在ios中使用ZBarReaderViewController导致条形码不一致

我正在做一个iOS应用程序，其中我必须扫描条形码。我使用ZBarReaderViewController扫描条形码。有时它给出的结果是准确的，但有时它给出的是未知值，如图所示

 -(IBAction)scanBarCode:(id)sender
{
reader = [ZBarReaderViewController new];
     reader.readerDelegate = self;
     reader.supportedOrientationsMask = ZBarOrientationMaskAll;
    reader.cameraFlashMode = UIImagePickerControllerCameraFlashModeOff;  

if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone && [UIScreen mainScreen].bounds.size.height * [UIScreen mainScreen].scale >= 1136)
    [reader.readerView setScanCrop:(CGRect){ { 0.25, 0.08 }, { 0.07, 0.84} }];//.25
else
    [reader.readerView setScanCrop:(CGRect){ { 0.23, 0.08 }, { 0.09, 0.84} }];

 ZBarImageScanner *scanner = reader.scanner;
 // TODO: (optional) additional reader configuration here

 // EXAMPLE: disable rarely used I2/5 to improve performance
 /*[scanner setSymbology: ZBAR_I25
 config: ZBAR_CFG_ENABLE
 to: 0];*/

//swetha test
[scanner setSymbology: 0
               config: ZBAR_CFG_ENABLE
                   to: 0];
// Enable EAN 13
[scanner setSymbology: ZBAR_EAN13
               config: ZBAR_CFG_ENABLE
                   to: 1];
// Enable UPC-A
[scanner setSymbology: ZBAR_UPCA
               config: ZBAR_CFG_ENABLE
                   to: 1];
// Enable Code 128
[scanner setSymbology: ZBAR_CODE128
               config: ZBAR_CFG_ENABLE
                   to: 1];
 [self presentViewController:reader animated:YES completion:nil];
 [reader release];

}

-（void）imagePickerController:（UIImagePickerController*）选取器未使用信息完成PickingMediaWithInfo:（NSDictionary*）信息
{
id结果=
[信息对象forkey:ZBarReaderControllerResults]；
ZBarSymbol*符号=nil；
用于（结果中的符号）
//示例：只需抓取第一个条形码
打破
//示例：对条形码数据执行一些有用的操作
serialnumber.text=symbol.data；
//示例：对条形码图像执行一些有用的操作
//结果图像=
//[info objectForKey:UIImagePickerControllerOriginalImage]；
//添加：关闭控制器（注意从*读卡器*！）
barcodeClicked=0；
[picker DismissionViewControllerInitiated:是完成：无]；
}

---

如果我不清楚，请告诉我。提前感谢。

我的ImagePickerControl功能如下：

- (void) imagePickerController: (UIImagePickerController*)reader didFinishPickingMediaWithInfo: (NSDictionary*) info {
  @try {
    id<NSFastEnumeration> results = [info objectForKey: ZBarReaderControllerResults];
    for(id obj in results) {
      ZBarSymbol *symbol = obj;
      serialnumber.text = [symbol data];
    }
  }
  @catch (NSException *ex) {
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:[NSString stringWithFormat:@"%@",ex]
                                                delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil];
    [alert show];
  }
  barcodeClicked = 0;
  [reader dismissViewControllerAnimated:YES completion:nil];  
}

-（void）imagePickerController:（UIImagePickerController*）读卡器已使用信息完成PickingMediaWithInfo:（NSDictionary*）信息{
@试一试{
id结果=[info objectForKey:ZBarReaderControllerResults]；
对于（结果中的id obj）{
ZBarSymbol*symbol=obj；
serialnumber.text=[符号数据]；
}
}
@捕获（NSException*ex）{
UIAlertView*alert=[[UIAlertView alloc]initWithTitle:@“错误”消息：[NSString stringWithFormat:@“%@”，ex]
代表：自我取消按钮：@“确定”其他按钮：无]；
[警报显示]；
}
barcodeClicked=0；
[reader DismissViewControllerInitiated:YES completion:nil]；
}

我强烈建议使用try-catch并查看所有结果，因为如果附近有两个不同的条形码，它可能会解释它们，并将对象解析为ZBarSymbol

- (void) imagePickerController: (UIImagePickerController*)reader didFinishPickingMediaWithInfo: (NSDictionary*) info {
  @try {
    id<NSFastEnumeration> results = [info objectForKey: ZBarReaderControllerResults];
    for(id obj in results) {
      ZBarSymbol *symbol = obj;
      serialnumber.text = [symbol data];
    }
  }
  @catch (NSException *ex) {
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:[NSString stringWithFormat:@"%@",ex]
                                                delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil];
    [alert show];
  }
  barcodeClicked = 0;
  [reader dismissViewControllerAnimated:YES completion:nil];  
}