imagebrowse.cpp

在窗口里的图像预览

#include "ImageBrowse.h"
#include "cPic.h"
#include "resource.h"


//Forward declarations
BOOL CALLBACK MainDlgProc(HWND, UINT, WPARAM, LPARAM);
BOOL NEAR CALLBACK HandleNotify(HWND , LPOFNOTIFY);
LRESULT CALLBACK ComDlgPreviewProc(HWND , UINT, WPARAM , LPARAM );
BOOL ShowOpenDialogPreview( HWND,TCHAR *);
void CenterScreen(HWND hDlg);
void ShowImagePreview(HWND,char *);

//global hInstance
HINSTANCE g_hInst;
//picture box background brush handle
HBRUSH hbrush;


//WinMain..Program Enty Point
int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance
		    ,LPSTR lpszCmdParam,int nCmdShow)
{
	g_hInst=hInstance; //save this in our global hInstance
    hbrush = CreateSolidBrush(RGB(100,100,100)); //backcolor of picture box

	//Modal Dialog box makes things easier
	DialogBox(g_hInst, MAKEINTRESOURCE(IDD_MAIN_DIALOG), HWND_DESKTOP, MainDlgProc);
	//clean up
	DeleteObject(hbrush);
	return 0;
}

BOOL CALLBACK MainDlgProc(HWND hDlg,UINT iMessage,WPARAM wParam,LPARAM lParam)
{
	TCHAR  szFile[MAX_PATH]      = "\0";
	switch(iMessage)
	{
	case WM_INITDIALOG:
		//Center our Dlg on the Screen
		CenterScreen(hDlg);

		return TRUE;
	case WM_COMMAND:
		switch (LOWORD(wParam))
		{
		case IDOK:
			//Show the Comm Dialog
			if(ShowOpenDialogPreview(hDlg,szFile))
				//if we selected a file than let's show it
				MessageBox(hDlg,szFile,"File Name",MB_OK);
			break;
		case IDCANCEL:
			//Destroy Dlg
			EndDialog(hDlg,0);
			return TRUE;
		}
		return FALSE;
	}
	return FALSE;
}


//Center our Dlg on the Screen
void CenterScreen(HWND hDlg)
{
	HDC tDC =GetDC(NULL);
	RECT rect;
	int w = GetDeviceCaps(tDC,HORZRES);
	int h = GetDeviceCaps(tDC,VERTRES);
	GetWindowRect(hDlg,&rect); //Get the whole window rect
	int ww = rect.right - rect.left ;
	int wh = rect.bottom - rect.top ;
	SetWindowPos(hDlg,HWND_TOP,(w - ww)/2,(h - wh)/2,0,0,SWP_NOSIZE);//do not change dimensions just center screen
	ReleaseDC(NULL,tDC);
}



//Hook function for the Comm Dlg
LRESULT CALLBACK ComDlgPreviewProc(HWND hDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	

	switch (uMsg)
	{
		case WM_INITDIALOG:
			// Save off the long pointer to the OPENFILENAME structure.
			SetWindowLong(hDlg, DWL_USER, lParam);
			break;

		case WM_DESTROY:
			{
			LPOPENFILENAME lpOFN = (LPOPENFILENAME)GetWindowLong(hDlg, DWL_USER);
			
			}
			break;

			//if the check box is checked than we don't need to load the Image
			//just clean the picture box
			case WM_COMMAND:
			if ((HIWORD(wParam) == BN_CLICKED) && (LOWORD(wParam) == IDC_CHECK1))
            {
				if(SendDlgItemMessage(hDlg,IDC_CHECK1,BM_GETCHECK,0,0) == BST_CHECKED)
				{
					InvalidateRect(GetDlgItem(hDlg,IDC_PIC),NULL,FALSE);
					SetDlgItemInt(hDlg,IDC_W,0,FALSE); //width = 0
	                SetDlgItemInt(hDlg,IDC_H,0,FALSE); //height= 0
				}
			}
			break;

