Question

asp.net gridview编辑时，下拉框选择上默认的选项

前台： <asp:TemplateField HeaderText="所属类名">
<ItemTemplate>
<asp:Label ID="Label3" runat="server" Text='<%#Eval("firName") %>' ></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList ID="dfirst" runat="server">
</asp:DropDownList>
</EditItemTemplate>
我想在点击修改后，这个下拉框默认选择的项是与数据库中的数值对应的，不知道该如何实现。我的后台代码：
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
if(e.Row.RowState == DataControlRowState.Edit ||e.Row.RowState == (DataControlRowState.Alternate | DataControlRowState.Edit))
{
path = "select firId,secId from video_Video where vId=" + GridView1.DataKeys[e.Row.RowIndex].Value.ToString() +"";

re = sqldo.GetRow(path);
if (re.Read())
{
int firID = Convert.ToInt16(re["firId"].ToString());
re.Close();
//一级类绑定
DropDownList list = (DropDownList)e.Row.FindControl("dfirst");
path = "select * from video_FirstClass";
list.DataSource = sqldo.GetRows(path, "a");
list.DataTextField = "firName";
list.DataValueField = "firId";
list.DataBind();
list.SelectedIndex = Convert.ToInt16(re["firId"].ToString());
sqlcon.SqlClose();
}

Answer 1

把list.SelectedIndex = Convert.ToInt16(re["firId"].ToString());
改成
if(!string.IsNullOrEmpty(re["firId"].ToString()))
{
list.SelectedValue = re["firId"].ToString();
}
判断一下值是否为空，为空可能会报错！

Answer 2

list.SelectedIndex = Convert.ToInt16(re["firId"].ToString());
改成
list.SelectedValue = re["firId"].ToString();

Answer 3

创建一个 RowUpdate时间
protected void GV_RowUpdating(object sender, GridViewUpdateEventArgs e)
{

}
最好还是在这里做啊！

Answer 4

不行找我
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
if(e.Row.RowState == DataControlRowState.Edit ||e.Row.RowState == (DataControlRowState.Alternate | DataControlRowState.Edit))
{
path = "select firId,secId from video_Video where vId=" + GridView1.DataKeys[e.Row.RowIndex].Value.ToString() +"";

re = sqldo.GetRow(path);
if (re.Read())
{
int firID = Convert.ToInt16(re["firId"].ToString());
re.Close();
//一级类绑定
DropDownList list = (DropDownList)e.Row.FindControl("dfirst");
path = "select * from video_FirstClass";
list.DataSource = sqldo.GetRows(path, "a");
list.DataTextField = "firName";
list.DataValueField = "firId";
list.DataBind();

list.SelectedValue = firID.ToString();
sqlcon.SqlClose();
}