Qt5调用QPixmap::fromWinHICON

Posted 2023-01-20 imxiangzi

QPixmap QPixmap::fromWinHICON ( HICON icon )  [static]

Win32 only: Returns a QPixmap  that is equivalent to the given icon.
Warning:This function is only available on Windows.
This function was introduced in Qt 4.6.

在5.2里面直接没有这个方法了,真是让人捉急.

去Qt4.7源码里翻了翻找到了 fromWinHICON的实现:

qt-everywhere-opensource-src-4.7.0\\src\\gui\\image\\qpixmap_win.cpp  line:283

其中引用到的函数 qMalloc() 在

qt-everywhere-opensource-src-4.7.0\\src\\corelib\\global\\qmalloc.cpp line:53

相关功能全部代码:

void *qMalloc(size_t size)

return ::malloc(size);

void qFree(void *ptr)

::free(ptr);

static QImage qt_fromWinHBITMAP(HDC hdc, HBITMAP bitmap, int w, int h)

BITMAPINFO bmi;

memset(&bmi, 0, sizeof(bmi));

bmi.bmiHeader.biSize        = sizeof(BITMAPINFOHEADER);

bmi.bmiHeader.biWidth       = w;

bmi.bmiHeader.biHeight      = -h;

bmi.bmiHeader.biPlanes      = 1;

bmi.bmiHeader.biBitCount    = 32;

bmi.bmiHeader.biCompression = BI_RGB;

bmi.bmiHeader.biSizeImage   = w * h * 4;

QImage image(w, h, QImage::Format_ARGB32_Premultiplied);

if (image.isNull())

return image;

// Get bitmap bits

uchar *data = (uchar *) qMalloc(bmi.bmiHeader.biSizeImage);

if (GetDIBits(hdc, bitmap, 0, h, data, &bmi, DIB_RGB_COLORS))

// Create image and copy data into image.

for (int y=0; y<h; ++y)

void *dest = (void *) image.scanLine(y);

void *src = data + y * image.bytesPerLine();

memcpy(dest, src, image.bytesPerLine());

else

qWarning("qt_fromWinHBITMAP(), failed to get bitmap bits");

qFree(data);

return image;

QPixmap fromWinHICON(HICON icon)//qt4.7 QPixmap::fromWinHICON(hIcon)

bool foundAlpha = false;

HDC screenDevice = GetDC(0);

HDC hdc = CreateCompatibleDC(screenDevice);

ReleaseDC(0, screenDevice);

ICONINFO iconinfo;

bool result = GetIconInfo(icon, &iconinfo); //x and y Hotspot describes the icon center

if (!result)

qWarning("QPixmap::fromWinHICON(), failed to GetIconInfo()");

int w = iconinfo.xHotspot * 2;

int h = iconinfo.yHotspot * 2;

BITMAPINFOHEADER bitmapInfo;

bitmapInfo.biSize        = sizeof(BITMAPINFOHEADER);

bitmapInfo.biWidth       = w;

bitmapInfo.biHeight      = h;

bitmapInfo.biPlanes      = 1;

bitmapInfo.biBitCount    = 32;

bitmapInfo.biCompression = BI_RGB;

bitmapInfo.biSizeImage   = 0;

bitmapInfo.biXPelsPerMeter = 0;

bitmapInfo.biYPelsPerMeter = 0;

bitmapInfo.biClrUsed       = 0;

bitmapInfo.biClrImportant  = 0;

DWORD* bits;

HBITMAP winBitmap = CreateDIBSection(hdc, (BITMAPINFO*)&bitmapInfo, DIB_RGB_COLORS, (VOID**)&bits, NULL, 0);

HGDIOBJ oldhdc = (HBITMAP)SelectObject(hdc, winBitmap);

DrawIconEx( hdc, 0, 0, icon, iconinfo.xHotspot * 2, iconinfo.yHotspot * 2, 0, 0, DI_NORMAL);

QImage image = qt_fromWinHBITMAP(hdc, winBitmap, w, h);

for (int y = 0 ; y < h && !foundAlpha ; y++)

QRgb *scanLine= reinterpret_cast<QRgb *>(image.scanLine(y));

for (int x = 0; x < w ; x++)

if (qAlpha(scanLine[x]) != 0)

foundAlpha = true;

break;

if (!foundAlpha)

//If no alpha was found, we use the mask to set alpha values

DrawIconEx( hdc, 0, 0, icon, w, h, 0, 0, DI_MASK);

QImage mask = qt_fromWinHBITMAP(hdc, winBitmap, w, h);

for (int y = 0 ; y < h ; y++)

QRgb *scanlineImage = reinterpret_cast<QRgb *>(image.scanLine(y));

QRgb *scanlineMask = mask.isNull() ? 0 : reinterpret_cast<QRgb *>(mask.scanLine(y));

for (int x = 0; x < w ; x++)

if (scanlineMask && qRed(scanlineMask[x]) != 0)

scanlineImage[x] = 0; //mask out this pixel

else

scanlineImage[x] |= 0xff000000; // set the alpha channel to 255

//dispose resources created by iconinfo call

DeleteObject(iconinfo.hbmMask);

DeleteObject(iconinfo.hbmColor);

SelectObject(hdc, oldhdc); //restore state

DeleteObject(winBitmap);

DeleteDC(hdc);

return QPixmap::fromImage(image);

添加到 Qt5.2工程里,编译通过.

关键测试代码:

//add lib for ExtractIcon()

#include <shellapi.h>

#pragma comment(lib,"Shell32.lib")

//使用winAPI获得dll,exe文件内所有图标资源

QString f1=ui->tx_icon->text();

HINSTANCE hInstance = (HINSTANCE)::GetModuleHandle(NULL);

int count;

count = (int)ExtractIconA(hInstance, f1.toLocal8Bit(), -1);

HICON hIcon;

qDebug()<<"totalIcon:"<<count;

QListWidget *list=ui->list_ico;

list->clear();

QPixmap img;

for(int i=0;i<count;i++)

hIcon = ExtractIconA(hInstance, f1.toLocal8Bit(), i);

img=fromWinHICON(hIcon);

list->addItem(new QListWidgetItem(QIcon(img),QString::number(i)));

DestroyIcon(hIcon);

</shellapi.h>

最终效果:

 

FROM: http://www.yurenchen.com/qt_fromWinHICON.htm