当webview大于屏幕时,将UIWebview内容转换为UIImage

Question

非常类似于这个问题(也是这个答案),我试图从webview中取出UIImage.到目前为止,我正在使用答案中建议的代码,具体来说:

UIGraphicsBeginImageContext(webview.bounds.size);
[webview.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

但是,当webview的内容大于屏幕时,生成的图像不完整且缺少补丁.有想法该怎么解决这个吗？

Answer 1

我得到了答案:

您必须在创建图像之前将Webview的框架设置为完整的内容大小.在此之后,只需将尺寸设置回原点:

+ (UIImage *) imageFromWebView:(UIWebView *)view
{
    // tempframe to reset view size after image was created
    CGRect tmpFrame         = view.frame;

    // set new Frame
    CGRect aFrame               = view.frame;
    aFrame.size.height  = [view sizeThatFits:[[UIScreen mainScreen] bounds].size].height;
    view.frame              = aFrame;

    // do image magic
    UIGraphicsBeginImageContext([view sizeThatFits:[[UIScreen mainScreen] bounds].size]);

    CGContextRef resizedContext = UIGraphicsGetCurrentContext();
    [view.layer renderInContext:resizedContext];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    // reset Frame of view to origin
    view.frame = tmpFrame;
    return image;
}

Answer 2

DR的答案很好.唯一缺少的是考虑到屏幕的规模.我已经在我的Swift版本中更正了它,它对我来说很好.

extension UIWebView{
func snapshotForCompletePage() -> UIImage {
    // tempframe to reset view size after image was created
    let tmpFrame: CGRect = self.frame
    // set full size Frame
    var fullSizeFrame: CGRect = self.frame
    fullSizeFrame.size.height = self.scrollView.contentSize.height
    self.frame = fullSizeFrame

    // here the image magic begins
    UIGraphicsBeginImageContextWithOptions(fullSizeFrame.size, false, UIScreen.mainScreen().scale)
    let resizedContext: CGContextRef = UIGraphicsGetCurrentContext()!
    self.layer.renderInContext(resizedContext)
    let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    // reset Frame of view to origin
    self.frame = tmpFrame
    return image
      }
    }