ios ZXing 扫瞄 条形码问题

在ios 中 扫瞄二维码，条形码基本有 2中第三方的库，一个是zbar 一个是zxing，zxing 在android中表现的比较出色，但是在ios 中不是很好用，扫瞄效率低，我们一般都用zbar，但是有些 条形码就是很奇葩，用zbar无法识别，下面就是一种

 我用了好多ios 的app 都无法识别， 《我查查》，《快拍二维码》，《微信》，自己用zbar都不行，最后用android 手机轻松扫瞄ok，哪我知道为什么了，是zxing可以搞定这种条形码。马上就换了zxing 来测试。 去github 找到了 zxing 的demo。但是悲剧的时无法识别各种条形码。

而且工程还报错。

  报Private field 'cached_y_' not used 编译通不过，解决办法就是

删除工程“buliding setting”的"Other Warning Flags"  的后面的参数：

"-Werror" ，  "-Wno-unused-parameter"  等等

  然后真机debug 完全ok，但是还是无法扫瞄 条形码！为什么呢？

  我在网上着了下原因 ，问题解决了。

方法是：

 

 1.修改 OverlayView.m文件中的61行左右

 

 // self.oneDMode = isOneDModeEnabled;

注释掉。

2.在ZXingWidgetController.m中用这个函数替换以前的函数

 - (void)captureOutput:(AVCaptureOutput *)captureOutput
 didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
        fromConnection:(AVCaptureConnection *)connection
 {
   if (!decoding) {
     return;
   }
   CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
   /*Lock the image buffer*/
   CVPixelBufferLockBaseAddress(imageBuffer,0);
   /*Get information about the image*/
   size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
   size_t width = CVPixelBufferGetWidth(imageBuffer);
   size_t height = CVPixelBufferGetHeight(imageBuffer);

   uint8_t* baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);
   void* free_me = 0;
   if (true) { // iOS bug?
     uint8_t* tmp = baseAddress;
     int bytes = bytesPerRow*height;
     free_me = baseAddress = (uint8_t*)malloc(bytes);
     baseAddress[0] = 0xdb;
     memcpy(baseAddress,tmp,bytes);
   }

   CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
   CGContextRef newContext =
     CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace,
                           kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst);

   CGImageRef capture = CGBitmapContextCreateImage(newContext);
   CVPixelBufferUnlockBaseAddress(imageBuffer,0);
   free(free_me);

   CGContextRelease(newContext);
   CGColorSpaceRelease(colorSpace);

   CGRect cropRect = [overlayView cropRect];
   if (oneDMode) {
     // let's just give the decoder a vertical band right above the red line
 <span style="color:#ff0000;">//    cropRect.origin.x = cropRect.origin.x + (cropRect.size.width / 2) - (ONE_D_BAND_HEIGHT + 1);
 //    cropRect.size.width = ONE_D_BAND_HEIGHT;
 //    // do a rotate
 //    CGImageRef croppedImg = CGImageCreateWithImageInRect(capture, cropRect);
 //    CGImageRelease(capture);
 //    capture = [self CGImageRotated90:croppedImg];
 //    capture = [self CGImageRotated180:capture];
 //    //              UIImageWriteToSavedPhotosAlbum([UIImage imageWithCGImage:capture], nil, nil, nil);
 //    CGImageRelease(croppedImg);
 //    CGImageRetain(capture);
 //    cropRect.origin.x = 0.0;
 //    cropRect.origin.y = 0.0;</span>
     cropRect.size.width = CGImageGetWidth(capture);
     cropRect.size.height = CGImageGetHeight(capture);
   }

   // N.B.
   // - Won't work if the overlay becomes uncentered ...
   // - iOS always takes videos in landscape
   // - images are always 4x3; device is not
   // - iOS uses virtual pixels for non-image stuff

   {
     float height = CGImageGetHeight(capture);
     float width = CGImageGetWidth(capture);

     CGRect screen = UIScreen.mainScreen.bounds;
     float tmp = screen.size.width;
     screen.size.width = screen.size.height;;
     screen.size.height = tmp;

     cropRect.origin.x = (width-cropRect.size.width)/2;
     cropRect.origin.y = (height-cropRect.size.height)/2;
   }
   CGImageRef newImage = CGImageCreateWithImageInRect(capture, cropRect);
   CGImageRelease(capture);
 <span style="color:#ff0000;"> // UIImage *scrn = [[UIImage alloc] initWithCGImage:newImage];
     int backCameraImageOrientation = UIImageOrientationRight;
     UIImage *scrn = [[UIImage alloc] initWithCGImage:newImage scale:
                      (CGFloat)1.0 orientation:backCameraImageOrientation];
 </span>
   CGImageRelease(newImage);
   Decoder *d = [[Decoder alloc] init];
   d.readers = readers;
   d.delegate = self;
   cropRect.origin.x = 0.0;
   cropRect.origin.y = 0.0;
   decoding = [d decodeImage:scrn cropRect:cropRect] == YES ? NO : YES;
   [d release];
   [scrn release];
 }

 也就是上面红色的部分做了修改

3.在ViewController.mm 文件中做下面的修改

 #import "MultiFormatOneDReader.h"

 - (void)pressButton1:(UIButton *)button
 {
   <span style="color:#ff0000;">  ZXingWidgetController *widController = [[ZXingWidgetController alloc] initWithDelegate:self showCancel:YES OneDMode:YES];
     NSMutableSet *readers = [[NSMutableSet alloc] init];
     QRCodeReader *qrcodeReader = [[QRCodeReader alloc] init];

     MultiFormatOneDReader *OneReaders=[[MultiFormatOneDReader alloc]init];

     [readers addObject:qrcodeReader];
      [readers addObject:OneReaders];</span>
     widController.readers = readers;
     [self presentViewController:widController animated:YES completion:^{}];
 }

然后修改全部ok了，扫瞄条形码就完全ok了。

 看效果：

 二：

三：

四：

原文链接：http://blog.csdn.net/justinjing0612/article/details/9337329#comments