Android相机黑色屏幕

Question

我想创建一个应用程序，将读取QR码，此代码间歇性地工作，但它会给权限错误，并不会加载。我相信我有这些修复，但现在我得到一个黑屏。没有错误，所以我不知道在哪里看，但我觉得它与权限有关。

package com.sample.qrcodereadervision.Activity; 

import com.google.android.gms.vision.CameraSource; 
import com.google.android.gms.vision.Detector; 
import com.google.android.gms.vision.barcode.Barcode; 
import com.google.android.gms.vision.barcode.BarcodeDetector; 

import com.sample.qrcodereadervision.R; 

import android.Manifest; 
import android.content.pm.PackageManager; 
import android.os.Bundle; 
import android.support.annotation.NonNull; 
import android.support.design.widget.Snackbar; 
import android.support.v4.app.ActivityCompat; 
import android.support.v4.content.ContextCompat; 
import android.support.v7.app.AppCompatActivity; 
import android.util.Log; 
import android.util.SparseArray; 
import android.view.SurfaceView; 
import android.view.View; 
import android.widget.TextView; 
import android.widget.Toast; 

import java.io.IOException; 

import permissions.dispatcher.NeedsPermission; 
import permissions.dispatcher.OnPermissionDenied; 
import permissions.dispatcher.OnShowRationale; 
import permissions.dispatcher.PermissionRequest; 
import permissions.dispatcher.PermissionUtils; 
import permissions.dispatcher.RuntimePermissions; 

@RuntimePermissions 
public class QRcodeReader extends AppCompatActivity { 
    public final String TAG = getClass().getSimpleName(); 

    private CameraSource cameraSource; 
    /** UI Parts : Preview screen */ 
    private SurfaceView cameraView; 
    /** UI Parts : decoding results */ 
    private TextView barcodeInfo; 

    private static final int REQUEST_CAMERA = 0x00000011; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     Log.d("QRcodeReader", "onCreate"); 
     setContentView(R.layout.activity_main); 

     if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) 
       != PackageManager.PERMISSION_GRANTED) { 
      requestCameraPermission(); 
     } 

    } 

    @Override 
    protected void onStart() { 
     super.onStart(); 
     Log.d(TAG, "onStart"); 
     barcodeInfo = (TextView) findViewById(R.id.code_info); 
     cameraView = (SurfaceView) findViewById(R.id.camera_view); 
     startQRcodeReader(); 
//  startCameraSource(); 
    } 

    @Override 
    protected void onPause() { 
     super.onPause(); 
     Log.d(TAG, "onPause"); 
    } 

    //@Override 
    //public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { 
    // Log.d(TAG, "onRequestPermissionsResult"); 
    // QRcodeReaderPermissionsDispatcher.onRequestPermissionsResult(this, requestCode, grantResults); 
    //} 

    private void startQRcodeReader() { 
     Log.d(TAG, "startQRcodeReader"); 
     BarcodeDetector barcodeDetector = new BarcodeDetector.Builder(this) 
       .setBarcodeFormats(Barcode.QR_CODE) 
       .build(); 

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

     QRcodeReaderPermissionsDispatcher.startCameraSourceWithCheck(QRcodeReader.this); 
     //requestCameraPermission(); 

     //QR Code reading 
     barcodeDetector.setProcessor(
       new Detector.Processor<Barcode>() { 
        @Override 
        public void release() { 
        } 

        @Override 
        public void receiveDetections(Detector.Detections<Barcode> detections) { 
         final SparseArray<Barcode> barcodes = detections.getDetectedItems(); 
         if (barcodes.size() != 0) { 
          barcodeInfo.post(
            new Runnable() { 
             public void run() { 
              barcodeInfo.setText(
                barcodes.valueAt(0).displayValue 
              ); 
             } 
            }); 
         } 
        } 
       }); 
    } 

