iOS-生成二維碼圖片【附中間帶有小圖標二維碼】（QRCode）

生成二維碼圖片也是項目中常用到的，二維碼的掃描Git上有很多好用的，這里主要說下二維碼的生成

1.普通二維碼

 方法

/**

 生成二維碼

 QRStering：字符串

 imageFloat：二維碼圖片大小

 */

+ (UIImage *)createQRCodeWithString:(NSString *)QRStering withImgSize:(CGFloat)imageFloat;

 

 方法實現

/**

 生成二維碼

 QRStering：字符串

 imageFloat：二維碼圖片大小

 */

+ (UIImage *)createQRCodeWithString:(NSString *)QRString withImgSize:(CGFloat)imageFloat{

    CIFilter *filter = [CIFilter filterWithName:@"XiaoGuiGe"];

    [filter setDefaults];

    NSString *getString = QRString;

    NSData *dataString = [getString dataUsingEncoding:NSUTF8StringEncoding];

    [filter setValue:dataString forKey:@"inputMessage"];

    ///獲取濾鏡輸出的圖像

    CIImage *outImage = [filter outputImage];

    UIImage *imageV = [self imageWithImageSize:imageFloat withCIIImage:outImage];

    //返回二維碼圖像

    return imageV;

}

 

2.中間帶有小圖標的二維碼

 方法

/**

 生成二維碼(中間有小圖片)

 QRStering：字符串

 centerImage：二維碼中間的image對象

 */

+ (UIImage *)createImgQRCodeWithString:(NSString *)QRString centerImage:(UIImage *)centerImage;

 

 方法實現

/**

 生成二維碼(中間有小圖片)

 QRStering：所需字符串

 centerImage：二維碼中間的image對象

 */

+ (UIImage *)createImgQRCodeWithString:(NSString *)QRString centerImage:(UIImage *)centerImage{

    // 創建濾鏡對象

    CIFilter *filter = [CIFilter filterWithName:@"XiaoGuiGe"];

    // 恢復濾鏡的默認屬性

    [filter setDefaults];

    // 將字符串轉換成 NSdata

    NSData *dataString = [QRString dataUsingEncoding:NSUTF8StringEncoding];

    // 設置過濾器的輸入值, KVC賦值

    [filter setValue:dataString forKey:@"inputMessage"];

    // 獲得濾鏡輸出的圖像

    CIImage *outImage = [filter outputImage];

    // 圖片小於(27,27),我們需要放大

    outImage = [outImage imageByApplyingTransform:CGAffineTransformMakeScale(20, 20)];

    // 將CIImage類型轉成UIImage類型

    UIImage *startImage = [UIImage imageWithCIImage:outImage];

    // 開啟繪圖, 獲取圖形上下文

    UIGraphicsBeginImageContext(startImage.size);

    

    // 把二維碼圖片畫上去 (這里是以圖形上下文, 左上角為(0,0)點

    [startImage drawInRect:CGRectMake(0, 0, startImage.size.width, startImage.size.height)];

    // 再把小圖片畫上去

    CGFloat icon_imageW = 200;

    CGFloat icon_imageH = icon_imageW;

    CGFloat icon_imageX = (startImage.size.width - icon_imageW) * 0.5;

    CGFloat icon_imageY = (startImage.size.height - icon_imageH) * 0.5;

    [centerImage drawInRect:CGRectMake(icon_imageX, icon_imageY, icon_imageW, icon_imageH)];

    // 獲取當前畫得的這張圖片

    UIImage *qrImage = UIGraphicsGetImageFromCurrentImageContext();

    // 關閉圖形上下文

    UIGraphicsEndImageContext();

    //返回二維碼圖像

    return qrImage;

}

 

附加方法（與上面兩個方法寫在同一個類）

/** 將CIImage轉換成UIImage 並放大(內部轉換使用)*/

+ (UIImage *)imageWithImageSize:(CGFloat)size withCIIImage:(CIImage *)ciiImage{

    CGRect extent = CGRectIntegral(ciiImage.extent);

    CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));

    // 1.創建bitmap;

    size_t width = CGRectGetWidth(extent) * scale;

    size_t height = CGRectGetHeight(extent) * scale;

    CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();

    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);

    CIContext *context = [CIContext contextWithOptions:nil];

    CGImageRef bitmapImage = [context createCGImage:ciiImage fromRect:extent];

    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);

    CGContextScaleCTM(bitmapRef, scale, scale);

    CGContextDrawImage(bitmapRef, extent, bitmapImage);

    // 2.保存bitmap到圖片

    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);

    CGContextRelease(bitmapRef);

    CGImageRelease(bitmapImage);

    return [UIImage imageWithCGImage:scaledImage];

}