Seeking for Volunteer C++ Windows Form Application Tutor



Currently, I am doing small application for my Master Degree project, I have done small part on my program using Win32 C++ Console, But now I need to migrate my code into Windows Form Application (GUI) which has to be written in C++ as well so that it look more user friendly.

I am using Microsoft Visual Studio 2008 with .NET Framework 2.0. OpenCV 1.1 as additional external library.

Currently, I face trouble with the coding. I am not so sure how I can integrate my program with GUI or Windows Form Applications. When looking into some example code, it seem that I have to add in Thread Class. What is that and how i can use it? "Delegate" what is all this. I never learn all this during my Bachelor course.




I tried this simple program like if we click the button2, the "Title" Text will change to "ABC". But when I try to build with the code below, it crashed.

#pragma once
#include "highgui.h"
#include "cv.h"
#include "numExpression.h"



#define NUM "Global"

namespace TestApp {

using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;

///

/// Summary for Form1
///
/// WARNING: If you change the name of this class, you will need to change the
/// 'Resource File Name' property for the managed resource compiler tool
/// associated with all .resx files this class depends on. Otherwise,
/// the designers will not be able to interact properly with localized
/// resources associated with this form.
///

public ref class Form1 : public System::Windows::Forms::Form
{
public:
Form1(void)
{
InitializeComponent();
//
//TODO: Add the constructor code here
//
}

protected:
///

/// Clean up any resources being used.
///

~Form1()
{
if (components)
{
delete components;
}
}

private: System::Windows::Forms::Label^ label1;
private: System::Windows::Forms::Button^ button1;
private: System::Windows::Forms::TextBox^ textBox1;
private: System::Windows::Forms::Button^ button2;
private: System::Threading::Thread^ trd;

protected:

private:
///

/// Required designer variable.
///

System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
///

/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
///

void InitializeComponent(void)
{
this->label1 = (gcnew System::Windows::Forms::Label());
this->button1 = (gcnew System::Windows::Forms::Button());
this->textBox1 = (gcnew System::Windows::Forms::TextBox());
this->button2 = (gcnew System::Windows::Forms::Button());
this->SuspendLayout();
//
// label1
//
this->label1->AutoSize = true;
this->label1->Location = System::Drawing::Point(255, 37);
this->label1->Name = L"label1";
this->label1->RightToLeft = System::Windows::Forms::RightToLeft::No;
this->label1->Size = System::Drawing::Size(27, 13);
this->label1->TabIndex = 0;
this->label1->Text = L"Title";
this->label1->TextAlign = System::Drawing::ContentAlignment::TopCenter;
//
// button1
//
this->button1->Location = System::Drawing::Point(12, 282);
this->button1->Name = L"button1";
this->button1->Size = System::Drawing::Size(75, 23);
this->button1->TabIndex = 1;
this->button1->Text = L"button1";
this->button1->UseVisualStyleBackColor = true;
this->button1->Click += gcnew System::EventHandler(this, &Form1::button1_Click);
//
// textBox1
//
this->textBox1->Location = System::Drawing::Point(156, 65);
this->textBox1->Name = L"textBox1";
this->textBox1->Size = System::Drawing::Size(191, 20);
this->textBox1->TabIndex = 2;
//
// button2
//
this->button2->Location = System::Drawing::Point(272, 282);
this->button2->Name = L"button2";
this->button2->Size = System::Drawing::Size(75, 23);
this->button2->TabIndex = 3;
this->button2->Text = L"button2";
this->button2->UseVisualStyleBackColor = true;
this->button2->Click += gcnew System::EventHandler(this, &Form1::button2_Click);
//
// Form1
//
this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
this->ClientSize = System::Drawing::Size(359, 317);
this->Controls->Add(this->button2);
this->Controls->Add(this->textBox1);
this->Controls->Add(this->button1);
this->Controls->Add(this->label1);
this->Name = L"Form1";
this->Text = L"TestApp";
this->Load += gcnew System::EventHandler(this, &Form1::Form1_Load);
this->ResumeLayout(false);
this->PerformLayout();

}
#pragma endregion

private: void testF()
{
/* for(int i = 0; i < 10; i++)
MessageBox::Show("Loop number " + i);*/
label1->Text = "ABC";
}

private: System::Void button2_Click(System::Object^ sender, System::EventArgs^ e) {
trd = gcnew System::Threading::Thread (gcnew System::Threading::ThreadStart (this, &Form1::testF));
trd->Start();
}
private: System::Void Form1_Load(System::Object^ sender, System::EventArgs^ e) {


}
};
}

Crash Error Message :
An unhandled exception of type 'System.InvalidOperationException' occurred in System.Windows.Forms.dll

Additional information: Cross-thread operation not valid: Control 'label1' accessed from a thread other than the thread it was created on.

Anyone could help me?

Hey so no one provided help? I would like to know how to integrate my OpenCV code in console application with my windows form application

Hi,

you are using Microsoft Visual Studio C++?
if you are then you have to create the Project File using Windows Form Application, then from there, it gives you Form.h for the first file.

Then you can start from there...