图片圆角处理

最近做一个项目，在某一些控件上面要求选中的时候是按钮颜色是绿色，未选中的时候按钮背景图是白色且有灰色的边框，由于选中高亮的时候没有边框，而默认状态有边框，因此我在开发过程中这样处理的，自己生成一张带边框的图片和一张不带边框的图片，具体代码如下：

+ (UIImage *)imageWithBorder:(CGFloat)borderW color:(UIColor *)borderColor image:(UIImage *)image cornerRadius:(CGFloat)radius{
    
    //2.开启一个上下文
    CGSize size = CGSizeMake(image.size.width + 2 * borderW, image.size.height + 2 * borderW);
    UIGraphicsBeginImageContextWithOptions(size, NO, 0);
    //3.绘制大矩形,显示出来
    //UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, size.width, size.height)];
    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, size.width, size.height) cornerRadius:radius];
    [borderColor set];
    [path addClip];
    [path fill];//自动将路径添加到上下文
    //4.绘制一个小矩形,把小圆设置成裁剪区域
    //UIBezierPath *clipPath = [UIBezierPath  bezierPathWithRect:CGRectMake(borderW, borderW, image.size.width, image.size.height)];
    UIBezierPath *clipPath = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(borderW, borderW, image.size.width, image.size.height) cornerRadius:radius];
    [clipPath addClip];//自动将路径添加到上下文，并且超过裁剪区域的路径直接裁减掉，此方法会裁减掉超过大圆的部分
    //5.把图片绘制到上下文当中,drawAtPoint画出的图片大小和image大小相同
    [image drawAtPoint:CGPointMake(borderW, borderW)];
    //6.从上下文当中取出图片
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    //7.关闭上下文
    UIGraphicsEndImageContext();
    
    return newImage;
}

/**
 根据颜色获取一张图片
 @param color 图片的颜色
 @return 图片的实例
 */
+ (UIImage *)imageWithColor:(UIColor *)color size:(CGSize)size {
     //宽高 1.0只要有值就够了
    CGRect rect=CGRectMake(0, 0, size.width, size.height);
    UIGraphicsBeginImageContext(rect.size); //在这个范围内开启一段上下文
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [color CGColor]);//在这段上下文中获取到颜色UIColor
    CGContextFillRect(context, rect);//用这个颜色填充这个上下文
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();//从这段上下文中获取Image属性,,,结束
    UIGraphicsEndImageContext();
    return image;
}

调用

UIImage *greenImage=[UIImage imageWithBorder:0.5 color:[UIColor colorWithHexString:@"23b464"] image:[UIImage imageWithColor:[UIColor colorWithHexString:@"23b464"] size:CGSizeMake(90, 30)] cornerRadius:2.0];
    [self.closeButton setBackgroundImage:greenImage forState:UIControlStateHighlighted];
 UIImage *whiteImae=[UIImage imageWithBorder:0.5 color:[RGB(195, 195, 195)colorWithAlphaComponent:0.7] image:[UIImage imageWithColor:[UIColor whiteColor] size:CGSizeMake(90, 30)] cornerRadius:2.0];

颜色转换的分类
// 颜色转换三：iOS中十六进制的颜色（以#开头）转换为UIColor
+ (UIColor *) colorWithHexString: (NSString *)color{
    NSString *cString = [[color stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
    
    // String should be 6 or 8 characters
    if ([cString length] < 6) {
        return [UIColor clearColor];
    }
    
    // 判断前缀并剪切掉
    if ([cString hasPrefix:@"0X"])
        cString = [cString substringFromIndex:2];
    if ([cString hasPrefix:@"#"])
        cString = [cString substringFromIndex:1];
    if ([cString length] != 6)
        return [UIColor clearColor];
    
    // 从六位数值中找到RGB对应的位数并转换
    NSRange range;
    range.location = 0;
    range.length = 2;
    
    //R、G、B
    NSString *rString = [cString substringWithRange:range];
    
    range.location = 2;
    NSString *gString = [cString substringWithRange:range];
    
    range.location = 4;
    NSString *bString = [cString substringWithRange:range];
    
    // Scan values
    unsigned int r, g, b;
    [[NSScanner scannerWithString:rString] scanHexInt:&r];
    [[NSScanner scannerWithString:gString] scanHexInt:&g];
    [[NSScanner scannerWithString:bString] scanHexInt:&b];
    
    return [UIColor colorWithRed:((float) r / 255.0f) green:((float) g / 255.0f) blue:((float) b / 255.0f) alpha:1.0f];
}

效果图

效果图.png