iphone - 获取网页图像

我正在尝试捕获网页的完整图像。
但是它显示空白图像。

我应该怎么做才能获得完整的网页图像？

我尝试过

CGSize overallSize = [WebPageImage sizeThatFits:CGSizeZero];
UIGraphicsBeginImageContext(WebPageImage.scrollView.contentSize);
WebPageImage.bounds = CGRectMake(0, 0, overallSize.width, overallSize.height);
while (WebPageImage.loading) {
    [NSThread sleepForTimeInterval:0.1];
}
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,(unsigned long)NULL), ^(void) {
    UIImageWriteToSavedPhotosAlbum(viewImage, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
});

请提出一些解决方案..
WebPageImage是UIWebView。

最佳答案

UIGraphicsBeginImageContextWithOptions(WebPageImage.bounds.size, WebPageImage.opaque, 0.0);
[WebPageImage.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();