Refer the below sample code and implement it as per your code logic.
HTML
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<style type="text/css">
body
{
font-family: Arial;
font-size: 10pt;
}
input[type=text]
{
margin-bottom: 10pt;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<asp:Panel ID="pnlDropDowns" runat="server">
</asp:Panel>
<hr />
<asp:Button ID="btnAdd" runat="server" Text="Add New" OnClick="AddDropDownList" />
<asp:Button ID="btnGet" runat="server" Text="Get Values" OnClick="GetDropDownListValues" />
</form>
</body>
</html>
C#
protected void Page_PreInit(object sender, EventArgs e)
{
List<string> DropDownkeys = Request.Form.AllKeys.Where(key => key.Contains("ddlDynamic")).ToList();
int i = 1;
foreach (string key in DropDownkeys)
{
this.CreateTextBox("ddlDynamic" + i, i);
i++;
}
}
protected void AddDropDownList(object sender, EventArgs e)
{
int index = pnlDropDowns.Controls.OfType<DropDownList>().ToList().Count + 1;
this.CreateTextBox("ddlDynamic" + index, index);
}
private void CreateTextBox(string id, int index)
{
DropDownList ddllst = new DropDownList();
ddllst.ID = id;
DataSet ds2 = new DataSet();
ds2 = Getdata();
if (ds2.Tables[0].Rows.Count > 0)
{
ddllst.DataSource = ds2.Tables[0];
ddllst.DataTextField = "Name";
ddllst.DataValueField = "Id";
ddllst.DataBind();
ddllst.Items.Insert(0, new ListItem("--Select--"));
}
else
{
ddllst.DataSource = null;
ddllst.DataBind();
ddllst.Items.Insert(0, new ListItem("--Select--"));
}
pnlDropDowns.Controls.Add(ddllst);
Literal lt = new Literal();
lt.Text = "<br />";
pnlDropDowns.Controls.Add(lt);
}
protected void GetDropDownListValues(object sender, EventArgs e)
{
string message = "";
foreach (DropDownList dropDownList in pnlDropDowns.Controls.OfType<DropDownList>())
{
message += dropDownList.ID + ": " + " Text :" + dropDownList.SelectedItem.Text + " value :" + dropDownList.SelectedItem.Value + "\\n";
}
ClientScript.RegisterClientScriptBlock(this.GetType(), "alert", "alert('" + message + "');", true);
}
private DataSet Getdata()
{
DataSet ds = new DataSet();
DataTable dt = new DataTable();
dt.Columns.AddRange(new DataColumn[2]
{
new DataColumn ("Id",typeof(string)),
new DataColumn ("Name",typeof(string))
});
dt.Rows.Add("1", "Test 1");
dt.Rows.Add("2", "Test 2");
dt.Rows.Add("3", "Test 3");
dt.Rows.Add("4", "Test 4");
ds.Tables.Add(dt);
return ds;
}
VB.Net
Protected Sub Page_PreInit(sender As Object, e As EventArgs) Handles Me.PreInit
Dim keys As List(Of String) = Request.Form.AllKeys.Where(Function(key) key.Contains("ddlDynamic")).ToList()
Dim i As Integer = 1
For Each key As String In keys
Me.CreateDropDownList("ddlDynamic" & i, i)
i += 1
Next
End Sub
Protected Sub AddDropDownList(sender As Object, e As EventArgs)
Dim index As Integer = pnlDropDowns.Controls.OfType(Of DropDownList)().ToList().Count + 1
Me.CreateDropDownList("ddlDynamic" & index, index)
End Sub
Private Sub CreateDropDownList(id As String, index As Integer)
Dim ddllst As New DropDownList()
ddllst.ID = id
Dim ds = New DataSet()
ds = GetData()
If ds.Tables(0).Rows.Count > 0 Then
ddllst.DataSource = ds.Tables(0)
ddllst.DataTextField = "Name"
ddllst.DataValueField = "Id"
ddllst.DataBind()
ddllst.Items.Insert(0, New ListItem("--Select--"))
Else
ddllst.DataSource = Nothing
ddllst.DataBind()
ddllst.Items.Insert(0, New ListItem("--Select--"))
End If
pnlDropDowns.Controls.Add(ddllst)
Dim lt As New Literal()
lt.Text = "<br />"
pnlDropDowns.Controls.Add(lt)
End Sub
Protected Sub GetDropDownListValues(sender As Object, e As EventArgs)
Dim message As String = ""
For Each dropDownList As DropDownList In pnlDropDowns.Controls.OfType(Of DropDownList)()
message += dropDownList.ID + ": " + " Text :" + dropDownList.SelectedItem.Text + " value : " + dropDownList.SelectedItem.Value + "\n"
Next
ClientScript.RegisterClientScriptBlock(Me.GetType(), "alert", "alert('" & message & "');", True)
End Sub
Private Function GetData() As DataSet
Dim ds As DataSet = New DataSet()
Dim dt As DataTable = New DataTable()
dt.Columns.AddRange(New DataColumn(1) {New DataColumn("Id", GetType(String)), New DataColumn("Name", GetType(String))})
dt.Rows.Add("1", "Test 1")
dt.Rows.Add("2", "Test 2")
dt.Rows.Add("3", "Test 3")
dt.Rows.Add("4", "Test 4")
ds.Tables.Add(dt)
Return ds
End Function
Screenshot
