if you want to capture the screen is ios app , you can use the following codes:
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
currentCaptureImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
but I want to capture the picture from a specific point, e.g. (start.x, start.y) and with a specific width and height, how can I do this ??
i just google it and got best answer From How to capture a specific size of the self.view
UIGraphicsBeginImageContextWithOptions(CGSizeMake(300, 320), YES, 0.);
[self.view.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
If your view was, for example, 600x320 and you wanted to capture the middle 300 points in width, you'd translate the context 150 points to the left:
UIGraphicsBeginImageContextWithOptions(CGSizeMake(300, 320), YES, 0.);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(context, -150.f, 0.f);
[self.view.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Related
I am using this code to capture the part of iPad screen.
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGRect rect = CGRectMake(500, 500, 600, 600);
CGImageRef imageRef = CGImageCreateWithImageInRect([viewImage CGImage],
rect);
UIImage *img = [UIImage imageWithCGImage:imageRef];
UIImageWriteToSavedPhotosAlbum(img, nil, nil, nil);
CGImageRelease(imageRef);
But this is very slow in comparison to capture part of screen starting from {0,0} to {100,100} using the code
CGRect rect = CGRectMake(0, 0, 200, 200);
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0.0);
CGContextRef context = UIGraphicsGetCurrentContext();
[yourView.layer renderInContext:context];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
The difference between them is the rect size passes to UIGraphicsBeginImageContext. Can we capture CGRectMake(500, 500, 600, 600) without passing complete screen bounds to GraphicContext?
Please write code too.
Sure, you can capture just a smaller part of the view. Create the context at size 600x600, then translate the origin of the context to 500,500 before asking the layer to render.
CGRect rect = CGRectMake(500, 500, 600, 600);
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0.0);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(context, rect.origin.x, rect.origin.y);
[yourView.layer renderInContext:context];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
You might also want to look at the -[UIView drawViewHierarchyInRect:afterScreenUpdates:] method. According to WWDC 2013 Session 226, “Implementing Engaging UI on iOS”, drawViewHierarchyInRect:afterScreenUpdates: is significantly faster than renderInContext:. See slide 41 for a speed comparison: 844 ms for the older method, and 145 ms for the newer method in their example.
This code works:
UIGraphicsBeginImageContextWithOptions(aRect.size, NO, 0.0);
[self.view drawViewHierarchyInRect:aRect afterScreenUpdates:YES];
anImageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
but I need to support iOS 5 and 6. My Googling says this code ought to work:
UIGraphicsBeginImageContextWithOptions(aRect.size, NO, 0.0);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
anImageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
but the image is blank. How do I take a snapshot of a view in iOS 5 and 6?
The solution was to scale the view to fit it the bounds of the graphics context. Most examples I found of this assume that the source view and the destination context are the same size. The graphics context I was using was much smaller than the view being snapshotted, and it was actually just clipping a corner of the view that was transparent.
UIGraphicsBeginImageContextWithOptions(aRect.size, NO, 0.0);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGFloat scale = CGRectGetWidth(aRect) / CGRectGetWidth(self.view.bounds);
CGContextScaleCTM(ctx, scale, scale);
[self.view.layer renderInContext:ctx];
anImageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
I am trying to generate screenshot of UIView which having subview with CATransform3DMakeRotation. Screenshot is generated but it doesn't contain Rotation.
Is it possible to achieve this?
Actual View:
ScreenShot Image
Using following call to Flip the view horizontally...
currentView.layer.transform = CATransform3DConcat(currentView.layer.transform,CATransform3DMakeRotation(M_PI, 0.0, 1.0, 0.0f));
Code for taking screen shot
+ (UIImage *) imageWithView:(UIView *)view
{
CGSize screenDimensions = view.bounds.size;
// Create a graphics context with the target size
// (last parameter takes scale into account)
UIGraphicsBeginImageContextWithOptions(screenDimensions, NO, 0);
// Render the view to a new context
CGContextRef context = UIGraphicsGetCurrentContext();
[view.layer renderInContext:context];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
The "renderInContext" only works for Affine transform. So convert the 3D transform into affine transform like this
currentView.layer.affineTransform = CATransform3DGetAffineTransform(CATransform3DConcat(currentView.layer.transform,CATransform3DMakeRotation(M_PI, 0.0, 1.0, 0.0f)));
Try this code
CGSize newSize = CGSizeMake(yourview.frame.size.width , yourview.frame.size.height);
UIGraphicsBeginImageContextWithOptions(newSize,YES,2.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetInterpolationQuality(context, kCGInterpolationHigh);
[yourview.layer renderInContext:context];
[yourview drawRect:yourview.frame];
UIImage *screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
This might work, try it:
CGRect grabRect = CGRectMake(40,40,300,200);
//for retina displays
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)]) {
UIGraphicsBeginImageContextWithOptions(grabRect.size, NO, [UIScreen mainScreen].scale);
} else {
UIGraphicsBeginImageContext(grabRect.size);
}
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, -grabRect.origin.x, -grabRect.origin.y);
[self.view.layer renderInContext:ctx];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
i have achieved this in one of my application by doing a little tweak like first i capture the whole screen's screen shot and then crop it with the desired frame i need here is a sample code from my app.
- (UIImage *) croppedPhoto
{
[imgcropRectangle setHidden:TRUE];
UIGraphicsBeginImageContext(self.view.frame.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// Create bitmap image from original image data,
// using rectangle to specify desired crop area
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], self.imgcropRectangle.frame);
UIImage *result = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
[imgcropRectangle setHidden:FALSE];
return result;
}
here imgcropRectangle is the UIImageView's object that defines my desired rectangle so i use it's frame for cropping from full screen to desired output. Hope it will help you :)
Try rendering view.layer.presentationLayer instead of view.layer
use this and before passing the view check its subviews :
+ (UIImage *) imageWithView:(UIView *)view
{
UIGraphicsBeginImageContext(CGSizeMake(view.frame.size.width, view.frame.size.height));
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return viewImage
}
I'm trying to get a UIView screen capture on iOS.
In my view I have two UIImageView with animations.
The code that I using it to capture the view is:
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, 1.0);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
// Read the UIImage object
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(image, self,
#selector(image:didFinishSavingWithError:contextInfo:), nil);
The result is an image with the background and only one UIImageView. Both ImageViews are in moviming all the time. If I take several pictures, then the UIImageView is in the same position each time.
Try this one:
-(CGImageRef)imageCapture
{
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGRect rect= CGRectMake(0,0 ,width, height);
CGImageRef imageRef = CGImageCreateWithImageInRect([viewImage CGImage], rect);
return imageRef;
}
use the below line whenever you want to capture the screen
UIImage *captureImg=[[UIImage alloc] initWithCGImage:[self imageCapture]];
How do I take a snapshot / screenshot of the UIWebView control?
The accepted answer is correct, however the screenshot is not in retina resolution.
Using UIGraphicsBeginImageContextWithOptions and set its scale parameter 0.0f makes it capture in native resolution.
UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
CGRect rect = [keyWindow bounds];
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
[keyWindow.layer renderInContext:context];
UIImage *capturedScreen = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Use This:
UIGraphicsBeginImageContext(rect.size);
[webView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
use this code to take a screenshot and save it to the library
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, self, nil, nil);
you can change the screenshot taking portion by changing the
UIGraphicsBeginImageContext(self.view.bounds.size);
to your respective value
try it it will help you