VS 2010 Control Creation And NullReferenceException?
Sep 9, 2011
i have issue with simple thing
Dim TblPans As List(Of TableLayoutPanel)
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Try
TblPans.Add(New TableLayoutPanel)
i frequently have troubles with the dock property. it seems that either the order of creation or adding to the parent control determines whether or not a control's dock property supersedes another's. e.g. a control with the dockstyle fill will overlap with another docked control on the same parent. does anyone know what the rules are to determine how docking will behave; particularly in dynamically created GUIs?
I ran into a little problem where my thread(s) tries to access a control that may not be created yet. How can I check for this or is there a way to force the creation of the control(s) first and then go on or any other solution?
As a test, my boss asked me to convert a (not very critical) ASP.NET site from 1.1 to 4.0. Well, it's not extremely difficult and things are going well so far. However, I've hit a small snag. I keep getting a NullReferenceException when I run this code:
Public Property PageTitle() As String '=========================================================================== 'Exposes the PageTitle property of the child control.
I want to make a new RichTextBox contorl when a new tab page is created. I also need that control to be the child of the tab page. I created a class for the tab control. And a class for the RichTextBox control. I dont know how to start this. I have made a class for the RTB because I figured I could override the sub new procedure but you can't so i just declared it as public and set what I needed it to do. But it doesn't work.
I want to make a new RichTextBox contorl when a new tab page is created. I also need that control to be the child of the tab page.
I created a class for the tab control. And a class for the RichTextBox control.
I dont know how to start this. I have made a class for the RTB because I figured I could override the sub new procedure but you can't so i just declared it as public and set what I needed it to do. But it doesn't work.
I am trying to make a program that will include a drag/drop view where you can arrange objects around in a view and add/delete objects as needed (objects are actually controls I create dynamically), I have made some code which I include below.If I run this code it works but not the part when I click on a newly created control, then mousemove function is not used, I should be able to move controls using the mouse functions..but these do not work. I thought code like:
I'm getting a 'NullReferenceException was unhandled' exception when a NumericUpDown control is cycled too quickly. To slow it down I've disabled the (NUD) control and set a 200 Interval Timer to re-enable it, but the exception is still happening.I don't want the slow the control down any further, I'd rather try to handle the exception, but can't find any help on how to do that.This is essentially the code which is incurring the exception, at the (4th) line... Dim p... : -
For b = 0 To 8 z = Pic(b)
[code]....
I figure I need to ensure each image is happily installed in it's 'Box before I try to load the next one, or it may be that I just need to check that the last one is 'in' before I call the next bit of code (which calls this bit again if I'm too fast) It all works perfectly well if I don't go too fast.
I basically made a listbox, a button, and a popup window. The button openes the popup window, in that window you type some text, press "OK" and the text gets added to a list box. Simple right? Guess not...-Textbox1 is the textbox in wich you input text.-Label1 is the label on the popup window that tells you what to do. It's text is either "Edit name:" or "Input name:"This is the function if you click "OK".
If Label1.Text = "Edit name:" And Textbox1.TextLenght > 0 Then Form1.name_list.Items.Remove(Form1.name_list.SelectedItem) Form1.name_list.Items.Add(ime_osebe.Text) Else
how you init a variable when it is created by assigning the value on the same line in which it is declared. Is there a way to do this with members of a structure?
I'm converting another project from VS2003 to VS2010 and am getting this message in the Immediate Window before I hit my MyBase.Load. From the warning, it looks like somting is undefined yet is being used - causing an exception. How can I trace this down?My app uses 2 DLLs, could the msg be coming from them during their load?
I would like to fine-tune their work tool.The basic idea is to load different libraries etc CppThere in my working environment, such as files - *. dsm.Read the information from them is no mean feat.
