dispatch_queue_t DISPATCH_QUEUE_SERIAL在 react native ios 项目中 objective-C 不起作用

问：

我想调用类的委托方法。实现如下，AVCaptureMetadataOutput

//Protocol inheritance
  @interface QRScannerVC : UIViewController<AVCaptureMetadataOutputObjectsDelegate>{

//Code of delegate assignment of AVCaptureMetadataOutput
capturedMetadataOutput = [[AVCaptureMetadataOutput alloc] init];
[_captureSession addOutput:capturedMetadataOutput];
capturedMetadataOutput.metadataObjectTypes = @[AVMetadataObjectTypeQRCode];
dispatch_queue_t dispatchQueue = dispatch_queue_create("qrQueue", DISPATCH_QUEUE_SERIAL);
//Delegate method assignment
[capturedMetadataOutput setMetadataObjectsDelegate:self queue:dispatchQueue];

Delegate method,
- (void)captureOutput:(AVCaptureOutput *)output didOutputMetadataObjects:(NSArray<__kindof AVMetadataObject *> *)metadataObjects fromConnection:(AVCaptureConnection *)connection {

    if (metadataObjects != nil && metadataObjects.count > 0) {
        
        AVMetadataMachineReadableCodeObject *metadataObject = [metadataObjects objectAtIndex:0];
        
        if ([[metadataObject type] isEqualToString:AVMetadataObjectTypeQRCode]) {
            
            [_labelStatus performSelectorOnMainThread:@selector(setText:) withObject:[metadataObject stringValue] waitUntilDone:NO];
            
            [self performSelectorOnMainThread:@selector(stopReading) withObject:nil waitUntilDone:NO];
            _isReading = NO;
        }
    }

根据 apple 文档方法，必须在串行队列上调用才能进行连续流式处理。根据 react native 文档，如果操作需要很长时间才能完成，我们可以调用我们的方法。capturedMetadataOutput:setMetadataObjectsDelegate:queue

但就我而言，方法不调用。如果我在纯 iOS 原生 Objective-C 项目中使用相同的代码，那么它会很好用。 不明白什么是React native中的问题。capturedMetadataOutput:setMetadataObjectsDelegate:queue