图片

iOS

// 根据 color 得到 image
+ (UIImage *)imageWithColor:(UIColor *)color rect:(CGRect)rect {

    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context,
                                   color.CGColor);
    CGContextFillRect(context, rect);
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return img;
}