DropDownlList的SelectedValue

Question

我有一個在編輯部分有dropdownlist的gridview，我想在編輯時綁定來自數據庫的selectedvalue。在設計器部分沒有SelectedValue屬性，它給運行時錯誤。怎麼做什麼幫助？有沒有辦法從代碼隱藏中處理它？

<asp:TemplateField HeaderText="Company"> 
       <EditItemTemplate> 
        <asp:DropDownList ID="DDLCompany" runat="server" DataValueField="cname" DataTextField="cname" SelectedValue = '<%# Bind("cname") %>' > 
        </asp:DropDownList> 
       </EditItemTemplate> 
       <ItemTemplate> 
       <asp:Label ID="CompanyLabel" runat="server" Text='<%# Bind("cname") %>'></asp:Label> 
       </ItemTemplate> 
      </asp:TemplateField> 

---

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e) 
    { 
     if (e.Row.RowType == DataControlRowType.DataRow) 
     { 
      DropDownList DDLCompany = (DropDownList)e.Row.FindControl("DDLCompany"); 
      DropDownList DDLPrinter = (DropDownList)e.Row.FindControl("DDLPrinter"); 

      if (DDLCompany != null) 
      { 
       DDLCompany.DataSource = userobj.FetchCompanyList(); 
       DDLCompany.DataBind(); 
       DDLCompany.SelectedValue = GridView1.DataKeys[e.Row.RowIndex].Values[0].ToString();     
      } 

      if (DDLPrinter != null) 
      { 
       DDLPrinter.DataSource = userobj.FetchPrinterList(); 
       DDLPrinter.DataBind(); 
       DDLPrinter.SelectedValue = GridView1.DataKeys[e.Row.RowIndex].Values[0].ToString(); 
      } 
     } 
    } 

Answer 1

• 在代碼隱藏，你必須檢查 爲e.Row.RowType == DataControlRowType.DataRow & & e.Row.RowState == DataControlRowState.Edit RowDataBound在 之前找到您的 Dropdwonlist。 http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridviewrow.dataitem.aspx
• 在ASPX您可以設置以下方式 seletcedvalue： http://msdn.microsoft.com/en-us/library/ms178294.aspx