Value of type 'Control' cannot be converted to 'CheckBox' in vb.net

Question

I am trying to use checkbox for multiple select in GridView to delete records.

Here is my Code :-

Protected Sub btnDelete_Click(sender As Object, e As EventArgs)
        Try
            'Loop through all the rows in gridview
            For Each grv As GridViewRow In GridView1.Rows
                'Finiding checkbox control in gridview for particular row
                Dim chk As CheckBox = CType(grv.FindControl("chkSelect"), CheckBox)
                If chk.Checked Then
                    'get EmpId from DatakeyNames from gridview
                    Dim empid As Integer = Convert.ToInt32(GridView1.DataKeys(grv.RowIndex).Value)
                    cmd = New SqlCommand("DeleteRecord_Sp", con)
                    cmd.Parameters.Add("@Id", SqlDbType.Int).Value = empid
                    cmd.CommandType = CommandType.StoredProcedure
                    cmd.ExecuteNonQuery()
                End If
            Next
            GridView1.EditIndex = -1
            DisplayData()
            ScriptManager.RegisterClientScriptBlock(Page, Page.[GetType](), Guid.NewGuid().ToString(), "alert('Selected Records has been deleted successfully');", True)
        Catch ex As Exception
            ScriptManager.RegisterStartupScript(Me, Me.[GetType](), "Message", "alert('Error occured : " & ex.Message.ToString() & "');", True)
        Finally
            cmd.Dispose()
            con.Close()
        End Try
    End Sub

Inside Grid View :-

              <asp:CheckBox ID="chkSelect" runat="server" />
      </ItemTemplate>
    <asp:Button ID="btnDelete" runat="server" Text="Multiple Delete"
         OnClientClick="return confirm('Are you sure you want to delete selected records?')"
         OnClick="btnDelete_Click" />

I am getting error in this line :-

Dim chk As CheckBox = CType(grv.FindControl("chkSelect"), CheckBox)

Value of type 'Control' cannot be converted to 'CheckBox' in vb.net

That seems strange but you should be using `DirectCast` anyway, so try that. — jmcilhinney, Mar 23 '21 at 09:57
I have tried DirectCast, Ctype, TryCast , but ain't working, and also i am new in asp.net — Akshay Makwana, Mar 23 '21 at 10:28
If you look at the page source of the rendered HTML, does it appear to be what you intended? — Andrew Morton, Mar 23 '21 at 12:37

score 0 · Answer 1 · answered Mar 24 '21 at 20:57

0

This is because Ctype returns a collection, and not a single item

you need DirectCast to cast a single item. But since you are catching it into a variable, you do not need to at all.

Dim chk As CheckBox = grv.FindControl("chkSelect")

But you might also simply Acces it by its name. without 'finding' it, and without catching it into a variable.

If ChkSelect.Checked then

end if

answered Mar 24 '21 at 20:57

fazioli fairmont

103
3

It will take this :- ```Dim chk = DirectCast(grv.FindControl("chkSelect"), HtmlInputCheckBox)``` `````` but not taking :- ```Dim chk As CheckBox = grv.FindControl("chkSelect")``` – Akshay Makwana Mar 25 '21 at 04:51

Value of type 'Control' cannot be converted to 'CheckBox' in vb.net

1 Answers1