在One plus 6和Samsung M20中使用Camera Intent时出现问题

问题描述

在使用Camera Intent时遇到一个问题，在OnActivityResult中，我将currentPhotoPath设置为null。在三星M20（版本10）和一加（版本10）中试用。实现了Google doc的代码形式。相同的代码在Google pixel3（版本11），Redmi note 7s（版本9），Vivo（版本8.1）中都能正常工作。

https://developer.android.com/training/camera/photobasics

还添加代码：

public class MainActivity extends AppCompatActivity {

    Button button;
    String currentPhotoPath;
    TextView textView;
    File photoFile = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = findViewById(R.id.button);
        textView = findViewById(R.id.text);

        button.setonClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                    requestPermissions(new String[]{Manifest.permission.CAMERA,Manifest.permission.READ_EXTERNAL_STORAGE,Manifest.permission.WRITE_EXTERNAL_STORAGE},1);
                }
            }
        });
    }

    @Override
    protected void onStart() {
        super.onStart();
        Log.v("currentPhotoPath","currentPhotoPath onStart  " + currentPhotoPath);
    }

    @Override
    protected void onResume() {
        super.onResume();
        Log.v("currentPhotoPath","currentPhotoPath onResume  " + currentPhotoPath);
    }

    @Override
    protected void onRestart() {
        super.onRestart();
        Log.v("currentPhotoPath","currentPhotoPath onRestart  " + currentPhotoPath);
    }

    @Override
    protected void onPause() {
        super.onPause();
        Log.v("currentPhotoPath","currentPhotoPath onPause  " + currentPhotoPath);
    }

    private void dispatchTakePictureIntent() {
        Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
            try {
                photoFile = createImageFile();
            } catch (IOException ex) {
                ex.printstacktrace();
            }
            if (photoFile != null) {
                Uri photoURI = FileProvider.getUriForFile(this,"com.example.camera.fileprovider",photoFile);
                Log.v("currentPhotoPath","currentPhotoPath file photoFile  " + photoFile.getAbsolutePath());
                takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,photoURI);
                startActivityForResult(takePictureIntent,2);
            }
        }
    }

    @Override
    protected void onActivityResult(int requestCode,int resultCode,@Nullable Intent data) {
        super.onActivityResult(requestCode,resultCode,data);
        if (resultCode == RESULT_OK) {
            if (requestCode == 2) {
                Log.v("currentPhotoPath","currentPhotoPath onActivityResult  " + currentPhotoPath);
                if (currentPhotoPath != null) {
                    textView.setText(currentPhotoPath);
                } else {
                    Toast.makeText(this,"Something went wrong,Unable to pick PDF file",Toast.LENGTH_SHORT).show();
                }
            }
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode,@NonNull String[] permissions,@NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode,permissions,grantResults);
        if (requestCode == 1) {
            dispatchTakePictureIntent();
        }
    }


    private File createImageFile() throws IOException {
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        String imageFileName = "JPEG_" + timeStamp + "_";
        File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
        File image = File.createTempFile(
                imageFileName,/* prefix */
                ".jpg",/* suffix */
                storageDir      /* directory */
        );
        Log.v("currentPhotoPath","currentPhotoPath file path  " + image.getAbsolutePath());
        currentPhotoPath = image.getAbsolutePath();
        Log.v("currentPhotoPath","currentPhotoPath file  " + currentPhotoPath);
        return image;
    }

}

解决方法

第1课：当您的活动不是最重要的活动时，Android OS随时可能终止您的活动。

当相机应用程序排名第一时，您的活动显然被杀死。

将变量保存在onSaveInstanceState（）中，然后在其参数不为null时将其加载回onCreate（）中。