Object reference not set to an instance of an object. Please help!

[coopsterdude]

Hi, my program compiles ok but when I click on a the control to execute this:

Public Sub numberUpdate(By Val theNum As Integer)



lblCurrentQuest ionNumber.Text = theNum


End Sub

I get this error message: System.NullRefe renceException: Object reference not set to an instance of an object.

Can anyone help me with this please?

[emilnordiclake]

You need to assign a value to theNum before passing it to the function.

For example:

theNum = 123

[CyberSoftHari]

Can you point here how you are calling above method? That will be helpful to describe the problem.

[coopsterdude]

Here is what my code looks like that I'm using to call:

Dim x As _default
x = New _default
Dim intSentNum As Integer
intSentNum = 1
x.numberUpdate( intSentNum)

Here's the sub that I call:

Public Sub numberUpdate(By Val inComingNum As Integer)

lblCurrentQuest ionNumber.Text = inComingNum


End Sub

For some reason, I get the same object reference error message.

[Plater]

Is lblCurrentQuest ionNumber declared correctly?
[code=vbnet]
Dim lblCurrentQuest ionNumber as Label
lblCurrentQuest ionNumber = new Label
[/code]

[coopsterdude]

lblCurrentQuest ionNumber is a control on the form. I did this to test your idea:

Dim lblCurrentQuest ionNumber As Label
lblCurrentQuest ionNumber = New Label
lblCurrentQuest ionNumber.Text = "e"

the code seems to create another label dynamically but it doesn’t access my label with the same name which is already on the form.

[Plater]

Hmm, does it correct itself if you use:
lblCurrentQuest ionNumber.Text = inComingNum.ToS tring

[coopsterdude]

I’m afraid I’ve tried that. I get the error message only when I try to assign a value to a property of the control. Even if I do this:

lblCurrentQuest ionNumber.text= ”hello”

I still get the error message

[Plater]

You are not calling this function BEFORE the InitializeCompo nent function are you? That would have to happen FIRST in order for the controls to be created properly.

[coopsterdude]

I created the control by dragging it onto the form so I think .NET takes care of any initializing issues. I can set the property of the control from a button that's on the form. I'm thinking of trying to call this button procedure and try to access the control this way. When I call a button, do you know what I need to provide for these parameters?

butNext_Click(B yVal sender As System.Object, ByVal e As System.EventArg s)

If I can successfully access the code inside this sub then I think I can troubleshoot the other problem.

Thanks for all your help!!

[Plater]

.NET does take care of the initialization stuff, by calling InitializeCompo nent in the constructor class for your form. So that would have to happen first.

public Form1()
        {
            InitializeComponent();
        }

If your function does not get called before that function does, I'm not sure what to tell you.

[coopsterdude]

I called the button successfully but got the same error. If I click on a button that executes the code, it works fine. When I try to execute that same line of code I get an error.

[Plater]

How are you calling that function in code? and WHERE in your code are you calling it?
You cannot access your windows controls until after that designer code function gets executed.

[CyberSoftHari]

as in #4
[CODE=cpp]//You are declaring the x here
Dim x As _default
/* And initializeing the X in below decleration or some where else? If Yes then you can use like Dim x As new _default, If no Here is the mistake happening because before calling the method where you initializing the x you are calling numberUpdate(By Val inComingNum As Integer) */
x = New _default[/CODE]

Better I suggest to keep a break point and debug it.

[priyamtheone]

I called the button successfully but got the same error. If I click on a button that executes the code, it works fine. When I try to execute that same line of code I get an error.

If ur idea is to write the code in butNext_Click event and call this event from elsewhere then U gotto call it in the following way:

dim a as System.Object
dim b as System.EventArg s
butNext_Click(a ,b)