tags:

views:

657

answers:

2
Q: 

Type casting problem in code behind file

I have the below error message in my asp.net website when i replaced the textbox and put dropdown and named the dropdown id same as textbox id.

The value from the drop down should be taken and put in a email body and will be received as mail when i click on the submit button.

Below is the error i am getting when i click on the submit button.

System.InvalidCastException: Unable to cast object of type 'System.Web.UI.WebControls.DropDownList' to type 'System.Web.UI.WebControls.TextBox'. at WebApplication1._Default.collectEmailBodyText() in C:\v1.5_production_05June09\Default.aspx.vb:line 213

My code behind file is as follows :

''//------------------------------------------------------------------------------
''// <auto-generated>
''//     This code was generated by a tool.
''//     Runtime Version:2.0.50727.3053
''//
''//     Changes to this file may cause incorrect behavior and will be lost if
''//     the code is regenerated.
''// </auto-generated>
''//------------------------------------------------------------------------------

Option Strict On
Option Explicit On

Partial Public Class _Default

    Protected WithEvents form1 As Global.System.Web.UI.HtmlControls.HtmlForm

    Protected WithEvents MultiView1 As Global.System.Web.UI.WebControls.MultiView

    Protected WithEvents View0 As Global.System.Web.UI.WebControls.View

    Protected WithEvents lbl_viewTitle0 As Global.System.Web.UI.WebControls.Label

    Protected WithEvents lbl_view0_firstName As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txt_firstName As Global.System.Web.UI.WebControls.TextBox

    Protected WithEvents Validator_FirstName As Global.System.Web.UI.WebControls.RequiredFieldValidator

    Protected WithEvents lbl_view0_surname As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txtSurName As Global.System.Web.UI.WebControls.TextBox    

    Protected WithEvents Validator_Surname As Global.System.Web.UI.WebControls.RequiredFieldValidator

    Protected WithEvents lbl_view0_ContactNum As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txt_contactNum As Global.System.Web.UI.WebControls.TextBox

    Protected WithEvents Validator_ContactNumber As Global.System.Web.UI.WebControls.RequiredFieldValidator

    Protected WithEvents lbl_view0_typeOfRequest As Global.System.Web.UI.WebControls.Label

    Protected WithEvents ddl_view0_typeOfRequest As Global.System.Web.UI.WebControls.DropDownList

    Protected WithEvents lbl_view0_workUnitLevel As Global.System.Web.UI.WebControls.Label

    Protected WithEvents ddl_view0_workUnitLevel As Global.System.Web.UI.WebControls.DropDownList

    Protected WithEvents btn_view0_forward As Global.System.Web.UI.WebControls.Button

    Protected WithEvents View1 As Global.System.Web.UI.WebControls.View

    Protected WithEvents lbl_viewTitle1 As Global.System.Web.UI.WebControls.Label  

    Protected WithEvents lbl_view1_firstName As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txt_view1_firstname As Global.System.Web.UI.WebControls.TextBox

    Protected WithEvents lbl_view1_surname As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txt_view1_surname As Global.System.Web.UI.WebControls.TextBox

    Protected WithEvents lbl_view1_userID As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txt_view1_userID As Global.System.Web.UI.WebControls.TextBox

    Protected WithEvents lbl_view1_workUnit As Global.System.Web.UI.WebControls.Label

    Protected WithEvents ddl_view1_workunit As Global.System.Web.UI.WebControls.DropDownList

    Protected WithEvents panview0 As Global.System.Web.UI.WebControls.Panel

    Protected WithEvents lbl_panView0_label1 As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txt_panview0_input1 As Global.System.Web.UI.WebControls.TextBox

    Protected WithEvents panview2 As Global.System.Web.UI.WebControls.Panel

    Protected WithEvents lbl_panview2_label1 As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txt_panview2_input1 As Global.System.Web.UI.WebControls.TextBox

    Protected WithEvents panview1 As Global.System.Web.UI.WebControls.Panel

    Protected WithEvents lbl_panview1_label1 As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txt_panview1_input1 As Global.System.Web.UI.WebControls.TextBox   

    Protected WithEvents panview3 As Global.System.Web.UI.WebControls.Panel

    Protected WithEvents lbl_panview3_label1 As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txt_panview3_input1 As Global.System.Web.UI.WebControls.DropDownList

    Protected WithEvents lbl_panview3_label2 As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txt_panview3_input2 As Global.System.Web.UI.WebControls.TextBox

    Protected WithEvents btn_view1_back As Global.System.Web.UI.WebControls.Button

    Protected WithEvents btn_view1_forward As Global.System.Web.UI.WebControls.Button

