SurfaceView显示黑屏-Android Studio

问题描述

我希望能够扫描QR码，但是，当应用程序打开时，它仅显示黑屏

我已经尝试了好几天了。非常感谢有人能帮上忙。 可能很小，但我似乎找不到解决方法

MainActivity类

open

}

Android清单

2020-11-06 19:50:00

主要活动XML

{
    "Meta Data": {
        "1. information": "InTraday (5min) open,high,low,close prices and volume","2. Symbol": "IBM","3. Last Refreshed": "2020-11-06 20:00:00","4. Interval": "5min","5. Output Size": "Compact","6. Time Zone": "US/Eastern"
    },"Time Series (5min)": {
        "2020-11-06 20:00:00": {
            "1. open": "114.4400","2. high": "114.4400","3. low": "114.4400","4. close": "114.4400","5. volume": "457"
        },"2020-11-06 19:50:00": {
            "1. open": "114.4000","2. high": "114.4000","3. low": "114.3300","4. close": "114.3300","5. volume": "648"
        }
    }
}

有什么我想念的吗？预先感谢

解决方法

希望这对您有帮助：

MainActivity

private static final int REQUEST_CAMERA_PERMISSION = 201;

您应该添加setAutoFocusEnabled（true）功能

cameraSource = new CameraSource.Builder(this,barcodeDetector)
                .setRequestedPreviewSize(1920,1080)
                .setAutoFocusEnabled(true).build();

surfaceCreated函数检查权限

 @Override
            public void surfaceCreated(SurfaceHolder holder) {
                try {
                    if (ActivityCompat.checkSelfPermission(ScannedBarcodeActivity.this,Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) {
                        cameraSource.start(surfaceView.getHolder());
                    } else {
                        ActivityCompat.requestPermissions(ScannedBarcodeActivity.this,new
                                String[]{Manifest.permission.CAMERA},REQUEST_CAMERA_PERMISSION);
                    }

                } catch (IOException e) {
                    e.printStackTrace();
                }


            }

receiveDetections函数

qrCodes.valueAt(0).displayValue;