			//Sets the Picture box backcolor
			case WM_CTLCOLORSTATIC:
			
			if((HWND)lParam == GetDlgItem(hDlg,IDC_PIC))
		{
			SetBkColor((HDC)wParam,RGB(100,100,100));
			//don't forget to return the Brush handle.
			return (BOOL) hbrush;
		}

			break;

		case WM_NOTIFY:
			//Handles Notify messages
			HandleNotify(hDlg, (LPOFNOTIFY)lParam);
			

		default:
		
			return FALSE;
	}
	return TRUE;
}


//Call back to handle notify messages
BOOL NEAR CALLBACK HandleNotify(HWND hDlg, LPOFNOTIFY pofn)
{
	switch (pofn->hdr.code)
	{
		// The selection has changed. 
		case CDN_SELCHANGE:
		{
			char szFile[MAX_PATH];


			// Get the path of the selected file.
			if (CommDlg_OpenSave_GetFilePath(GetParent(hDlg),
				szFile, sizeof(szFile)) <= sizeof(szFile))
			{
				//if it is a dirctory than we don't care
				if(GetFileAttributes(szFile) !=  FILE_ATTRIBUTE_DIRECTORY)
				{
				
					//Should we load the Pic
				if(SendDlgItemMessage(hDlg,IDC_CHECK1,BM_GETCHECK,0,0) == BST_UNCHECKED)
					//oh yes..go on..
					ShowImagePreview(hDlg,szFile);
				
				}
			}
		}
		
		break;

		case CDN_FILEOK:
		    //return FALSE to close the Comm Dlg
			return FALSE;
			break;

	}

	return(TRUE);
}


//Shows the Comm Dialog
BOOL ShowOpenDialogPreview(HWND hWnd,TCHAR * szFile)
{
    
   
	OPENFILENAME OpenFileName;
	

	// Fill in the OPENFILENAME structure to support a template and hook.
	OpenFileName.lStructSize       = sizeof(OPENFILENAME);
    OpenFileName.hwndOwner         = hWnd;
    OpenFileName.hInstance         = g_hInst;
    OpenFileName.lpstrFilter       = "All supported types\0*.JPG;*.BMP;*.GIF;*.JPE;*.JPEG;*.WMF\0JPEG Images\0*.JPG;*.JPE;*.JPEG\0GIF Images\0*.GIF\0BMP Images\0*.BMP\0\0";
    OpenFileName.lpstrCustomFilter = NULL;
    OpenFileName.nMaxCustFilter    = 0;
    OpenFileName.nFilterIndex      = 0;
    OpenFileName.lpstrFile         = szFile;
    OpenFileName.nMaxFile          = MAX_PATH;
    OpenFileName.lpstrFileTitle    = NULL;
    OpenFileName.nMaxFileTitle     = 0;
    OpenFileName.lpstrInitialDir   = NULL;
    OpenFileName.lpstrTitle        = "Open an Image File";
    OpenFileName.nFileOffset       = 0;
    OpenFileName.nFileExtension    = 0;
    OpenFileName.lpstrDefExt       = NULL;
    OpenFileName.lCustData         = NULL;
	OpenFileName.lpfnHook 		   = (LPOFNHOOKPROC)ComDlgPreviewProc;
	OpenFileName.lpTemplateName    = MAKEINTRESOURCE(IDD_DIALOG_HOOK);
    OpenFileName.Flags             = OFN_EXPLORER | OFN_ENABLEHOOK | OFN_ENABLETEMPLATE |OFN_HIDEREADONLY;

	
	return GetOpenFileName(&OpenFileName);
}


//Loads the Image and draws it in the Picture Box(static control)
void ShowImagePreview(HWND hDlg,char * ImagePath)
{
	RECT rect;
	HDC tDC = GetDC(GetDlgItem(hDlg,IDC_PIC)); //Get the DC for the Picture Box
	GetClientRect(GetDlgItem(hDlg,IDC_PIC),&rect);//Get dimensions of it
	_PICTURE_ pic;
	//Try to load the Image..if not then we should return
	if(!pic.LoadPicture(ImagePath)) return;
	//set the width & height labels
	SetDlgItemInt(hDlg,IDC_W,pic._GetWidth(),FALSE);
	SetDlgItemInt(hDlg,IDC_H,pic._GetHeight(),FALSE);
	//Draw the image in the picture box
	//(could be updated to maintain aspect ratio)
	pic.DrawPicture(tDC,0,0,rect.right - rect.left ,rect.bottom - rect.top );
	ReleaseDC(GetDlgItem(hDlg,IDC_PIC),tDC);
}