anyone know how does it cause ASP.NET codebehind can’t acquire the selected value.
What I found is the problem is the javascript function;
set attribute portion:
process.options[process.selectedIndex].setAttribute("style", "color:red;font-weight:600;");
process.options[process.selectedIndex].setAttribute("disabled", "disabled");
If I remove these setAttribute portion, ASP.NET codebehind can acquire the selected value.
Any solutions? If I insist want to use the setAttribute portion
Sample:
HTML
<html>
<table style="margin-left: auto; text-align: center; margin-right: auto; font-size: large; width: 50%" border="1">
<tr>
<td class="auto-style1">Process Name</td>
<td class="auto-style2">:</td>
<td class="auto-style3">
<asp:DropDownList ID="ddl_processname" runat="server" CssClass="ddl-style" onchange="focustester()">
<asp:ListItem Value="P1">Process 1</asp:ListItem>
<asp:ListItem Value="P2">Process 2</asp:ListItem>
<asp:ListItem Value="P3">Process 3</asp:ListItem></asp:DropDownList>
<br />
<br />
<asp:Label ID="lbl_statio" runat="server" Text=""></asp:Label>
</td>
</tr>
<tr>
<td class="auto-style1">Tester Name</td>
<td class="auto-style2">:</td>
<td class="auto-style3">
<asp:TextBox ID="txt_testername" runat="server" AutoPostBack="true" OnTextChanged="TextBox_TextChanged" CssClass="txt-style"></asp:TextBox>
</td>
</tr>
</table>
</div>
<script>
function focustester() {
var process = document.getElementById('<%= ddl_processname.ClientID%>');
if (process.value != "") {
process.options[process.selectedIndex].setAttribute("style", "color:red;font-weight:600;");
process.options[process.selectedIndex].setAttribute("disabled", "disabled");
document.getElementById('<%= txt_testername.ClientID%>').focus();
}
}
</script>
</html>
ASP.NET code behind
protected void TextBox_TextChanged(object sender, EventArgs e)
{
TextBox txt_ID = (TextBox)sender;
string get_certain_box = "";
if (ddl_processname.SelectedValue.ToString() == "")
{
Response.Write(@"<script language=javascript>alert('Please select Process first...')</script>");
txt_ID.Text = "";
ddl_processname.Focus();
}
else
{
if (txt_ID.Text.ToString() == "")
{
get_certain_box = (txt_ID.ID.ToString() == "txt_testername") ? "Tester field" : "txtID";
Response.Write(@"<script language=javascript>alert('" + get_certain_box + " cannot blank...')</script>");
txt_ID.Focus();
}
else
{
if (txt_ID.ID.ToString() == "txt_testername")
{
Response.Write(@"<script language=javascript>alert('success')</script>");
}
}
}
}
2
Answers
I maybe wrong but I remember that code behind can’t get data if the dropdown is disabled or something.
So can you just disable dropdown after it go to focustester() ?
but if you insist to use JavaScript then why not workaround like insert value into hidden field when using setAttribute?
Add a hidden field. And then assign dropdown value to hidden field in javascript. In the server side access the hidden value for dropdown value.
Javascript
Server Side