iOS 图片9切

UIImageView *svRect;
    UIImage *backgroundImage = [UIImage imageNamed:@"bg.png"];
    backgroundImage  = [backgroundImage resizableImageWithCapInsets:UIEdgeInsetsMake(15, 15, 15,15)]; //这句就是最关键的了
    svRect = [[UIImageView alloc] initWithImage:backgroundImage];
    [svRect setFrame:CGRectMake(50, 50, 200, 200)];
    [self.view addSubview: svRect];