UIImageView xib里面拉伸图片技巧

拉伸图片的时候代码里和xib里面的图片名字去掉@2x,但是原始图片文件得要[e-mail]

The X and Y values seem to be the positions for the stretch starting point, relative to the entire width and height of the image, i.e. 0.5 would mean a point in the middle of the image.

Same thing for the Width and Height: sizes for the stretchable area, relative to the image size, i.e. setting it to a value of 1 / imageWidth would mean the stretchable area is 1 pixel wide. The strange thing is 0 also work fine for the blue pill button (could be for convenience reasons?).

Below, view modes are set to "Scale to Fill". The images are stretchable images from​​ This answer was inspired by

In cases where you want more than one pixel to stretch (ie. a pattern in the center of the button) the stretchable UIImage does not work.

The UIButton's contentStretch does also not work properly.

How I solved it: I subclassed UIButton and added a ​​UIImageView *backgroundImageView​ ​ as property and placed it at index 0 as a subview within the ​​UIButton​​. I then ensure in layoutSubviews that it fits the button entirely and set the highlighted states of the imageView. All you need to do is handover a UIImageView with the correct contentStretch and contentMode applied.

.h file

@interface ButtonWithBackgroundImage : UIButton {
    UIImageView *backgroundImageView;
}
@property (retain) UIImageView *backgroundImageView;
+ (ButtonWithBackgroundImage*)button;
@end

.m file

@implementation ButtonWithBackgroundImage
@synthesize backgroundImageView;

+ (ButtonWithBackgroundImage*)button {
return [self buttonWithType:UIButtonTypeCustom];
}
- (void)setBackgroundImageView:(UIImageView*)img {
    [backgroundImageView removeFromSuperview];
    [backgroundImageView release];

    backgroundImageView = [img retain];

    if(backgroundImageView){
        [self insertSubview:backgroundImageView atIndex:0];
        [self setNeedsLayout];
    }
}

- (void)setSelected:(BOOL)select {
    [super setSelected:select];
    // we subclass the setSelect method to highlight the background imageview
[backgroundImageView setHighlighted:select||self.highlighted];
}
- (void)setHighlighted:(BOOL)highl {
    [super setHighlighted:highl];

    // we subclass the setHighlighted method to highlight the background imageview    
    [backgroundImageView setHighlighted:highl||self.selected];
}

- (void)layoutSubviews {
    [super layoutSubviews];

    self.backgroundImageView.frame = self.bounds;
}

- (void)dealloc {
    [backgroundImageView release];
    backgroundImageView = nil;
    [super dealloc];
}
@end