在iPhone中掃描很多次後，條形碼readerview會出現兩次？

Question

我已被使用的條形碼的scanning.I iPad應用正在使用ZBarSDK用於掃描barcodes.Like此我提出的掃描view.`

// ADD: present a barcode reader that scans from the camera feed 
     ZBarReaderViewController *reader = [ZBarReaderViewController new]; 
     reader.readerDelegate = self; 

     reader.supportedOrientationsMask = ZBarOrientationMaskAll; 

     reader.sourceType=UIImagePickerControllerSourceTypeCamera; 
     //reader.cameraDevice = UIImagePickerControllerCameraDeviceFront; 

     reader.cameraOverlayView=cameraOverlay; 

     if([UIImagePickerController isCameraDeviceAvailable:       UIImagePickerControllerCameraDeviceFront ]) 
     { 
      reader.cameraDevice = UIImagePickerControllerCameraDeviceFront; 
     } 
     ZBarImageScanner *scanner = reader.scanner; 

     reader.wantsFullScreenLayout = YES; 
     // 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]; 
     reader.showsZBarControls = NO; 
     // present and release the controller 
     [self temporarilyHideStatusBar]; 
     if(fromscan==YES) 
     { 
      [self presentModalViewController:reader animated:NO]; 
     } 
     else 
     { 
      [self presentModalViewController:reader animated:YES]; 
     } 

     [reader.view addSubview:back]; 
     [back addTarget:self action:@selector(backpressed:) forControlEvents:UIControlEventTouchUpInside]; 

     [reader release]; 

隨後

- (void) imagePickerController: (UIImagePickerController*) reader 
didFinishPickingMediaWithInfo: (NSDictionary*) info 
{ 
    // ADD: get the decode results 
    id<NSFastEnumeration> results = 
    [info objectForKey: ZBarReaderControllerResults]; 
    ZBarSymbol *symbol = nil; 
    for(symbol in results) 
     // EXAMPLE: just grab the first barcode 
     break; 

    //commented blues 
    NSLog(@"%@",symbol.data); 

    [self sdsdsd:symbol.data]; 

    [reader dismissModalViewControllerAnimated:YES]; 


} 

sdssd被我的功能是拍攝這些數據。所有的工作都很完美。但是我的問題是掃描一段時間後，按下掃描覆蓋層的按鈕即將到來，但不允許掃描，覆蓋層內有不同的綠色寄宿生。當我們取消正在顯示，就像掃描已經完成。那是在我下一個頁面goi來自掃描。有誰知道爲什麼會發生這種情況？

Answer 1

試試這個

- (IBAction) scanButtonTapped 
{ 
    // ADD: present a barcode reader that scans from the camera feed 
    ZBarReaderViewController *reader = [ZBarReaderViewController new]; 
    reader.readerDelegate = self; 
    reader.supportedOrientationsMask = ZBarOrientationMaskAll; 

    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]; 

    // present and release the controller 
    [self presentModalViewController: reader 
          animated: YES]; 

} 

- (void) imagePickerController: (UIImagePickerController*) reader didFinishPickingMediaWithInfo: (NSDictionary*) info 
{ 
    // ADD: get the decode results 
    id<NSFastEnumeration> results = 
    [info objectForKey: ZBarReaderControllerResults]; 
    ZBarSymbol *symbol = nil; 

    for(symbol in results) 
     // EXAMPLE: just grab the first barcode 
     break; 

    // EXAMPLE: do something useful with the barcode data 
    resultText.text = symbol.data; 

    // EXAMPLE: do something useful with the barcode image 
    resultImage.image = [info objectForKey: UIImagePickerControllerOriginalImage]; 

    // ADD: dismiss the controller (NB dismiss from the *reader*!) 
    [reader dismissModalViewControllerAnimated: YES]; 
}