Iphone 4和Iphone 5的图像

Question

My app can have many images for background . This images I need download, so I don't want download separately for iPhone 4 and iPhone 5 . I use method self.view.backgroundcolor = [UIColor colorWithPatternImage:[UIImage imagenamed:@"myImage.jpg"]] . I want download one image for iPhone 5 and then cut top and bottom borders for use with iPhone 4 . How can I do it programmatically with the best way. Oh maybe there are the best solutions for my problem?

Answer 1

You can crop image using this function define the rect you want as image remaining will be removed for this you need CoreGraphics.framework , so dont forget to add in your Project.

- (UIImage *)imageByCroppingtoRect:(CGRect)rect fromImage:(UIImage *)image
{
    CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], rect);
    UIImage *cropped = [UIImage imageWithCGImage:imageRef];
    CGImageRelease(imageRef);
    return cropped;
}

Answer 2

try this

- (UIImage *)cropImage:(UIImage *)oldImage {
    CGSize imageSize = oldImage.size;
    UIGraphicsBeginImageContextWithOptions(CGSizeMake( imageSize.width,imageSize.height - 100),NO,0.); // this height you want to change
    [oldImage drawAtPoint:CGPointMake( 0, -46) blendMode:kCGBlendModeCopy alpha:1.];// from top to change X is never change
    UIImage *croppedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return croppedImage;
}