="White" datakeyfield="bdid" width="100%" cellpadding="4" runat="server"></asp:datagrid><asp:templatecolumn headertext="标记"></asp:templatecolumn><asp:dropdownlist runat="server"></asp:dropdownlist><asp:templatecolumn headertext="标记"></asp:templatecolumn><asp:templatecolumn headertext="标记">            private string BindDDL(int ddd)
            {
             string sss = "";
             if (ddd==1)
             {
              sss="张三";
              return sss;
             }
             else
             {
                 sss="李四";
              return sss;
             }
            }
</asp:templatecolumn>

   注释：msg为一个类似WinForm的messagebox对话框，不必理会。可以使用label.Text代替