    @NeedsPermission(Manifest.permission.CAMERA) 
    void startCameraSource() { 
     Log.d(TAG, "startCameraSource"); 
     Toast.makeText(this, "\n" + 
       "Start the camera source", Toast.LENGTH_SHORT) 
       .show(); 
     try { 
      releaseCameraAndPreview(); 
      if (cameraSource != null) { 
       if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) { 
        cameraSource.start(cameraView.getHolder()); 
        return; 
       } 

      } 
     } catch (IOException | SecurityException e) { 
      Log.w(TAG, e); 
     } 
    } 


    @SuppressWarnings("unused") 
    @OnPermissionDenied(Manifest.permission.CAMERA) 
    void deniedPermission() { 
     Log.d(TAG, "deniedPermission"); 
     if (PermissionUtils.shouldShowRequestPermissionRationale(this, Manifest.permission.CAMERA)) { 
      Toast.makeText(this, "\n" + 
        "It failed to camera startup .", Toast.LENGTH_SHORT) 
        .show(); 
     } 
    } 

    @SuppressWarnings("unused") 
    @OnShowRationale(Manifest.permission.CALL_PHONE) 
    void showRationalForStorage(final PermissionRequest request) { 
     Log.d(TAG, "showRationalForStorage"); 
     Toast.makeText(this, "\n" + 
       "The camera of the use permit is required", Toast.LENGTH_SHORT) 
       .show(); 
     request.proceed(); 
    } 

    private void releaseCameraAndPreview() { 
     if (cameraSource != null) { 
      cameraSource.release(); 
      cameraSource = null; 
     } 
    } 

    private void requestCameraPermission() { 
     Log.i(TAG, "CAMERA permission has NOT been granted. Requesting permission."); 

     if (ActivityCompat.shouldShowRequestPermissionRationale(this, 
       Manifest.permission.CAMERA)) { 
      Log.i(TAG, 
        "Displaying camera permission rationale to provide additional context."); 
      Snackbar.make(findViewById(R.id.code_info), R.string.permission_camera_rationale, 
        Snackbar.LENGTH_INDEFINITE) 
        .setAction(R.string.ok, new View.OnClickListener() { 
         @Override 
         public void onClick(View view) { 
          ActivityCompat.requestPermissions(QRcodeReader.this, 
            new String[]{Manifest.permission.CAMERA}, 
            REQUEST_CAMERA); 
         } 
        }) 
        .show(); 
     } else { 

      ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA}, 
        REQUEST_CAMERA); 
     } 
    } 

    @Override 
    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], 
     @NonNull int[] grantResults) { 
     Log.d(TAG, "onRequestPermissionsResult"); 
     switch (requestCode) { 
      case REQUEST_CAMERA: { 
       // If request is cancelled, the result arrays are empty. 
       if (grantResults.length > 0 
         && grantResults[0] == PackageManager.PERMISSION_GRANTED) { 

        QRcodeReaderPermissionsDispatcher.onRequestPermissionsResult(this, requestCode, grantResults); 
        startCameraSource(); 

       } else { 

        finish(); 
       } 
      } 
      break; 
     } 
    } 

} 

舱单

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="com.sample.qrcodereadervision"> 

    <uses-permission android:name="android.permission.CAMERA" /> 
    <uses-feature android:name="android.hardware.camera" /> 
    <uses-feature android:name="android.hardware.camera.autofocus"/> 

    <application 
     android:theme="@style/AppTheme" 
     android:label="@string/app_name" 
     android:allowBackup="true" 
     android:icon="@mipmap/ic_launcher" 
     android:supportsRtl="true"> 

     <activity android:name=".Activity.QRcodeReader"> 
      <intent-filter> 
       <action android:name="android.intent.action.MAIN"/> 

       <category android:name="android.intent.category.LAUNCHER"/> 
      </intent-filter> 
     </activity> 

     <meta-data android:name="com.google.android.gms.vision.DEPENDENCIES" android:value="barcode"/> 
    </application> 

</manifest> 

Answer 1

添加相同权限的清单中也是如此。