将asp.net中的下拉列表绑定到项目模板的行绑定中
本文关键字:绑定 项目 下拉列表 asp net | 更新日期: 2023-09-27 18:03:22
我正在尝试绑定一个下拉菜单,这是在一个网格,但我得到错误。
<asp:GridView ID="grdddl" AutoGenerateColumns="false" ShowHeader="false" OnRowDataBound="grdddl_RowDataBound" ShowFooter="true" runat="server">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:DropDownList ID="ddlcommtype" SelectedValue='<%#Eval("ComPlanRoleDescr") %>' AutoPostBack="true" OnSelectedIndexChanged="ddlcommtype_SelectedIndexChanged" runat="server"></asp:DropDownList>
<asp:HiddenField ID="hdnid" Value='<%#Eval("ID") %>' runat="server" />
</ItemTemplate>
<FooterTemplate>
<asp:DropDownList ID="ddlcommtypefooter" AutoPostBack="true" OnSelectedIndexChanged="ddlcommtypefooter_SelectedIndexChanged" runat="server"></asp:DropDownList>
</FooterTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
protected void grdddl_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
DropDownList ddlcommtype = (DropDownList)e.Row.FindControl("ddlcommtype");
ddlcommtype.DataSource = listcommtype;
ddlcommtype.DataTextField = "ComPlanRoleDescr";
ddlcommtype.DataValueField = "ID";
ddlcommtype.DataBind();
}
if (e.Row.RowType == DataControlRowType.Footer)
{
DropDownList ddlcommtype = (DropDownList)e.Row.FindControl("ddlcommtypefooter");
ddlcommtype.DataSource = listcommtype;
ddlcommtype.DataTextField = "ComPlanRoleDescr";
ddlcommtype.DataValueField = "ID";
ddlcommtype.DataBind();
}
}
此代码给出错误:'ddlcommtype'有一个无效的SelectedValue,因为它不存在于项目列表中。
在您的GridView
中,您为DropDownList
设置了SelectedValue
,但是该值在下拉列表中的ListItem
中找不到。
删除SelectedValue
:
<asp:DropDownList ID="ddlcommtype" SelectedValue='<%#Eval("ComPlanRoleDescr") %>' AutoPostBack="true" OnSelectedIndexChanged="ddlcommtype_SelectedIndexChanged" runat="server"></asp:DropDownList>
如果你想使用SelectedValue
,为什么不在DataBind()
之后呢?例如:
DropDownList ddlcommtype = (DropDownList)e.Row.FindControl("ddlcommtype");
ddlcommtype.DataSource = listcommtype;
ddlcommtype.DataTextField = "ComPlanRoleDescr";
ddlcommtype.DataValueField = "ID";
ddlcommtype.DataBind();
// Now set the default value:
ddlcommtype.SelectedValue = "InsertValueHere";