iOS
Instantánea de UIView

Obtención de la instantánea

- (UIImage *)getSnapshot 
{      
UIScreen *screen = [UIScreen mainScreen];
CGRect bounds = [self.view bounds];
UIGraphicsBeginImageContextWithOptions(bounds.size, false, screen.scale);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetInterpolationQuality(context, kCGInterpolationHigh);
[self.view drawViewHierarchyInRect:bounds afterScreenUpdates:YES];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();  
return image;
}

Rápido

var screenshot: UIImage
{
UIGraphicsBeginImageContext(self.bounds.size);
let context = UIGraphicsGetCurrentContext();
self.layer.render(in: context)
let screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return screenShot
}

Instantánea con subvista con otro marcado y texto.

• Soporta retrato y paisaje tanto tipo de imagen
• El dibujo y otras subvistas se pueden combinar en mi caso. Estoy agregando una etiqueta al dibujo.

{
    CGSize fullSize = getImageForEdit.size;
    CGSize sizeInView = AVMakeRectWithAspectRatioInsideRect(imgViewFake.image.size, imgViewFake.bounds).size;
    CGFloat orgScale = orgScale = fullSize.width/sizeInView.width;
    CGSize newSize = CGSizeMake(orgScale * img.image.size.width, orgScale * img.image.size.height);
    if(newSize.width <= fullSize.width && newSize.height <= fullSize.height){
        newSize = fullSize;
    }
    CGRect offsetRect;
    if (getImageForEdit.size.height > getImageForEdit.size.width){
        CGFloat scale = newSize.height/fullSize.height;
        CGFloat offset = (newSize.width - fullSize.width*scale)/2;
        offsetRect = CGRectMake(offset, 0, newSize.width-offset*2, newSize.height);
    }
    else{
        CGFloat scale = newSize.width/fullSize.width;
        CGFloat offset = (newSize.height - fullSize.height*scale)/2;
        offsetRect = CGRectMake(0, offset, newSize.width, newSize.height-offset*2);
    }
    UIGraphicsBeginImageContextWithOptions(newSize, NO, getImageForEdit.scale);
    [getImageForEdit drawAtPoint:offsetRect.origin];
    //        [img.image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
    CGFloat oldScale = img.contentScaleFactor;
    img.contentScaleFactor = getImageForEdit.scale;
    [img drawViewHierarchyInRect:CGRectMake(0, 0, newSize.width, newSize.height) afterScreenUpdates:YES];
    img.contentScaleFactor = oldScale;
    UIImage *combImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    imageData = UIImageJPEGRepresentation(combImage, 1);
}