Bitmap change on button press..

[Code_Nerd]

I wrote this as a lead up to something I need to develop further down the track..
All I want to do at the moment is change the bitmap image when the button is pressed!

It is not working this way, and I am stuck for ideas ATM!
Can anyone tell me why it is not working correctly..

Cheers

#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <commctrl.h>
#include <iostream>
#include "Resource.h"

using namespace std;

#pragma comment(lib, "comctl32.lib")


INT_PTR CALLBACK DlgProc( HWND hwnd , UINT msg , WPARAM wparam , LPARAM lparam)
{
	HWND Pic  = GetDlgItem(hwnd, IDC_GREEN);
	HWND Button = GetDlgItem(hwnd, IDC_BUTTON1);
	
	switch(msg)
	{
	case WM_INITDIALOG:
		{
			static HBITMAP hbmp;
	
			hbmp = (HBITMAP)LoadImage(0, MAKEINTRESOURCE(IDB_GREEN), IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
			SendMessage(Pic, BM_SETIMAGE, IDC_GREEN, (LPARAM)hbmp);
			SendMessage(hwnd, WM_SETICON, ICON_SMALL, (LPARAM)LoadIcon(GetModuleHandle(0), MAKEINTRESOURCE(0)));
		}
	break;

	case WM_COMMAND:
		switch(HIWORD(wparam))
		{
			case BN_CLICKED:
					if(LOWORD(wparam) == IDC_BUTTON1)
					{
						//MessageBox(hwnd, "check for Message", 0 ,0);
						static HBITMAP hbmp = (HBITMAP)LoadImage(0, MAKEINTRESOURCE(IDB_RED), IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE | LR_LOADTRANSPARENT);	
						SendMessage(Pic, BM_SETIMAGE, IDC_GREEN, (LPARAM)hbmp);
					}
			break;
		}
	break;
		
	case WM_CLOSE:
		{
			PostQuitMessage(0);
		}
	break;		
			
	}
	return false;
}

INT WINAPI WinMain(HINSTANCE hinstance, HINSTANCE hprevinstance,
    LPSTR lpcmdline, int ncmdshow)
{
	
	InitCommonControls();
	
	DialogBox(hinstance, MAKEINTRESOURCE(IDD_MAIN), 0, DlgProc);
        
    return 0;
}

[sucur]

On first look I think your SendMessage function isn't good, exactly 3rd parameter is IMAGE_BITMAP (WPARAM), not IDC_GREEN.

[Code_Nerd]

I always thought IMAGE_BITMAP is of UINT type??

If I put IMAGE_BITMAP in it still does not function correctly?

[golanshahar]

I always thought IMAGE_BITMAP is of UINT type??

And how is that related to the fact you are passing the wrong ID?

If I put IMAGE_BITMAP in it still does not function correctly?

Did you set the SS_BITMAP style to your pic control?

Cheers

[Code_Nerd]

I am very new to WIN32 programming..

I am not sure where I am meant to set SS_BITMAP?

Thankyou

[golanshahar]

• Go to the resource editor
• Right click on the image ( static ) control
• Choose properties
• In the type combo box choose Bitmap

Cheers

[Boris K K]

Also, if IDB_RED and IDB_GREEN are resources, you should:

1. Pass a valid hInstance as a first parameter to LoadImage
2. Do not specify LR_LOADFROMFILE flag

[Code_Nerd]

OK I think I have passed the correct hInstance to LoadImage() and now it seems as if the bitmap is loading correctly and getting put into hbmp..

@ golanshahar the picture control was already set as Bitmap type in the resource editor.. Thankyou

My code now looks like this:

#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <commctrl.h>
#include <iostream>
#include <stdlib.h>
#include "Resource.h"

using namespace std;

#pragma comment(lib, "comctl32.lib")


INT_PTR CALLBACK DlgProc( HWND hwnd , UINT msg , WPARAM wparam , LPARAM lparam)
{
	HWND Pic  = GetDlgItem(hwnd, IDC_GREEN);
	HWND Button = GetDlgItem(hwnd, IDC_BUTTON1);
	
	switch(msg)
	{
	case WM_INITDIALOG:
		{
			static HBITMAP hbmp;
	
			hbmp = (HBITMAP)LoadImage(GetModuleHandle(0), MAKEINTRESOURCE(IDB_GREEN), IMAGE_BITMAP, 0, 0, 0);
			if(!hbmp)
			{
				MessageBox(hwnd, "Test if no bitmap loaded", 0 ,0);
			}
			DWORD dw = GetLastError();
			char poop[123]; itoa(dw, poop, 100);
			MessageBox(hwnd, poop, 0 ,0);
			SendMessage(Pic, BM_SETIMAGE, IDC_GREEN, (LPARAM)hbmp);
			SendMessage(hwnd, WM_SETICON, ICON_SMALL, (LPARAM)LoadIcon(GetModuleHandle(0), MAKEINTRESOURCE(0)));
		}
	break;

	case WM_COMMAND:
		switch(HIWORD(wparam))
		{
			case BN_CLICKED:
					if(LOWORD(wparam) == IDC_BUTTON1)
					{
						
						static HBITMAP hbmp = (HBITMAP)LoadImage(GetModuleHandle(0), MAKEINTRESOURCE(IDB_RED), IMAGE_BITMAP, 0, 0, 0);	
						if(!hbmp)
							MessageBox(hwnd, "check for Message", 0 ,0);
						else
							SendMessage(Pic, BM_SETIMAGE, IDC_GREEN, (LPARAM)hbmp);
						DWORD dw = GetLastError();
						char poop[123]; itoa(dw, poop, 100);
						MessageBox(hwnd, poop, 0 ,0);
					}
			break;
		}
	break;
		
	case WM_CLOSE:
		{
			PostQuitMessage(0);
		}
	break;		
			
	}
	return false;
}

INT WINAPI WinMain(HINSTANCE hinstance, HINSTANCE hprevinstance,
    LPSTR lpcmdline, int ncmdshow)
{
	
	InitCommonControls();
	
	DialogBox(hinstance, MAKEINTRESOURCE(IDD_MAIN), 0, DlgProc);
        
    return 0;
}

[golanshahar]

Your code still incorrect, instead of:

::SendMessage(Pic, BM_SETIMAGE, IDC_GREEN, (LPARAM)hbmp);

It should be:

::SendMessage(Pic, BM_SETIMAGE, IMAGE_BITMAP, (LPARAM)hbmp);

Read the documentation of BM_SETIMAGE.

Cheers

[Code_Nerd]

Thankyou for your reply...
I understand where I went wrong now, however the image is still not changing with the button press?

What else could it possibly be? Do I have to create a special type of bitmap (8bit etc etc) I am trying to use 24 bit .bmps...

Thanks again..

[golanshahar]

Look at this thread for sample.

Cheers