Convert UIWebview contents to a UIImage when the webview is larger than the screen

问题

Very similar to this question (and also this answer), I'm trying to make an UIImage out from a webview. So far I'm using the code suggested in the answer, specifically:

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

However, when the contents of the webview are larger than the screen, the resulting images are not complete and have missing patches. Any ideas on how to fix this?

回答1:

I got the answer:

You have to set the frame of the Webview to the full content size just before you create the image. After this just set the size back to origin:

+ (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;
}

回答2:

D R's answer is fine. The only thing missing is taking into account the scale of screen. I have it corrected in my Swift version and it works fine for me.

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
      }
    }

回答3:

@Jibeex's answer worked for me. But I had to add the following code

    fullSizeFrame.size.width = self.scrollView.contentSize.width

below

    fullSizeFrame.size.height = self.scrollView.contentSize.height

for it to fully work. Writing as answer because I don't have enough reputation to comment.

回答4:

I think this could help

UIGraphicsBeginImageContext([webView sizeThatFits:[[UIScreen mainScreen] bounds].size]]);

来源：https://stackoverflow.com/questions/4475397/convert-uiwebview-contents-to-a-uiimage-when-the-webview-is-larger-than-the-scre

标签

iphone

objective-c

ios

uiwebview

uiimage