I use the code below to save WKWebView into UIImage. But the problem is, more than 50% of the UIImage is blank/white space.
- (UIImage *)screenCapture {
UIImage *image;
UIGraphicsBeginImageContextWithOptions(self.scrollView.contentSize, TRUE, 0.0f);
{
CGPoint savedContentOffset = self.scrollView.contentOffset;
CGRect savedFrame = self.scrollView.frame;
self.scrollView.contentOffset = CGPointZero;
self.scrollView.frame = CGRectMake(0, 0, self.scrollView.contentSize.width, self.scrollView.contentSize.height);
[self.scrollView drawViewHierarchyInRect:self.scrollView.bounds afterScreenUpdates:YES];
image = UIGraphicsGetImageFromCurrentImageContext();
self.scrollView.contentOffset = savedContentOffset;
self.scrollView.frame = savedFrame;
}
UIGraphicsEndImageContext();
return image;
}
Does anyone have encountered the same problem? Any ideas for a workaround here?
I've also tried this: [self.scrollView.layer renderInContext:UIGraphicsGetCurrentContext()]; but it is much worse, the UIImage is just plain white.
UPDATE:
Here's my sample captured UIImage.
Captured UIImage
Try this:
UIGraphicsBeginImageContext(scrollView.frame.size);
[scrollView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Now you have the image of the scrollview in viewImage.
Related
At first I use a wkwebView to laod a web url. This url has a video playing.
So I want to have a screenshot like this:
I had used follow API,but it does not work.
UIGraphicsBeginImageContextWithOptions(webView.scrollView.contentSize, true, [UIScreen mainScreen].scale);
{
CGPoint savedContentOffset = webView.scrollView.contentOffset;
CGRect savedFrame = webView.scrollView.frame;
webView.scrollView.contentOffset = CGPointZero;
webView.scrollView.frame = CGRectMake(0, 0, webView.scrollView.contentSize.width, webView.scrollView.contentSize.height);
for (UIView * subView in webView.subviews) {
[subView drawViewHierarchyInRect:subView.bounds afterScreenUpdates:YES];
}
image = UIGraphicsGetImageFromCurrentImageContext();
webView.scrollView.contentOffset = savedContentOffset;
webView.scrollView.frame = savedFrame;
}
UIGraphicsEndImageContext();
I got this photo enter image description here
You can add WebView into the UIView as childview then you can use UIView screenshot to save the webview picture.Like
UIView *tempView = [[UIView alloc] init];
[tempView addChildView:'Your webview'];
[tempView takeSnapshot];
- (UIImage *)takeSnapshot:(UIView *)tempView {
UIGraphicsBeginImageContextWithOptions(self.tempView.bounds.size, NO, [UIScreen mainScreen].scale);
[self drawViewHierarchyInRect:self.tempView.bounds afterScreenUpdates:YES];
// old style [self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
I am trying to take a screen shot of view inside a cell of UITableView but with attached code I can able only to take a screenshot of cell bounds. The problem is that by UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f). I can only make screenshot of rect size and cannot control origin of rect and
rect = [cell bounds]. so please suggest me some idea.
{
UITableViewCell* cell = [self.tableView cellForRowAtIndexPath:path];
__block CGRect rect = [cell bounds];
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
[cell.layer renderInContext:context];
UIImage *capturedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
Take the screenShot as a normal screenShot and then crop it
-(UIImage *)cropImage:(UIImage *)image rect:(CGRect)cropRect
{
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], cropRect);
UIImage *img = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return img;
}
Use like this:
UIImage *img = [self cropImage:viewImage rect:CGRectMake(150,150,100,100)];
To get the frame of a particular tableView Cell. Use this:
CGRect myRect = [tableView rectForRowAtIndexPath:0];//example 0,1,indexPath
Hope this helps. Refer to this link link2
- (UIImage *) screenshot {
CGSize size = CGSizeMake(self.view.frame.size.width, self.view.frame.size.height);
UIGraphicsBeginImageContextWithOptions(size, NO, [UIScreen mainScreen].scale);
CGRect rec = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height); //set the frame
[self.view drawViewHierarchyInRect:rec afterScreenUpdates:YES];
image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
- (UIImage *)createThumbnailImage:(UIImage *)image withSize:(CGSize)size {
CGRect imageRect = CGRectMake(0.0, 0.0, size.width, size.height);
UIGraphicsBeginImageContext(size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextClearRect(context, CGRectMake(0, 0, size.width, size.height));
CGContextSetInterpolationQuality(context, 0.8);
[image drawInRect:imageRect blendMode:kCGBlendModeNormal alpha:1];
UIImage *thumbnail = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return thumbnail;
}
- (void)viewDidLoad {
[super viewDidLoad];
UIImage *inputImage = [UIImage imageNamed:#"dog.jpg"];
UIImage *image = [self createThumbnailImage:inputImage withSize:CGSizeMake(640.0, 480.0)]
}
I got a thumbnail image(640 * 480) by code above. And some odd problem confused me.
