Question

我的应用程序是用于从用户获取文本（String）并将其保存在内部和/或外部存储中，从中读取，问题是从我尝试在虚拟设备上运行应用程序的大约两个日期开始操作系统android 7.0.1“Nougat”和应用程序跳过/忽略写入外部存储权限即使我看到当我点击外部缓存按钮时出现权限对话框方

我的问题是：这是不是需要为Android OS android marshmallow及以上版本创建权限方法？

见此GIF相关

整个代码

    public class MainFragment extends android.app.Fragment {

    private View view;
    private EditText userName2;
    private Button internalButton, externalButton, showData;
    FileOutputStream fileOutputStream;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        view = inflater.inflate(R.layout.fragment_main, container, false);
        userName2 = view.findViewById(R.id.editTextUserName);
        internalButton = view.findViewById(R.id.internalButton);
        externalButton = view.findViewById(R.id.externalButton);
        showData = view.findViewById(R.id.showData);

        internalButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                saveToInternalCache();
            }
        });

        externalButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                enableRunTimePermisstion();


            }
        });

        showData.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(getActivity(), DataActivity.class);
                startActivity(intent);
            }
        });

        return view;

    }


    @TargetApi(23)
    public void enableRunTimePermisstion() {
        if ((Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) &&
                (getContext().checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) !=
                        PackageManager.PERMISSION_GRANTED))
            if (getActivity().shouldShowRequestPermissionRationale
                (Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            Toast.makeText(getActivity(), "Write storage permission is need for app"
                    , Toast.LENGTH_LONG).show();
        } else {
            requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
            Toast.makeText(getActivity(), "request permission"
                    , Toast.LENGTH_LONG).show();
        }
        saveToExternalCache();

    }


    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == 1) {
            if (permissions[0].equals(Manifest.permission.WRITE_EXTERNAL_STORAGE) &&
                    grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                Toast.makeText(getActivity(), "Write external storage granted", Toast.LENGTH_LONG).show();
                saveToExternalCache();
            }
        } else {
            Toast.makeText(getActivity(), "Write external permission denied", Toast.LENGTH_SHORT).show();
            enableRunTimePermisstion();
        }
    }


    public void saveToInternalCache() {
        String userName = userName2.getText().toString();
        File path = getActivity().getCacheDir();
        File file = new File(path, "dataInternal.txt");
        try {
            fileOutputStream = new FileOutputStream(file);
            fileOutputStream.write(userName.getBytes());
            Toast.makeText(getActivity(), "Data stored successfully" + file.getAbsolutePath(), Toast.LENGTH_LONG).show();
        } catch (IOException e) {
            Log.e("IOException", e.toString());
        } finally {
            try {
                fileOutputStream.close();
            } catch (IOException e) {
                Log.e("IOException", e.toString());
            }
        }


    }

    public void saveToExternalCache() {
        String userName = userName2.getText().toString();
        File path = getActivity().getExternalCacheDir();
        File file = new File(path, "dataExternal.txt");
        try {
            fileOutputStream = new FileOutputStream(file);
            fileOutputStream.write(userName.getBytes());
            Toast.makeText(getActivity(), "Data stored successfully"
                    + file.getAbsolutePath(), Toast.LENGTH_LONG).show();
        } catch (IOException e) {
            Log.e("IOException", e.toString());
        } finally {
            try {
                fileOutputStream.close();
            } catch (IOException e) {
                Log.e("IOException", e.toString());
            }
        }

    }

}

Answer 1

简短的回答是，它取决于您正在编写的外部存储中的位置以及您如何获取路径。每个应用都可以访问自己的＆＃34;私有＆＃34;外部存储和外部缓存区域，无需特殊权限。您可以分别通过Context.getExternalFilesDir()和Context.getExternalCacheDir()访问路径。

另一方面，如果您想在外部存储设备中的任何其他位置写入内容，例如通过调用Environment.getExternalStorageDirectory()获取的路径，则需要保留WRITE_EXTERNAL_STORAGE权限。即使这样，当您开始使用辅助外部存储时，也存在一些时髦的限制。

Android M及以上存储空间权限问题

1 个答案: