Set Null Pointer In Program?
Sep 17, 2009I am using a DLL written in C#, and one of its API's wants to be used as such, (this is the sample useage they give, but it is also written in C#)[code]...
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Null Pointer Exception From VB Code?
May 4, 2009I am using Windows Vista x64 + VSTS 2008. I am debugging the sample program from the following URL (associated sample code for this article),
http://www.codeproject.com/KB/audio-video/CaptureScreenAsVideo.aspx?display=PrintAll&fid=129831&df=90&mpp=25&noise=3&sort=Position&view=Quick&fr=101&select=1160633
But I met with null pointer exception when press the write to file button, here is my screen snapshot.
http://tinypic.com/view.php?pic=14cbfop&s=5
[Code]...
VS 2008 Pointer - Error32'System.Reflection.Pointer' Has No Type Parameters And So Cannot Have Type Arguments
Jul 15, 2010I have an open source project I converted to vb.net. I solved all the errors, except for one. This is the C# line
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C++ - Declare Pointer To Pointer In COM/ATL?
Dec 29, 2010How can I declare pointer to pointer in ATL. Actually I have a handle which I want to pass by address to function. As shown below
STDMETHODIMP Function(HANDLE* hHC) //HANDLE declared as void * so actual type is void **
OR
STDMETHODIMP Function(LONG **hHC)
And want to access this function from the VB client.
Getting A Null Reference Exception W/program?
Jul 19, 2009I keep getting a null reference exception w/this program, and its on the line that declares the array. I've looked it over and over and I just don't see why... Can you let me know if you see anything obvious? I'm also getting an "index out of range" exception, but it looks right to me...I declared everything with an 11 for 12 months, 0 to 11 for the intcount.
[Code]...
VS 2010 Remove Null / Unused Arrays From A Program?
Sep 19, 2011How to remove unused arrays from a program? The array is has an upper bound of 19. If the array isn't full, I get a null array error.
View 9 RepliesNull Reference Exception In Line Checking For Null?
Dec 15, 2011I have a fairly simple piece of code:
Private _PurchaseDelivery as PurchaseDelivery
Protected Overrides Sub InsertItem(ByVal index As Integer, ByVal item As PurchaseDeliveryItem)
[Code]....
Which is inside a class which overrides a custom list base. The code is occassionaly throwing an unhandled exception, System.NullReferenceException, on this line when used in production:
If _PurchaseDelivery IsNot Nothing AndAlso _PurchaseDelivery.DefaultSKUBinID.HasValue Then
DeafultSKUBinID is declared as an Integer? (Nullable Int) in the PurchaseDelivery class. I cannot see what might be causing this error, why would this be returning an error?
Linq To Sql Null - Check Whether A Column Is Null
Jul 15, 2011How to check whether a column is null i use the following code but I got this error "Input string was not in a correct format."
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SQL Exception (adding A Null Value To A Non-null Column)
Aug 12, 2009When I put a break point to the last if clause in the sub ("If (backOrder < 0) Then", see below) it runs until the break point, if I put the break point further below, I get the following error:
Cannot insert the value NULL into column 'OrderID', table 'WHM.dbo.OrderDetails'; column does not allow nulls. INSERT fails. The statement has been terminated.
I've discovered first hand that it only happens when prodqty is bigger then qtyOnStock, thus executing the if clause.
The code:
Private Sub NCOSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles NCOSubmit.Click
Dim sqlText As String = ""
[Code]....
VS 2005 What Can Use Instead Of A Pointer
May 1, 2010I understand there are no pointers in VB.Net. I need to use something similar.The issue is that I have a structure that represent a deck of cards, with elements showing how many of each type of card there is. So I have my_deck.ace, my_deck.two, and so on.What I want to do is set a pointer called current_element that refers to any element in the structure. It may one time point to my_deck.three, and another time to my_deck.nine, and so on. It could point to any element.What I want to do is, for instance to set current_element to point to my_deck.ace, then decrementing current_element would reduce the count of aces by one.[code]that would work, but it's inelegant, I have about 30 different operations to perform, some of them using several lines of code. I'd like to avoid this if at all possible. I could tolerate doing it 2 or 3 times, but not 30.
View 8 RepliesChange The Pointer To Custom?
Oct 11, 2009I need to change the default windows pointer to this: not generally, just in my program. (Form1) There's a Pointer Control But I Dont Know What That Does.
