最近做一個項目，在某一些控件上面要求選中的時候是按鈕顏色是綠色，未選中的時候按鈕背景圖是白色且有灰色的邊框，由于選中高亮的時候沒有邊框，而默認狀態有邊框，因此我在開發過程中這樣處理的，自己生成一張帶邊框的圖片和一張不帶邊框的圖片，具體代碼如下：

+ (UIImage *)imageWithBorder:(CGFloat)borderW color:(UIColor *)borderColor image:(UIImage *)image cornerRadius:(CGFloat)radius{
    
    //2.開啟一個上下文
    CGSize size = CGSizeMake(image.size.width + 2 * borderW, image.size.height + 2 * borderW);
    UIGraphicsBeginImageContextWithOptions(size, NO, 0);
    //3.繪制大矩形,顯示出來
    //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];//自動將路徑添加到上下文
    //4.繪制一個小矩形,把小圓設置成裁剪區域
    //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];//自動將路徑添加到上下文，并且超過裁剪區域的路徑直接裁減掉，此方法會裁減掉超過大圓的部分
    //5.把圖片繪制到上下文當中,drawAtPoint畫出的圖片大小和image大小相同
    [image drawAtPoint:CGPointMake(borderW, borderW)];
    //6.從上下文當中取出圖片
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    //7.關閉上下文
    UIGraphicsEndImageContext();
    
    return newImage;
}

/**
 根據顏色獲取一張圖片
 @param color 圖片的顏色
 @return 圖片的實例
 */
+ (UIImage *)imageWithColor:(UIColor *)color size:(CGSize)size {
     //寬高 1.0只要有值就夠了
    CGRect rect=CGRectMake(0, 0, size.width, size.height);
    UIGraphicsBeginImageContext(rect.size); //在這個范圍內開啟一段上下文
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [color CGColor]);//在這段上下文中獲取到顏色UIColor
    CGContextFillRect(context, rect);//用這個顏色填充這個上下文
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();//從這段上下文中獲取Image屬性,,,結束
    UIGraphicsEndImageContext();
    return image;
}

調用

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];

顏色轉換的分類
// 顏色轉換三：iOS中十六進制的顏色（以#開頭）轉換為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];
    }
    
    // 判斷前綴并剪切掉
    if ([cString hasPrefix:@"0X"])
        cString = [cString substringFromIndex:2];
    if ([cString hasPrefix:@"#"])
        cString = [cString substringFromIndex:1];
    if ([cString length] != 6)
        return [UIColor clearColor];
    
    // 從六位數值中找到RGB對應的位數并轉換
    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];
}

效果圖

效果圖.png