calling a class when button is clicked

Question

ragoo 0 Newbie Poster

13 Years Ago

hiya, i am new in C++ and need to create a windows form application that at the click of the button the class is called and excecuted. I have done GUI's in java and its no big issue for me, its just that I need the GUI in c++ since the class files are in c++, I have tried looking at JNI's but it can get too complicated.

Any help would be greatly appreciated

c++

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Latest Post 13 Years Ago Latest Post by ragoo

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Ancient Dragon 5,243 Achieved Level 70

13 Years Ago

In Forms designer, double click on the button and the IDE will generate an OnClick event handler. Then just add the code shown below.

#include "Form2.h"
<snip>
    private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
                 Form2^ form2 = gcnew Form2;
                 form2->Show();
             }

Edited 13 Years Ago by Ancient Dragon because: n/a

Ancient Dragon 5,243 Achieved Level 70

13 Years Ago

You stated you wanted to open another form when you pressed a button. Form2.h contains that form. Each form is in another class. Change Form2 to whatever you named the form you want to display when the button is clicked.

Ancient Dragon 5,243 Achieved Level 70

13 Years Ago

>> Form2^ form2 = gcnew form2;

Watch the capitalization. Should be Form2^ form2 = gcnew Form2; Move line 1 down below that #pragma once to let the compiler's preprocessor be more efficient.

Edited 13 Years Ago by Ancient Dragon because: n/a

kirennian 0 Light Poster

13 Years Ago

Thanks for that. I get an error when I compile.

He just said 'Form2' as an example name for the new form you want to open.

Goto Project->Add Class->Windows Form. In there, call it what you wish and the code given should open the new form for you. :)

Ancient Dragon 5,243 Achieved Level 70

13 Years Ago

Repost the current program.

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ragoo 0 Newbie Poster · Answer 1 · 2010-08-03T20:21:09+00:00

This is the code

#pragma once

namespace gui {

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

    protected:
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        ~Form1()
        {
            if (components)
            {
                delete components;
            }
        }
    private: System::Windows::Forms::Button^  button1;
    protected: 

    private:
        /// <summary>
        /// Required designer variable.
        /// </summary>
        System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        void InitializeComponent(void)
        {
        this->button1 = (gcnew System::Windows::Forms::Button());
        this->SuspendLayout();
        // 
        // button1
        // 
        this->button1->Location = System::Drawing::Point(51, 202);
        this->button1->Name = L"button1";
        this->button1->Size = System::Drawing::Size(75, 23);
        this->button1->TabIndex = 0;
        this->button1->Text = L"button1";
        this->button1->UseVisualStyleBackColor = true;
        // 
        // Form1
        // 
        this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
        this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
        this->ClientSize = System::Drawing::Size(292, 273);
        this->Controls->Add(this->button1);
        this->Name = L"Form1";
        this->Text = L"Form1";
        this->ResumeLayout(false);

            }




#pragma endregion
    };
}

ragoo 0 Newbie Poster · Answer 2 · 2010-08-03T20:22:30+00:00

sorry

#pragma once

namespace gui {

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

	protected:
		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		~Form1()
		{
			if (components)
			{
				delete components;
			}
		}
	private: System::Windows::Forms::Button^  button1;
	protected: 

	private:
		/// <summary>
		/// Required designer variable.
		/// </summary>
		System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		void InitializeComponent(void)
		{
		this->button1 = (gcnew System::Windows::Forms::Button());
		this->SuspendLayout();
		// 
		// button1
		// 
		this->button1->Location = System::Drawing::Point(51, 202);
		this->button1->Name = L"button1";
		this->button1->Size = System::Drawing::Size(75, 23);
		this->button1->TabIndex = 0;
		this->button1->Text = L"button1";
		this->button1->UseVisualStyleBackColor = true;
		// 
		// Form1
		// 
		this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
		this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
		this->ClientSize = System::Drawing::Size(292, 273);
		this->Controls->Add(this->button1);
		this->Name = L"Form1";
		this->Text = L"Form1";
		this->ResumeLayout(false);

			}

	
		

#pragma endregion
	};
}

ragoo 0 Newbie Poster · Answer 3 · 2010-08-03T21:04:48+00:00

thanks you for the reply. Forgive me for asking this question, what is contained in the form2.h, since the compiler will ask me where is form2.h defined

Thanks

ragoo 0 Newbie Poster · Answer 4 · 2010-08-03T21:50:43+00:00

Thanks for that. I get an error when I compile.

