UIButton 設置背景圖片 拉伸效果

    必須是自定義的按鈕類型

    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];

    UIImage *normal = [UIImage resizableImage:@"RedButton"];

    UIImage *high = [UIImage resizableImage:@"RedButtonPressed"];

    

    [button setBackgroundImage:normal forState:UIControlStateNormal];

    [button setBackgroundImage:high forState:UIControlStateHighlighted];

#import <UIKit/UIKit.h>

@interface UIImage (Extension)

+ (UIImage *)resizableImage:(NSString *)name;

@end

#import "UIImage+Extension.h"

@implementation UIImage (Extension)

/**

 *  返回一張能夠隨意拉伸不變形的圖片

 *

 *  @param name 圖片名字

 */

+ (UIImage *)resizableImage:(NSString *)name

{

    UIImage *normal = [UIImage imageNamed:name];

    CGFloat w = normal.size.width * 0.5;

    CGFloat h = normal.size.height * 0.5;

    return [normal resizableImageWithCapInsets:UIEdgeInsetsMake(h, w, h, w)];

}

@end