ios - Zbar sdk 扫描仪无法正常工作

Question

在我的应用程序中，我集成了 Zbar SDK 扫描器，虽然扫描通常可以正常工作，但我的情况有时是 didfinishpickingmediawithInfo: 委托(delegate)方法触发两次。这是我在单音类中的代码。

-(void)scanProductBarCode
{

        ZBarReaderViewController *reader = [ZBarReaderViewController new];
        reader.readerDelegate = self;


        if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
            reader.supportedOrientationsMask = ZBarOrientationMaskLandscape;
        else
            reader.supportedOrientationsMask = ZBarOrientationMaskPortrait;

        ZBarImageScanner *scanner = reader.scanner;
        [scanner setSymbology: ZBAR_UPCA config: ZBAR_CFG_ENABLE to: 1];
        [scanner setSymbology: ZBAR_CODE39 config: ZBAR_CFG_ADD_CHECK to: 0];


}

#pragma mark - Scanner delegate methods

- (void) imagePickerController: (UIImagePickerController*) reader didFinishPickingMediaWithInfo: (NSDictionary*) info
{
    id<NSFastEnumeration> results = [info objectForKey: ZBarReaderControllerResults];
    ZBarSymbol *symbol = nil;
    for(symbol in results)
        break;

    barCodeString = [[NSString alloc] initWithString:symbol.data];

    if(self.delegate)
        [self.delegate getBarcodeString:barCodeString];

    [reader dismissModalViewControllerAnimated:YES];


}

看这个屏幕截图:



在后台，扫描仪在两次发生的情况下仍然像这样运行..

Answer 1

我遇到了同样的问题。我添加了 BOOL我的类的实例变量 _processing .然后我这样做了:

- (void)imagePickerController:(UIImagePickerController*)reader didFinishPickingMediaWithInfo:(NSDictionary*)info
{
    if (_processing) return;

    id<NSFastEnumeration> results = [info objectForKey:ZBarReaderControllerResults];
    ZBarSymbol *symbol = nil;
    for(symbol in results) {
        _processing = YES;
        barCodeString = symbol.data;

        if(self.delegate) {
            [self.delegate getBarcodeString:barCodeString];
        }

        break;
    }

    [reader dismissModalViewControllerAnimated:YES];
}

这确保只处理第一个调用。您可能需要重置 _processing如果您打算多次重用 View Controller 。