我正在Visual C中编写一个浏览器助手对象,需要对渲染的网页进行全长截图.目前,我正在我的BHO中捕获DocumentComplete事件.我得到了浏览器的hWnd,并且可以截取它的截图,但这不是我真正需要的.我真的需要渲染页面的窗口(不是带滚动条的框架).
此外,我正在遇到一种竞争条件,当我拍摄屏幕截图时,浏览器可能还没有渲染页面.我已经添加了对UpdateWindow的调用,但即使在返回true之后,有时窗口还没有呈现.
所以,总结一下:
1)如何获取渲染的HTML窗口的hWnd
2)BHO可以截取屏幕截图的适当事件是什么?
编辑:
基于以下答案,我创建了这段代码:
MSHTML::IHTMLRectPtr pRect2 = pBody2->getBoundingClientRect();
long width = pRect2->right;
long height = pRect2->bottom;
RECTL imageRect = { 0, 0, width, height };
IViewObject *pViewObject = NULL;
pHtmlDocument2->QueryInterface(IID_IViewObject, (void**)&pViewObject);
HDC hdcScreen = GetDC(NULL);
HDC hCompDc = CreateCompatibleDC(hdcScreen);
pViewObject->Draw(DVASPECT_CONTENT, -1, NULL, NULL, NULL, hCompDc, NULL, &imageRect, NULL, 0);
HBITMAP hbmp = CreateCompatibleBitmap(hCompDc, imageRect.right - imageRect.left, imageRect.bottom - imageRect.top);
SelectObject(hCompDc, hbmp);
Bitmap *image = new Bitmap(hbmp, NULL);
long bitLength = (imageRect.right - imageRect.left) * (imageRect.bottom - imageRect.top) * 4;
byte *bits = (byte*)malloc(bitLength);
memset(bits, 0, bitLength);
BITMAPINFO *info = new BITMAPINFO();
GetDIBits(hCompDc, hbmp, 0, imageRect.bottom - imageRect.top, bits, info, DIB_RGB_COLORS);
FILE* file = fopen("d:\\screenshot.bmp", "wb");
fwrite(bits, 1, bitLength, file);
fclose(file);
不幸的是,输出不是有效的位图.我不知道我做错了什么.请帮忙.
最佳答案 我假设你有IWebBrowser2接口,对吧?
然后我会得到一个HTML文档的接口:
HRESULT IWebBrowser2::get_Document(IDispatch **ppDisp);
然后到视图(as suggested here),在提供的DC上绘制内容:
//hCompDc is a CompatibleDC which select a CompatibleBitmap.
RECTL imageRect = {0, 0, nWidth, nHeight};
pHtmlDocument2->QueryInterface(IID_IViewObject, (void **)&pViewObject);
pViewObject->Draw(DVASPECT_CONTENT, -1, NULL, NULL, NULL,
hCompDc, NULL, &imageRect, NULL, 0);