    Protected WithEvents View2 As Global.System.Web.UI.WebControls.View

    Protected WithEvents lbl_viewTitle2 As Global.System.Web.UI.WebControls.Label

    Protected WithEvents lbl_view2_ManagersEmailAddress As Global.System.Web.UI.WebControls.Label

    Protected WithEvents txt_view2_ManagersEmailAddress As Global.System.Web.UI.WebControls.TextBox

    Protected WithEvents rfv_view2_managersEmail As Global.System.Web.UI.WebControls.RequiredFieldValidator

    Protected WithEvents rev_view2_managersEmail As Global.System.Web.UI.WebControls.RegularExpressionValidator

    Protected WithEvents btn_view2_back As Global.System.Web.UI.WebControls.Button  

    Protected WithEvents btn_view02_forward As Global.System.Web.UI.WebControls.Button

    Protected WithEvents View3 As Global.System.Web.UI.WebControls.View

    Protected WithEvents lbl_viewTitle3 As Global.System.Web.UI.WebControls.Label

    Protected WithEvents lit_preview As Global.System.Web.UI.WebControls.Literal

    Protected WithEvents btn_view3_submit As Global.System.Web.UI.WebControls.Button

    Protected WithEvents btn_view3_back As Global.System.Web.UI.WebControls.Button
End Class

Please help me !

A: 

In your code behind, it looks like in your FindControls you're trying to handle a DropDownList as a TextBox. You should verify that the object definitions in your .aspx and code behind correspond in their declarations and in FindControls.

Darth Continent  2009-06-09 17:56:00
Could you elaborate how to do this?
 2009-06-09 17:56:59
Well, for example, if in your .aspx page you have the following objects defined: <asp:DropDownList id="SomeDropDown" /> <asp:TextBox id="SomeTextBox" />Then in the code behind you would want declarations which are proper according to the object types: protected DropDownList SomeDropDown; protected TextBox SomeTextBox;And in your FindControls method, you would want something like: SomeDropDown = (DropDownList)this.Master.FindControl("ContentBody").FindControl("SomeDropDown"); SomeTextBox = (TextBox)this.Master.FindControl("ContentBody").FindControl("SomeTextBox");
Darth Continent  2009-06-09 18:32:16
Yes this is my code anything wrong below tempPanelLabel = form1.FindControl("lbl_" + panelUsed + "_label" + counter.ToString()) tempPanelInputBox = form1.FindControl("txt_" + panelUsed + "_input" + counter.ToString())
 2009-06-09 18:37:57
txt_" + panelUsed + "_input" + counter.SelectedItem.ToString())is this fine?
 2009-06-09 18:42:41
Yeah based on your code that looks like it should result in the proper object name for FindControls to acquire the control.
Darth Continent  2009-08-28 13:11:00
A: 

I would look for the control in the code behind file and change the:

Global.System.Web.UI.WebControls.TextBox

To:

Global.System.Web.UI.WebControls.DropDownList

What is the name of the control?

orandov  2009-06-09 17:59:37
lbl_panview3_label1
 2009-06-09 18:02:01
Thats a label control. Not a dropdownlist or a textbox.Am I missing something?
orandov  2009-06-09 18:06:44
sorry its txt_panview3_input1
 2009-06-09 18:11:06
The code behind file looks fine. I don't know what is causing the problem. Try closing everything (even VS) and reopening it.
orandov  2009-06-09 18:24:02
Oh, didn't realize this is a coding issue and not an issue with the controls and the designer.
orandov  2009-06-09 19:05:49

related questions

Subsonic Vs NHibernate
How to check For File Lock in C# ?
Is nAnt still supported and suitable for .net 3.5/VS2008?
Limit size of Queue<T> in .NET?
Viewstate invalid when using Safari
Free OCR library
Unhandled Exception Handler in .NET 1.1
Localising date format descriptors
Get a new object instance from a Type in C#
VFP .NET OLEdb provider does not work in Win 64-Bits. Help
.NET Testing Framework Advice
Embedded Database for .net that can run off a network
Automatically update version number
Homegrown consumption of web services
How do you migrate a large app from VB6 to VB .net ?
.NET Migrations Engine
Adding Scripting functionality to .NET applications
SQLite and XSD
Floating Point Number parsing: Is there a Catch All algorithm?
How do I programmatically create a PDF in my .NET application?
How do I sync the SVN revision number with my ASP.NET web site?
XSD DataSets and ignoring foreign keys
Anatomy of a "Memory Leak"
Reliable Timer in a Console Application
How do I calculate relative time?