View 7 RepliesCompiled C Dll Can't Set Pointer When Called From ASP.NET App?
Dec 10, 2009I've got a 3rd party C application that's compiled to a non-.NET non-COM DLL. It has one simple function declared like so: Declare Function CapiTaxRoutine Lib "taxcommono.dll" (ByVal sInData As String, ByVal OutputData As String, ByVal intINPutLength As Long) As Integer
If I place the taxcommono.dll in my path (C:WindowsSystem32 is what I'm using because it's what the vendor recommends),I can wire up a call to the function and it works just fine.It returns a 1 or 0 for success/failure, but it also sets the value of the OutputData string parameter (using some C pointer magic I'm not familiar with) to a huge fixed width format return record that has the data I need.When I call it from a .NET .exe application, it works just fine.When I try to call it from an ASP.NET application via a referenced compiled .NET wrapper DLL, it runs but can't set that string.In order to get it to run, I can't have taxcommono.dll in my path, but rather have to place it in my Bin directory of the web project.Does anyone know of a reason it can set the pointer when called from an .exe application but not when called from a web app?The .NET wrapper DLL I'm using works when called from our ERP software, which is not web based. But when I add a reference to that same DLL in the web app, it won't give me that output value.am used to just getting a return value instead of a function setting the value of one of my input parameters.
Create A Pointer To A Form?
Feb 10, 2010In VB6 I have several child forms that have Subs and Controls with the same names.I need to access these Subs and Controls from public subs (in a module) that have a reference to the Active Form.[code]...
View 1 RepliesCreate Pointer To Value Types?
Nov 12, 2010I'm by no means a good programmer and I'm just trying to wrap my head around some of this stuff, so please forgive me if this is a dumb question.I want the following to produce a message box that says "2", not "5":
Public Class SomeClass
Private SomeInt As Integer = 5
Private SomeListOfInts As New List(Of Integer)
[code].....
How To Change The Cursor Pointer
Mar 30, 2009im in a project using drag and drop events and.. , when i drag a label image, i need to change te cursor pointer from an image that is on a labelike the SO windows when you drag a file appears like a mirror with alfa minimun so its like the image but more transparent when i drag i need to change the cursor pointer from an image that i'm dragging by the way im, using visual studio .net and im programming in visual basic
View 6 RepliesHow To Get The Function Pointer From Class
Nov 5, 2011Public Class Form1 Public Declare Function GetModuleHandle Lib "kernel32" Alias "GetModuleHandleA" (ByVal lpModuleName As String) As IntPtr Public Declare Function GetProcAddress Lib "kernel32" Alias "GetProcAddress" (ByVal hModule As IntPtr, ByVal lpProcName As String) As IntPtr
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim hmod As IntPtr = GetModuleHandle(Nothing) 'Work Dim addrs As IntPtr = GetProcAddress(hmod , "TestFunction") 'Not work, always NULL why??
Mouse Pointer As Icon?
Feb 20, 2012How do I change my mouse cursor/icon to use a image or icon. I want to make a simple "wack a mole" type game but I dont know how to change the pointer to a icon or at least get a image to follow the pointer.
View 7 RepliesObject Properties Via Pointer?
Feb 23, 2010I have a form that has 100 text boxes with 100 coinciding labels. I want them hidden until another function populates the text boxes with data gathered elsewhere. The data could be between 1 and 100.
I would like one loop where I can assign the data to the correct text box, set it visible and set the label visible. I can not figure out how to do this in VB, or know if it is even possible.
Here is an example of what I would like to do
Dim i As Long = 1
Dim textbox As String = "textbox"
[code]....
I would also like to do this to hide all the items on the form in the on load event.
Passing A Pointer To A Structure To A C DLL?
Sep 28, 2010Private Declare Function src_simple Lib "libsamplerate.dll" (ByVal data As IntPtr, ByVal converter_type As Integer, ByVal channels As Integer) As Integer<br/>
Private Declare Function src_strerror Lib "libsamplerate.dll" (ByVal err As Integer) As IntPtr<br/>
<br/>
<StructLayout(LayoutKind.Sequential, Pack:=1)> _
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Pointer - Rewrite A C++ Library
Jan 4, 2012I'm trying to rewrite a C++ library. But I have an issue. I'm not extremely pointer-savvy. In the C++ class there is a std::vector that holds unsigned int pointers (vector<unsigned int*>), and the int pointer just points to an array of integer data.
