使用颜色当图片

大部分是用来设置UIButton 的backgroundImage

- (UIImage*)buttonImageFromColor:(UIColor*)color{    CGRect rect = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);    UIGraphicsBeginImageContext(rect.size);    CGContextRef context = UIGraphicsGetCurrentContext();    CGContextSetFillColorWithColor(context, [color CGColor]);    CGContextFillRect(context, rect);    UIImage* img = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    return img;}