在一加 6 和三星 M20 中使用相机意图时出现问题答案

【问题标题】：Issue while using Camera intent in One plus 6 and Samsung M20在一加 6 和三星 M20 中使用相机意图时出现问题
【发布时间】：2020-08-31 07:28:51
【问题描述】：

我在使用相机意图时遇到一个问题，在 OnActivityResult 中我将currentPhotoPath 设为空。在三星 M20（第 10 版）和一加（第 10 版）中尝试实现了 Google 文档的代码。相同的代码在 Google pixel3（版本 11）、Redmi note 7s（版本 9）、Vivo.（版本 8.1）中完美运行。

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

也添加代码：

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;
    }

}

【问题讨论】：

您好，问题解决了吗？

标签： android camera android-camera-intent

【解决方案1】：

第一课：当您的活动不是最重要的活动时，Android 操作系统可以随时终止您的活动。

当相机应用程序成为最重要的应用程序时，您的活动显然会被杀死。

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

【讨论】：