Ios zbar中的取消按钮操作显示空白视图

我正在iOS应用程序中使用选项卡栏。当我点击“扫描”选项卡时，我调用委托方法立即在“扫描”选项卡上启动相机。当我启动相机扫描QR代码和点击取消按钮扫描之前，我得到的空白视图。相机关闭时如何显示视图

- (void) openCameraScanner
{
    ZBarReaderViewController *reader = [[ZBarReaderViewController alloc] init];
    reader.readerDelegate = self;
    reader.supportedOrientationsMask = ZBarOrientationMaskAll;
    reader.showsZBarControls = YES;

    ZBarImageScanner *scanner = reader.scanner;
    [scanner setSymbology: ZBAR_I25
                   config: ZBAR_CFG_ENABLE
                       to: 0];
    [self presentViewController:reader animated:YES completion:nil];
    reader.showsZBarControls = YES;
    //reader.cameraOverlayView = [self commonOverlay];
}

- (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
    //resultsView.text = symbol.data;
    NSString *urlString = symbol.data;
    NSURL *url = [NSURL URLWithString:urlString];
    NSLog(@"Query after scan = %@", [url query]);

    //Extract id from URL which is there in QR Code --- start
    NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
    for(NSString *param in [urlString componentsSeparatedByString:@"&"])
    {
        NSArray *elements = [param componentsSeparatedByString:@"="];
        if([elements count]<2)
            continue;
        [dictionary setObject:[elements objectAtIndex:1] forKey:[elements objectAtIndex:0]];
        NSLog(@"value is == %@", [elements objectAtIndex:1]);
    //Extract id from URL which is there in QR Code --- end

        if([[elements objectAtIndex:1] intValue])
        {
            NSUserDefaults *defaultsForAsk = [NSUserDefaults standardUserDefaults];
            idToAsk = [NSString stringWithFormat:@"%d",[[elements objectAtIndex:1] intValue]];
            [defaultsForAsk setObject:idToAsk forKey:@"IDTOASKVIEW"];


            flagToShowView = YES;
            listViewCntrl.getFlag = flagToShowView;
            [self viewDidLoadForDynamicFields];

        }
        else if([elements objectAtIndex:1] == [NSNull null])
        {
            [reader dismissViewControllerAnimated:YES completion:Nil];
            UIAlertView *message = [[UIAlertView alloc] initWithTitle:@"Invalid QR Code scanned" message:@"Please scan Collaborator's QR Code" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
            [message show];
        }
    }

    image.image =
    [info objectForKey: UIImagePickerControllerOriginalImage];

    // ADD: dismiss the controller (NB dismiss from the *reader*!)
    //[reader dismissViewControllerAnimated:YES completion:nil];

    [reader dismissViewControllerAnimated:YES completion:Nil];

}

-（无效）openCameraScanner
{
ZBarReaderViewController*读卡器=[[ZBarReaderViewController alloc]init]；
reader.readerDelegate=self；
reader.supportedOrientationMask=zBaroOrientationMaskall；
reader.showsZBarControls=是；
ZBarImageScanner*scanner=reader.scanner；
[扫描仪设置符号：ZBAR_I25]
配置：ZBAR_CFG_启用
至：0]；
[自我呈现视图控制器：读卡器动画：是完成：无]；
reader.showsZBarControls=是；
//reader.cameraOverlayView=[self commonOverlay]；
}
-（无效）imagePickerController:（UIImagePickerController*）读卡器
didFinishPickingMediaWithInfo:（NSDictionary*）信息
{
//添加：获取解码结果
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
//resultsView.text=symbol.data；
NSString*urlString=symbol.data；
NSURL*url=[NSURL URLWithString:urlString]；
NSLog（@“扫描后查询=%@，[url查询]）；
//从QR码中的URL提取id---开始
NSMutableDictionary*dictionary=[[NSMutableDictionary alloc]init]；
对于（在[urlString componentsSeparatedByString:@“&”]中的NSString*参数）
{
NSArray*元素=[param componentsSeparatedByString:@“=”]；
如果（[elements count]您可以使用-（void）ViewWillDisplay:（BOOL）ViewController类的动画方法重新显示视图。
从何处显示Zbar扫描视图控制器？从视图控制器或子类tabbar控制器？我添加了[self-openCameraScanner]在viewDidLoad中..我还调用了openCameraScanner in ViewWillDisplay和ViewDidDisplay，但这并没有解决问题。您是否能够在设备中启动摄像头，但在关闭读卡器时遇到问题？正确吗？@Jailanihabeb yes..按取消按钮会显示一个空白视图，而不是nib。这可能是因为dismissModalViewController已清除润滑，dismissViewControllerAnimated正在创建此问题..？。可能是…这可能是因为我更改了IOS7的弃用函数。这并不能解决此问题。在我点击zbar相机的“取消”按钮后，我得到的是一个空白视图，而不是xib nib视图