maintain it yourself, for example <asp:DropDownList id="DropDownList1" runat="server" OnSelectedIndexChanged="ChangeSel">
.....
</asp:DropDownList>
void ChangeSel (Object o, EventArgs e)
{
int n = 0;
object ob = ViewState["OldSelectedIndex"];
if (ob != null)
n = (int)ob; Response.Write("old index:" + n+"<BR>"); n = DropDownList1.SelectedIndex; Response.Write("new index:" + n+"<BR>"); ViewState["OldSelectedIndex"] = n;
}
.....
</asp:DropDownList>
void ChangeSel (Object o, EventArgs e)
{
int n = 0;
object ob = ViewState["OldSelectedIndex"];
if (ob != null)
n = (int)ob; Response.Write("old index:" + n+"<BR>"); n = DropDownList1.SelectedIndex; Response.Write("new index:" + n+"<BR>"); ViewState["OldSelectedIndex"] = n;
}
解决方案 »
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