When I sent a jpg (10000 * 10000) to the method，it worked well.
But when I sent a png with the same size, the app would crash.
I tried to find some documents about the difference between jpg and png, but it made no sense.
Does anyone have any idea about this bug?
-(UIImage *)getNeedImageFrom:(UIImage*)image cropRect:(CGRect)rect
{
CGImageRef subImage = CGImageCreateWithImageInRect(image.CGImage, rect);
UIImage *croppedImage = [UIImage imageWithCGImage:subImage];
CGImageRelease(subImage);
return croppedImage;
}
can you please check if this solve your problem
This is my code..
extern CGImageRef UIGetScreenImage();
CGRect frame = CGRectMake(0, 0, 320, 548);
CGImageRef cgoriginal = UIGetScreenImage();
CGImageRef cgimg = CGImageCreateWithImageInRect(cgoriginal, frame);
UIImage *viewImage = [UIImage imageWithCGImage:cgimg];
CGImageRelease(cgoriginal);
CGImageRelease(cgimg);
It takes screen shot but not full screen. I know this problem in CGRect frame. But I don't know, how to fix that..
Pay attention that UIGetScreenImage is a private API, so it will be rejected. If you want to do something similar you can try to use -renderInContext on the window layer or -drawViewHierchyInRect(only ios7).
This method should be used as a category on UIView:
- (UIImage *) imageByRenderingViewOpaque:(BOOL) yesOrNO {
UIGraphicsBeginImageContextWithOptions(self.bounds.size, yesOrNO, 0);
if ([self respondsToSelector:#selector(drawViewHierarchyInRect:afterScreenUpdates:)]) {
[self drawViewHierarchyInRect:self.bounds afterScreenUpdates:YES];
}
else {
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
}
UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return resultingImage;
}
You have also this method that you can call on UIScree instance - (UIView *)snapshotViewAfterScreenUpdates:(BOOL)afterUpdates, but that will return only a view not an image.
I encountered a problem when I pinch, pan or rotate a UIImageview in drawInRect, the transform is not being preserved.
How can I preserve the transform in drawInRect?
I tried this but no go :(
- (UIImage*) combineImage:(UIImageView *)selectedImage withOverlay:(UIImageView *)overlayImage
{
/* Identify the region that needs to be cropped */
CGRect viewForImgFrame = self.viewForImg.frame;
NSLog(#"view %#", NSStringFromCGRect(viewForImgFrame));
NSLog(#"selectedImage Img value %#",selectedImage);
NSLog(#"overlayImage Img value %#",overlayImage);
CGSize newImageSize =self.viewForImg.frame.size;
NSLog(#"CGSize %#",NSStringFromCGSize(newImageSize));
UIGraphicsBeginImageContextWithOptions(newImageSize, NO, 0.0); //retina res
//[self.viewForImg.layer renderInContext:UIGraphicsGetCurrentContext()];
[selectedImage.image drawInRect:CGRectMake(0, 0, selectedImage.frame.size.width, selectedImage.frame.size.height)];
CGContextConcatCTM(UIGraphicsGetCurrentContext(), overlayImage.transform);
[overlayImage.image drawInRect:CGRectMake(overlayImage.frame.origin.x, overlayImage.frame.origin.y, overlayImage.frame.size.width, overlayImage.frame.size.height)];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
NSData *imgData = UIImageJPEGRepresentation(image, 0.9); //UIImagePNGRepresentation ( image ); // get JPEG representation
UIImage * imagePNG = [UIImage imageWithData:imgData]; // wrap UIImage around PNG representation
UIGraphicsEndImageContext();
return imagePNG;
}
Any comments are greatly appreciated.
you need to try
CGRectApplyAffineTransform(<#CGRect rect#>, <#CGAffineTransform t#>)
your code should be like
CGContextConcatCTM(UIGraphicsGetCurrentContext(), overlayImage.transform);
CGRect rect = CGRectMake(overlayImage.frame.origin.x, overlayImage.frame.origin.y, overlayImage.frame.size.width, overlayImage.frame.size.height);
CGRect transformedRect = CGRectApplyAffineTransform(rect, overlayImage.transform);
[overlayImage.image drawInRect:transformedRect];
It turned out that the AutoresizingMask changed rect size
[slider setAutoresizingMask:UIViewAutoresizingNone];