Dear All,
I'm using this link http://www.aspforums.net/Threads/101989/Dynamically-add-and-remove-TextBox-and-save-value-to-Database-with-UserControl-using-C-and-VBNet-in-ASPNet/
But im getting the error in This Line
UserControl DynamicUserControl = (UserControl)LoadControl("WebUserControl1.ascx");
Error: Sys.WebForms.PageRequestManagerServerErrorException: Unable to cast object of type 'ASP.webusercontrol1_ascx' to type 'StrategicKPI.UserControl'
Usercontrol:
<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="WebUserControl1.ascx.cs" Inherits="StrategicKPI.WebUserControl1" %>
<link href="css/bootstrap.min.css" rel="stylesheet" />
<table class="table table-bordered">
<tr>
<td colspan="4">
Twice a year KPI Data Insertion
</td>
</tr>
<tr>
<td>
Enter Year
</td>
<td>
Select Quater
</td>
<td>
Enter Year Value
</td>
<td></td>
</tr>
<tr>
<td>
<asp:TextBox ID="txt_year" runat="server"></asp:TextBox>
</td>
<td>
<asp:DropDownList ID="dropdown_quater" runat="server">
<asp:ListItem Value="0">Q1</asp:ListItem>
<asp:ListItem Value="1">Q2</asp:ListItem>
</asp:DropDownList>
</td>
<td>
<asp:TextBox ID="txt_yearvalue" runat="server"></asp:TextBox>
</td>
<td>
<asp:Button ID="btnRemove1" runat="server" Text="Remove" CssClass="btn btn-danger" OnClick="btnRemove1_Click" />
</td>
</tr>
</table>
public partial class WebUserControl1 : System.Web.UI.UserControl
{
public event EventHandler RemoveUserControl1;
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnRemove1_Click(object sender, EventArgs e)
{
RemoveUserControl1(sender, e);
}
}
Page:
<%@ Register Src="WebUserControl1.ascx" TagName="UserControl1" TagPrefix="uc2" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<div>
<asp:ScriptManager ID="sm1" runat="server" />
<asp:UpdatePanel ID="up1" runat="server">
<ContentTemplate>
<div class="demo">
<table>
<tr>
<td>
<asp:PlaceHolder ID="ph1" runat="server" />
<br />
<asp:Button ID="btnAdd" runat="server" Text="Add" />
</td>
</tr>
</table>
</div>
</ContentTemplate>
</asp:UpdatePanel>
<br />
<asp:Button ID="btnInsert" runat="server" Text="Insert" OnClick="btnInsert_Click" />
<asp:Literal ID="ltlCount" runat="server" Text="0" Visible="false" />
<asp:Literal ID="ltlRemoved" runat="server" Visible="false" />
<br />
<br />
<asp:GridView runat="server" ID="gvInsertedRecords" />
</div>
</asp:Content>
protected void Page_Load(object sender, System.EventArgs e)
{
AddAndRemoveDynamicControls();
}
private void AddAndRemoveDynamicControls()
{
//Determine which control fired the postback event.
Control c = GetPostBackControl(Page);
if ((c != null))
{
//If the add button was clicked, increase the count to let the page know we want to display an additional user control
if (c.ID.ToString() == "btnAdd")
{
ltlCount.Text = (Convert.ToInt16(ltlCount.Text) + 1).ToString();
}
}
//Be sure everything in the placeholder control is cleared out
ph1.Controls.Clear();
int ControlID = 0;
//Since these are dynamic user controls, re-add them every time the page loads.
for (int i = 0; i <= (Convert.ToInt16(ltlCount.Text) - 1); i++)
{
UserControl DynamicUserControl = (UserControl)LoadControl("WebUserControl1.ascx");
//If this particular control id has been deleted from the page, DO NOT use it again. If we do, it will
//pick up the viewstate data from the old item that had this control id, instead of generating
//a completely new control. Instead, increment the control id so we're guaranteed to get a "new"
//control that doesn't have any lingering information in the viewstate.
while (InDeletedList("uc2" + ControlID) == true)
{
ControlID += 1;
}
//Note that if the item has not been deleted from the page, we DO want it to use the same control id
//as it used before, so it will automatically maintain the viewstate information of the user control
//for us.
