Solved

Thread Problem... AGIAN!

Posted on 2004-04-23
1
214 Views
Last Modified: 2010-04-01
#pragma once

namespace example
{
     using namespace System;
     using namespace System::ComponentModel;
     using namespace System::Collections;
     using namespace System::Windows::Forms;
     using namespace System::Data;
     using namespace System::Drawing;
     mytest * obj1;
     static void __cdecl testthread(void * dummy)
     {
          obj1 = new mytest();
     }
     public __gc class Form1 : public System::Windows::Forms::Form
     {    
     public:

          Form1(void)
          {
               InitializeComponent();
               _beginthread(testthread, 0, NULL);
          }

     protected:
          void Dispose(Boolean disposing)
          {
               if (disposing && components)
               {
                    components->Dispose();
               }
               __super::Dispose(disposing);
          }
     private: System::Windows::Forms::ListBox *  listBox1;
     private: System::Windows::Forms::ListBox *  listBox2;

     private:
          System::ComponentModel::Container * components;
          void InitializeComponent(void)...
==========================================================================

I created a thread using _beginthread , but the problem is that I want the function testthread to be able to modify
the components in my windows form, (such as listbox or combobox)
But by creating that testthread function outside the class i am not able to access the component of Form1.. (very obvious :P)
I tried creating the thread inside the Form1(VOID) function, but it would never compile..
I think there is someway to create a thread inside the Form1 class so that the function is going to be able to update on the windows form component while the windows form can take user inputs.

Can anyone please help out on this?
thanks
0
Comment
Question by:lordiano
1 Comment
 
LVL 48

Accepted Solution

by:
AlexFM earned 125 total points
Comment Utility
_beginthread is C++ Run-Time Library function, and you are trying to apply it from managed application. You need to use managed Thread class instead of unmanaded _beginthread function.
Running managed thread is relatively simple, but it has one restriction: it's impossible to update windows form directly from the worker thread. To do this you need to use Control::BeginInvoke or Control::Invoke functions. The following article describes this:

http://www.codeproject.com/csharp/workerthread.asp

I hope you don't have problems translating of C# code to managed C++. Slightly different syntax:

Thread m_WorkerThread;     // C#
Thread* m_WorkerThread;   // C++
...
0

Featured Post

IT, Stop Being Called Into Every Meeting

Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

Join & Write a Comment

Often, when implementing a feature, you won't know how certain events should be handled at the point where they occur and you'd rather defer to the user of your function or class. For example, a XML parser will extract a tag from the source code, wh…
Basic understanding on "OO- Object Orientation" is needed for designing a logical solution to solve a problem. Basic OOAD is a prerequisite for a coder to ensure that they follow the basic design of OO. This would help developers to understand the b…
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.
The viewer will learn how to clear a vector as well as how to detect empty vectors in C++.

763 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

7 Experts available now in Live!

Get 1:1 Help Now