Just getting started in VB.NET. I would like to add X-number of text boxes at run time. And then be able to address them by their index or some sequential numerical value (like an array)
This is what I have so far:
CODE:
When I turn this into a loop to create multiple toolboxes, how do I assign a name to the controls, or will all of them be named "MyTextBox" ? I'll increment their position so thats no problem.
I am trying to send keys to a control on my form. But I am getting a NullReferenceException and I don't know why. The code is about as basic as it gets: [Code] The error reported is object reference not set to an instance of an object but Send is a shared method so doesn't need an instance. Strangely if I ignore the error it works fine and F4 is passed to the control. I know there was an issue with sendkeys and UAC but I thought this had been solved (I am using 4.0 framework).
I have been able to associate a listview control with an imageview control to display images. There are a couple of things, I would like to do.
1> How do I display the image in the second column? 2> How do I increase the size of the image getting displayed? My images are all 48 x 48 (pixels), but they keep shrinking.
I'm trying to make a program with transparent labels over pictureboxes and when I set the label Parent to the PictureBox the position of the label changes.
I am new to VB .NET, but not to DLL creation (C++).I am trying to create a DLL using VB .NET (2008) and I need to execute some code when the DLL loads. I am trying to do this in DllMain, but I don't see how to get DllMain to execute when the DLL is loaded. I don't see anywhere that the DllEntryPoint can be set in a VB .NET DLL.
I am using Microsoft visual basic 2010 express edition and i am having some trouble with my web browser i have gotten everything to work except for 6things.How to make the source code appear in note pad when i click view source
This never happened to me, and the less data one has (usually) the less you can say what happened.I am trying to write a simple query analyser. I randomly receive these kind of crashes:
[Code]...
The file specified above does not exist. The place where it crashes is wrapped with Try-End Try. Moreover, yes, I have the painting event set up but it should not concern it (or maybe it does?). I have to add that I use visual basic express edition. The error occurs ocasionally - sometimes when I'm lucky nothing happens, and when I'm not then I get this crash.
When I debug a program my IDE simply does not catch System.NullReferenceException - execution continues as if there were nothing wrong.Moreover, when I go to the menu Debug/Exceptions System.NullReferenceException is not even in the list(Common Language Runtime Exceptions).
I manually add it (there is the Add button) and I put a checkmark in the 'Thrown' and 'User unhandled' column - now IDE catches it, but after I re-load the project the situation re-appears - and NullReferenceException is not on the list again. What may be wrong?
Update:No, when I step through the code the execution does not continue but exits the current block of code (sub or function). There were no Try...Catch blocks and there is a message: A System.NullReferenceException occured in MSCorlib.dll... But why doesn't the debugger stop at this line?
How can I get a NullReferenceException in the following scenario?
Dim langs As IEnumerable(Of SomeCustomObject) = //some LINQ query If langs Is Nothing Then Return Nothing If langs.Count = 1 Then //NullReferenceException here
What am I missing here? Debug shows that langs is really just a LINQ queryresult without any results...
Okay after searching two listbox's on a form I am trying to put a number as a string in a label setup for that but keep exgetting a NullReferenceexception error on the label. Label being "shippingDataLabel.text".e is my code;
Public Class MainForm Dim fifteenShipping As Integer = 15 Dim twentyShipping As Integer = 20
I have a VB.NET solution that I just upgraded. It was originally in .NET 1.1, I upgraded to .NET 2.0 and verified that it would build and run correctly. Then I upgraded from 2.0 to 4.0. It is still building with no errors, but when I try to run I am getting a NullReferenceException in Global.asax.vb. The really weird thing is, the line that is throwing the exception is this:
Dim dt As System.Data.DataTable I am not trying to use the variable, just declare it. Further down a Function is called that returns a DataTable and sets the variable, but I don't even get to that line. It is throwing the NullReferenceException on the Dim line. Has anyone run across this before? Is this some issue with upgrading?
[Code]...
I did a Rebuild Solution before posting. This is a web application and the only files I see in the bin folder are the dll files I am referencing. I'm not sure what else I should clean up.