尝试从 - （void）captureoutput返回字符串值，然后将其输出到uitableview

Question

我正在进行此iOS练习并尝试获取存储在NSString detectionString中的条形码数据并输出到tableview。我已经声明了@property NSString * detectionString，但在我的tableview方法中它没有出现

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
    {
        CGRect highlightViewRect = CGRectZero;
        AVMetadataMachineReadableCodeObject *barCodeObject;
        NSString *detectionString = nil;
        NSArray *barCodeTypes = @[AVMetadataObjectTypeUPCECode, AVMetadataObjectTypeCode39Code, AVMetadataObjectTypeCode39Mod43Code,
                                  AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode93Code, AVMetadataObjectTypeCode128Code,
                                  AVMetadataObjectTypePDF417Code, AVMetadataObjectTypeQRCode, AVMetadataObjectTypeAztecCode];



        for (AVMetadataObject *metadata in metadataObjects) {
            for (NSString *type in barCodeTypes) {
                if ([metadata.type isEqualToString:type])
                {
                    barCodeObject = (AVMetadataMachineReadableCodeObject *)[_scanPreviewLayer transformedMetadataObjectForMetadataObject:(AVMetadataMachineReadableCodeObject *)metadata];
                    highlightViewRect = barCodeObject.bounds;

**// the string that contains the barcode data -->**                    self.detectionString = [(AVMetadataMachineReadableCodeObject *)metadata stringValue];

                    break;
                }
            }
            // Conditional statement to test if barcode was scanning

                if (detectionString != nil)
                {
                    _ScanLabel.text = detectionString;

                    break;
                }
                else
                    _ScanLabel.text = @"nil";

            }

            _ScanLaserCaptureView.frame = highlightViewRect;


    }


    - (NSString *)detectionString

    {   **//stored string value, I want to appear on my tableview method**
        return _detectionString;
    }

Answer 1

获取检测字符串后重新加载表格，并通过cellForRowAtIndexPath传递检测字符串。