DynamicUserControl.ID = "uc2" + ControlID;
//Add an event handler to this control to raise an event when the delete button is clicked
//on the user control
DynamicUserControl.RemoveUserControl += this.HandleRemoveUserControl;
//Finally, add the user control to the panel
ph1.Controls.Add(DynamicUserControl);
//Increment the control id for the next round through the loop
ControlID += 1;
}
}
private bool InDeletedList(string ControlID)
{
//Determine if the passed in user control id has been stored in the list of controls that were previously deleted off the page
string[] DeletedList = ltlRemoved.Text.Split('|');
for (int i = 0; i <= DeletedList.GetLength(0) - 1; i++)
{
if (ControlID.ToLower() == DeletedList[i].ToLower())
{
return true;
}
}
return false;
}
public void HandleRemoveUserControl(object sender, EventArgs e)
{
//This handles delete event fired from the user control
Button remove = (sender as Button);
//Get the user control that fired this event, and remove it
UserControl DynamicUserControl = (UserControl)remove.Parent;
ph1.Controls.Remove((UserControl)remove.Parent);
//Keep a pipe delimited list of which user controls were removed. This will increase the
//viewstate size if the user keeps removing dynamic controls, but under normal use
//this is such a small increase in size that it shouldn't be an issue.
ltlRemoved.Text += DynamicUserControl.ID + "|";
//Also, now that we've removed a user control decrement the count of total user controls on the page
ltlCount.Text = (Convert.ToInt16(ltlCount.Text) - 1).ToString();
}
protected void btnAdd_Click(object sender, System.EventArgs e)
{
//Handled in page load
}
protected void btnInsert_Click(object sender, System.EventArgs e)
{
DataTable dt = new DataTable();
dt.Columns.AddRange(new DataColumn[] { new DataColumn("StateId"), new DataColumn("State") });
foreach (Control c in ph1.Controls)
{
//Find the specific user control that we added to this placeholder, and then get the selected values
//for the dropdownlist, checkbox, and textbox and print them to the screen.
if (c.GetType().Name.ToLower() == "usercontrol_ascx")
{
UserControl uc2 = (UserControl)c;
TextBox tbState = uc2.FindControl("txtState") as TextBox;
TextBox tbStateId = uc2.FindControl("txtStateId") as TextBox;
if (!string.IsNullOrEmpty(tbStateId.Text.Trim()) && !string.IsNullOrEmpty(tbState.Text.Trim()))
{
dt.Rows.Add(tbStateId.Text.Trim(), tbState.Text.Trim());
//Insert(tbStateId.Text.Trim(), tbState.Text.Trim());
}
}
}
gvInsertedRecords.DataSource = dt;
gvInsertedRecords.DataBind();
}
private void Insert(string state, string id)
{
string constr = ConfigurationManager.ConnectionStrings["ConString"].ConnectionString;
using (SqlConnection con = new SqlConnection(constr))
{
string query = "INSERT INTO tblStates VALUES (@StateId, @State)";
using (SqlCommand cmd = new SqlCommand(query))
{
cmd.Connection = con;
cmd.Parameters.AddWithValue("@StateId", id);
cmd.Parameters.AddWithValue("@State", state);
con.Open();
cmd.ExecuteNonQuery();
con.Close();
}
}
}
//Find the control that caused the postback.
public Control GetPostBackControl(Page page)
{
Control control = null;
string ctrlname = page.Request.Params.Get("__EVENTTARGET");
if ((ctrlname != null) & ctrlname != string.Empty)
{
control = page.FindControl(ctrlname);
}
else
{
foreach (string ctl in page.Request.Form)
{
Control c = page.FindControl(ctl);
if (c is System.Web.UI.WebControls.Button)
{
control = c;
break;
}
}
}
return control;
}
}
Thanks in advance
