Hi
Refer the below sample.
HTML
<asp:TextBox runat="server" ID="txtTest" OnTextChanged="TextChanged" AutoPostBack="true" />
<asp:Panel runat="server" ID="pnlDynamicDropdownlist">
</asp:Panel>
C#
protected void TextChanged(object sender, EventArgs e)
{
int items = Convert.ToInt32(txtTest.Text.Trim());
DropDownList ddl = new DropDownList();
ddl.ID = "ddlTest";
for (int i = 1; i <= items; i++)
{
ddl.Items.Add(new ListItem("RowNo." + i, i.ToString()));
}
pnlDynamicDropdownlist.Controls.Add(ddl);
}
VB.Net
Protected Sub TextChanged(sender As Object, e As EventArgs)
Dim items As Integer = Convert.ToInt32(txtTest.Text.Trim())
Dim ddl As New DropDownList()
ddl.ID = "ddlTest"
For i As Integer = 1 To items
ddl.Items.Add(New ListItem("RowNo." + i, i.ToString()))
Next
pnlDynamicDropdownlist.Controls.Add(ddl)
End Sub
If you have dropdownlist present in the html then refer the below code.
HTML
<asp:TextBox runat="server" ID="txtTest" OnTextChanged="TextChanged" AutoPostBack="true" />
<asp:DropDownList runat="server" ID="ddlItems">
</asp:DropDownList>
C#
protected void TextChanged(object sender, EventArgs e)
{
int items = Convert.ToInt32(txtTest.Text.Trim());
ddlItems.Items.Clear();
for (int i = 1; i <= items; i++)
{
ddlItems.Items.Add(new ListItem("RowNo." + i, i.ToString()));
}
}
VB.Net
Protected Sub TextChanged(sender As Object, e As EventArgs)
Dim items As Integer = Convert.ToInt32(txtTest.Text.Trim())
ddlItems.Items.Clear()
For i As Integer = 1 To items
ddlItems.Items.Add(New ListItem("RowNo." + i, i.ToString()))
Next
End Sub