Error	1	error C2065: 'Form2' : undeclared identifier	
Error	2	error C2065: 'form2' : undeclared identifier	
Error	3	error C2061: syntax error : identifier 'form2'	
Error	4	error C2065: 'Form2' : undeclared identifier	
Error	5	error C2227: left of '->Show' must point to class/struct/union/generic type

ragoo 0 Newbie Poster · Answer 5 · 2010-08-03T21:53:32+00:00

This is the code

#include "Form2.h"

#pragma once

namespace gui {

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

	protected:
		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		~Form1()
		{
			if (components)
			{
				delete components;
			}
		}
	private: System::Windows::Forms::Button^  button1;
	protected: 

	private:
		/// <summary>
		/// Required designer variable.
		/// </summary>
		System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		void InitializeComponent(void)
		{
		this->button1 = (gcnew System::Windows::Forms::Button());
		this->SuspendLayout();
		// 
		// button1
		// 
		this->button1->Location = System::Drawing::Point(39, 170);
		this->button1->Name = L"button1";
		this->button1->Size = System::Drawing::Size(75, 23);
		this->button1->TabIndex = 0;
		this->button1->Text = L"button1";
		this->button1->UseVisualStyleBackColor = true;
		this->button1->Click += gcnew System::EventHandler(this, &Form1::button1_Click);
		// 
		// Form1
		// 
		this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
		this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
		this->ClientSize = System::Drawing::Size(292, 273);
		this->Controls->Add(this->button1);
		this->Name = L"Form1";
		this->Text = L"Form1";
		this->Load += gcnew System::EventHandler(this, &Form1::Form1_Load);
		this->ResumeLayout(false);

			}
#pragma endregion
	private: System::Void Form1_Load(System::Object^  sender, System::EventArgs^  e) {
				 }
	private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
				 Form2^ form2 = gcnew form2;               
				 Form2->Show();
				 }
		};
}

ragoo 0 Newbie Poster · Answer 6 · 2010-08-04T13:39:48+00:00

Thanks for that but it still shows

Error	1	error C2065: 'Form2' : undeclared identifier	86
Error	2	error C2065: 'form2' : undeclared identifier		86
Error	3	error C2061: syntax error : identifier 'Form2'	86
Error	4	error C2065: 'Form2' : undeclared identifier	87
Error	5	error C2227: left of '->Show' must point to class/struct/union/generic type	87

ragoo 0 Newbie Poster · Answer 7 · 2010-08-09T20:22:32+00:00

ragoo 0 Newbie Poster

13 Years Ago

anyone????

ragoo 0 Newbie Poster · Answer 8 · 2010-08-27T13:48:11+00:00

Repost the current program.

#pragma once

#include "HelloWorld.h"


namespace Trial {

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

	protected:
		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		~Form1()
		{
			if (components)
			{
				delete components;
			}
		}
	private: System::Windows::Forms::Button^  button1;
	protected: 

	private:
		/// <summary>
		/// Required designer variable.
		/// </summary>
		System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		void InitializeComponent(void)
		{
			this->button1 = (gcnew System::Windows::Forms::Button());
			this->SuspendLayout();
			// 
			// button1
			// 
			this->button1->Location = System::Drawing::Point(44, 195);
			this->button1->Name = L"button1";
			this->button1->Size = System::Drawing::Size(75, 23);
			this->button1->TabIndex = 0;
			this->button1->Text = L"button1";
			this->button1->UseVisualStyleBackColor = true;
			this->button1->Click += gcnew System::EventHandler(this, &Form1::button1_Click);
			// 
			// Form1
			// 
			this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
			this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
			this->ClientSize = System::Drawing::Size(292, 273);
			this->Controls->Add(this->button1);
			this->Name = L"Form1";
			this->Text = L"Form1";
			this->ResumeLayout(false);

		}
#pragma endregion
	
	private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) {

         App app; // Create a instance of App

         HelloWorld^ form2 = gcnew HelloWorld;           
		 
		 form2->Show();
       }

	};
}

ragoo 0 Newbie Poster · Answer 9 · 2010-08-27T13:49:34+00:00

Apologises for the late reply

This is in the HelloWorld.h

#include <iostream> 

using namespace std; // use std namespace for cout 

ref class App // change name to app
{
public:
 App() // say hello when object is constructed
 {
  Say("IO!");
 };
 ~App() // say goodbye when object is destroyed
 {
  Say("File!");
 };
 void Say(char* Message)
 {
  cout << Message << endl;
 };

 char* Show(char* Message)
 {
   return Message;
 }
};

ragoo 0 Newbie Poster · Answer 10 · 2010-08-27T13:50:01+00:00

ragoo 0 Newbie Poster

13 Years Ago

the above code is my modified version

ragoo 0 Newbie Poster · Answer 11 · 2010-08-27T14:00:16+00:00

These are the Errors

Error	1	error C2065: 'HelloWorld' : undeclared identifier		86
Error	2	error C2065: 'form2' : undeclared identifier		86
Error	3	error C2061: syntax error : identifier 'Form2'		86
Error	4	error C2065: 'form2' : undeclared identifier		88
Error	5	error C2227: left of '->Show' must point to  class/struct/union/generic type		88

ragoo 0 Newbie Poster · Answer 12 · 2010-08-27T15:44:47+00:00

New error

Error	1	error C2065: 'HelloWorld' : undeclared identifier		93
Error	2	error C2065: 'form2' : undeclared identifier		93
Error	3	error C2061: syntax error : identifier 'HelloWorld'		93
Error	4	error C2065: 'form2' : undeclared identifier		94
Error	5	error C2227: left of '->Show' must point to class/struct/union/generic type

calling a class when button is clicked

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