Save the screenshot, define a separate screenshot header file (wxpCapture)
//==============================================================================
//
// Title: wxpCapture.h
// Purpose: A short description of the interface.
//
// Created on: 2021-1-21 at 10:09:07 by xt256.com.
// Copyright: xt256.com. All Rights Reserved.
//
//==============================================================================
#ifndef __wxpCapture_H__
#define __wxpCapture_H__
#ifdef __cplusplus
extern "C" {
#endif
//==============================================================================
#include "cvidef.h"
#include "stdio.h"
#include "windows.h"
//=============================================================================
HBITMAP GetCaptureBmp(int panelID)
{
//获取面板的左上角坐标、宽度和高度
int xLeft=0;
int yTop=0;
int xWidth=0;
int yHeight=0;
GetPanelAttribute(panelID, ATTR_LEFT, &xLeft);
GetPanelAttribute(panelID, ATTR_TOP, &yTop);
GetPanelAttribute(panelID, ATTR_WIDTH, &xWidth);
GetPanelAttribute(panelID, ATTR_HEIGHT, &yHeight);
//修正高度,本身没有包含标题栏,加35后包含标题栏
yTop-=35;
yHeight+=35;
HDC hDC;
HDC MemDC;
BYTE* Data;
HBITMAP hBmp;
BITMAPINFO bi;
memset(&bi, 0, sizeof(bi));
bi.bmiHeader.biSize = sizeof(BITMAPINFO);
bi.bmiHeader.biWidth = xWidth;// GetSystemMetrics(SM_CXSCREEN)-500;
bi.bmiHeader.biHeight =yHeight;// GetSystemMetrics(SM_CYSCREEN)-500;
bi.bmiHeader.biPlanes = 1;
bi.bmiHeader.biBitCount = 24;
hDC = GetDC(NULL);
MemDC = CreateCompatibleDC(hDC);
hBmp = CreateDIBSection(MemDC, &bi, DIB_RGB_COLORS, (void**)&Data, NULL, 0);
SelectObject(MemDC, hBmp); //起点位置
BitBlt(MemDC, 0, 0,bi.bmiHeader.biWidth,bi.bmiHeader.biHeight,hDC,xLeft,yTop,SRCCOPY);
ReleaseDC(NULL, hDC);
DeleteDC(MemDC);
return hBmp;
}
/************************************************************************/
/* hBitmap 为刚才的屏幕位图句柄
/* lpFileName 为须要保存的位图文件名称
/************************************************************************/
int SaveBitmapToFile(int winID,LPSTR lpFileName)
{
HBITMAP hBitmap;
hBitmap = GetCaptureBmp(winID);
HDC hDC; //设备描写叙述表
int iBits; //当前显示分辨率下每一个像素所占字节数
WORD wBitCount=1; //位图中每一个像素所占字节数
DWORD dwPaletteSize=0; //定义调色板大小
DWORD dwBmBitsSize; //位图中像素字节大小
DWORD dwDIBSize; //位图文件大小
DWORD dwWritten; //写入文件字节数
BITMAP Bitmap; //位图结构
BITMAPFILEHEADER bmfHdr; //位图属性结构
BITMAPINFOHEADER bi; //位图文件头结构
LPBITMAPINFOHEADER lpbi; //位图信息头结构 指向位图信息头结构
HANDLE fh; //定义文件句柄
HANDLE hDib; //分配内存句柄
HANDLE hPal; //分配内存句柄
HANDLE hOldPal=NULL; //调色板句柄
//计算位图文件每一个像素所占字节数
hDC=GetDC((HWND)winID);
iBits = 24;
ReleaseDC((HWND)winID,hDC);
if (iBits <= 1)
wBitCount = 1;
else if (iBits <= 4)
wBitCount = 4;
else if (iBits <= 8)
wBitCount = 8;
else if (iBits <= 24)
wBitCount = 24;
else if (iBits<=32)
wBitCount = 24;
//计算调色板大小
if (wBitCount <= 8)
dwPaletteSize = (1 << wBitCount) *sizeof(RGBQUAD);
//设置位图信息头结构
GetObject(hBitmap, sizeof(BITMAP), (LPSTR)&Bitmap);
bi.biSize = sizeof(BITMAPINFOHEADER);
bi.biWidth = Bitmap.bmWidth;
bi.biHeight = Bitmap.bmHeight;
bi.biPlanes = 1;
bi.biBitCount = wBitCount;
bi.biCompression = BI_RGB;
bi.biSizeImage = 0;
bi.biXPelsPerMeter =0;
bi.biYPelsPerMeter =0;
bi.biClrUsed = 0;
bi.biClrImportant = 0;
dwBmBitsSize = ((Bitmap.bmWidth *wBitCount+31)/32)* 4*Bitmap.bmHeight ;
//为位图内容分配内存
hDib = GlobalAlloc(GHND,dwBmBitsSize+dwPaletteSize+sizeof(BITMAPINFOHEADER));
lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib);
if (lpbi==NULL)
{
return 0;
}
*lpbi = bi;
// 处理调色板
hPal = GetStockObject(DEFAULT_PALETTE);
if (hPal)
{
hDC = GetDC(NULL);
hOldPal = SelectPalette(hDC, (HPALETTE)hPal, FALSE);
RealizePalette(hDC);
}
// 获取该调色板下新的像素值
GetDIBits(hDC, hBitmap, 0, (UINT) Bitmap.bmHeight,
(LPSTR)lpbi + sizeof(BITMAPINFOHEADER)+dwPaletteSize,
(LPBITMAPINFO)lpbi, DIB_RGB_COLORS);
//恢复调色板
if (hOldPal)
{
SelectPalette(hDC, (HPALETTE)hOldPal, TRUE);
RealizePalette(hDC);
ReleaseDC(NULL, hDC);
}
//创建位图文件
fh = CreateFile(lpFileName, GENERIC_WRITE,
0, NULL, CREATE_ALWAYS,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);
if (fh == INVALID_HANDLE_VALUE)
return FALSE;
// 设置位图文件头
bmfHdr.bfType = 0x4D42; // "BM"
dwDIBSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER)+ dwPaletteSize + dwBmBitsSize;
bmfHdr.bfSize = dwDIBSize;
bmfHdr.bfReserved1 = 0;
bmfHdr.bfReserved2 = 0;
bmfHdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER) + (DWORD)sizeof(BITMAPINFOHEADER)+ dwPaletteSize;
// 写入位图文件头
WriteFile(fh, (LPSTR)&bmfHdr, sizeof(BITMAPFILEHEADER), &dwWritten, NULL);
// 写入位图文件其余内容
WriteFile(fh, (LPSTR)lpbi, dwDIBSize, &dwWritten, NULL);
//清除
GlobalUnlock(hDib);
GlobalFree(hDib);
CloseHandle(fh);
return 1;
}
#ifdef __cplusplus
}
#endif
#endif /* ndef __wxpCapture_H__ */
Call example
#include "capturePic.h"
#include "wxpCapture.h"
#include <utility.h>
static int panelHandle;
int CVICALLBACK capturePic (int panel, int control, int event,
void *callbackData, int eventData1, int eventData2)
{
char filePath[500];
switch (event)
{
case EVENT_COMMIT:
FileSelectPopup ("c:\\Users\\Administrator\\Desktop", "*.bmp", "", "", VAL_SAVE_BUTTON, 0, 0, 1, 1, filePath);
SetWaitCursor(1);
Delay(0.1);
SaveBitmapToFile(panelHandle,filePath);
MessagePopup("提示","截图完成");
SetWaitCursor(0);
break;
}
return 0;
}