Here is the C++ code I'm a bit unsure about:
unsigned int* relocation = m_relocations.front();
m_relocations.pop();
unsigned int* reloc = *(unsigned int **)relocation;
Reading A Structure Using A Pointer?
May 3, 2011I am trying to use VirtualQueryEx to read the memory of a process (first instance of notepad in this case). This function returns a pointer to the MEMORY_BASIC_INFORMATION structure. I am trying to read this structure.But everytime I try to access a member of the structure, I get a zero, which indicates I am messing something up.I am copying my code here.
-Coder_in_distress
Imports System.Runtime.InteropServices
Module Module1[code].....
Show The Pointer In The TextBox2
Apr 23, 2009I have three TextBoxes, how can I let the pointer show in the TextBox2 when I load the Form I treid this but didn't succeed
Me.TextBox2.Focus()
Using Pointer To Type In Dictionary Value?
Feb 23, 2011This small snippet of code is to increment a count value (integer) which is stored in a dictionary using my referenced object as a key. When the dictionary is small, multiple lookups aren't a big deal but this particular dictionary can get quite large.
Private RefCount As IDictionary(Of ILifeTimeManaged, Integer)
......... CODE HERE.....
Private Sub IncrementRefCount(ByVal entity As ILifeTimeManaged)
Dim prevCount As Integer
''# if we have no reference entry, add one and set its count to 1
[Code] .....
I find a corresponding dictionary entry then increment the int stored in the value, or add a new dictionary entry. Is it a bad idea to use a pointer to the dictionary value? Then I can avoid the second key lookup when I already have gotten the value. How would you implement it? Is this even possible in .NET4? Can I do it using IntPtr do you think? [URL]
RefCount.Item(entity) = prevCount + 1
VS 2008 - What Is Different From A Delegate To A Pointer
Feb 2, 2010I have been looking into delegates today, have come across them a few times but haven't understood them. I started thinking today that a Delegate is like a Pointer (for those who don't know a pointer is a reference to a location used in C++ and other languages than VB) So how much of a pointer is a delegate? what can a delegate do that a pointer/pointers cant?
Similarly does anyone else agree with me that all .NET languages should be able to do the same things, why cant i use pointers or logical shift operators in VB.NET? Would you guys think that being able to use code from any .net language within your code would be advantageous?
VS 2008 API String Pointer?
Aug 28, 2010I'm calling an API that returns a string pointer but I can't find anyway to return the string it points to.
Is it possible in VB.Net, I see VB6 had a STRPTR function but I can see a .net alternative.
Which Mouse Pointer Is Selected
Aug 25, 2010I want to know which mouse pointer is selected anywhere in windows (so also outside my application).
I've looked into Cursor.Current but I can't figure it out. Perhaps someone here can tell me how it's done?
Wpf :: Hide Mouse Pointer?
May 13, 2011I am attempting to hide the mouse pointer when there has been a few seconds of inactivity and then re-show the pointer again when the user moves the mouse. I have been able to get the mouse pointer to hide and re-show as I require it, however when I execute grid.Children.Clear() and grid.Children.Add() the mouse pointer re-appears (but again hides after a few seconds of inactivity).
My code is as below:
Private Sub Window1_MouseMoved(ByVal sender As Object, ByVal e As MouseEventArgs) Handles MyBase.MouseMove
[code]....
Change Mouse Pointer On Timer_Tick?
Feb 26, 2009Change mouse pointer on Timer_Tick? [code]...
View 6 RepliesHow To Convert Packed DIB Pointer To Bitmap
Nov 13, 2011I've searched all day and did not find any for vb language this my code,but it does not work.[code]I can add a bitmap to stream and see the results with Windows Media Player [code] but I do not know how to convert Dib ptr to a bitmap or hbitmap.
View 2 RepliesImage Follow Mouse Pointer?
Apr 17, 2012i want to make a custom mouse cursor but I found that can be hard so I want to go the next best route. I want to see how you make an image follow the mouse pointer. I assume it would use some kind of image = mousepinter new point (x, y) or somethign like that. Suggestions or samples? In the end i want to take this code snippet and make a duck hunt game and a whack a mole type game
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