PermissionsDispatcher使用詳解

PermissionsDispatcher是一個基於注解、幫助開發者簡單處理Android 6.0系統中的運行時權限的開源庫。避免了開發者編寫大量繁瑣的樣板代碼。

開源地址：https://github.com/hotchemi/PermissionsDispatcher

文檔介紹：http://hotchemi.github.io/PermissionsDispatcher/

下面詳細介紹一下如何在Android Studio上使用該開源庫。

1、添加依賴

首先在項目工程下的build.gradle文件中加入對maven倉庫依賴引入的支持。

allprojects {
    repositories {
        jcenter()
        mavenCentral()
    }
}

之后在module下的build.gradle文件中添加兩項依賴：

compile 'com.github.hotchemi:permissionsdispatcher:2.3.1'
annotationProcessor 'com.github.hotchemi:permissionsdispatcher-processor:2.3.1'

並將targetSdkVersion設為23，即：targetSdkVersion 23

2、在Activity或Fragment中使用

注解列表：

Annotation	Required	Description
@RuntimePermissions	✓	注解在其內部需要使用運行時權限的Activity或Fragment上
@NeedsPermission	✓	注解在需要調用運行時權限的方法上，當用戶給予權限時會執行該方法
@OnShowRationale		注解在用於向用戶解釋為什么需要調用該權限的方法上，只有當第一次請求權限被用戶拒絕，下次請求權限之前會調用
@OnPermissionDenied		注解在當用戶拒絕了權限請求時需要調用的方法上
@OnNeverAskAgain		注解在當用戶選中了授權窗口中的不再詢問復選框后並拒絕了權限請求時需要調用的方法，一般可以向用戶解釋為何申請此權限，並根據實際需求決定是否再次彈出權限請求對話框

注意：被注解的方法不能是私有方法。

只有@RuntimePermissions和@NeedsPermission是必須的，其余注解均為可選。當使用了@RuntimePermissions和@NeedsPermission之后，需要點擊菜單欄中Build菜單下的Make Project，或者按快捷鍵Ctrl + F9編譯整個項目，編譯器會在app\build\intermediates\classes\debug目錄下與被注解的Activity同一個包下生成一個輔助類，名稱為被注解的Activity名稱+PermissionsDispatcher.class，如圖所示：

接下來可以調用輔助類里面的方法完成應用的權限請求了。

在需要調用權限的位置調用輔助類里面的xxxWithCheck方法，xxx是被@NeedsPermission注解的方法名。如：

MainActivityPermissionsDispatcher.showCameraWithCheck(this);

之后，還需要重寫該Activity的onRequestPermissionsResult()方法，其方法內調用輔助類的onRequestPermissionsResult()方法，如下：

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    // NOTE: delegate the permission handling to generated method
    MainActivityPermissionsDispatcher.onRequestPermissionsResult(this, requestCode, grantResults);
}

完整的MainActivity如下所示。

• MainActivity.java

@RuntimePermissions
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.button_camera).setOnClickListener(this);
        findViewById(R.id.button_contacts).setOnClickListener(this);
    }

    @Override
    public void onClick(@NonNull View v) {
        switch (v.getId()) {
            case R.id.button_camera:
                // NOTE: delegate the permission handling to generated method
                MainActivityPermissionsDispatcher.showCameraWithCheck(this);
                break;
            case R.id.button_contacts:
                // NOTE: delegate the permission handling to generated method
                MainActivityPermissionsDispatcher.showContactsWithCheck(this);
                break;
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        // NOTE: delegate the permission handling to generated method
        MainActivityPermissionsDispatcher.onRequestPermissionsResult(this, requestCode, grantResults);
    }

    @NeedsPermission(Manifest.permission.CAMERA)
    void showCamera() {
        // NOTE: Perform action that requires the permission. If this is run by PermissionsDispatcher, the permission will have been granted
        getSupportFragmentManager().beginTransaction()
                .replace(R.id.sample_content_fragment, CameraPreviewFragment.newInstance())
                .addToBackStack("camera")
                .commitAllowingStateLoss();
    }

    @NeedsPermission({Manifest.permission.READ_CONTACTS, Manifest.permission.WRITE_CONTACTS})
    void showContacts() {
        // NOTE: Perform action that requires the permission.
        // If this is run by PermissionsDispatcher, the permission will have been granted
        getSupportFragmentManager().beginTransaction()
                .replace(R.id.sample_content_fragment, ContactsFragment.newInstance())
                .addToBackStack("contacts")
                .commitAllowingStateLoss();
    }

    @OnShowRationale(Manifest.permission.CAMERA)
    void showRationaleForCamera(PermissionRequest request) {
        // NOTE: Show a rationale to explain why the permission is needed, e.g. with a dialog.
        // Call proceed() or cancel() on the provided PermissionRequest to continue or abort
        showRationaleDialog(R.string.permission_camera_rationale, request);
    }

    @OnShowRationale({Manifest.permission.READ_CONTACTS, Manifest.permission.WRITE_CONTACTS})
    void showRationaleForContact(PermissionRequest request) {
        // NOTE: Show a rationale to explain why the permission is needed, e.g. with a dialog.
        // Call proceed() or cancel() on the provided PermissionRequest to continue or abort
        showRationaleDialog(R.string.permission_contacts_rationale, request);
    }

    @OnPermissionDenied(Manifest.permission.CAMERA)
    void onCameraDenied() {
        // NOTE: Deal with a denied permission, e.g. by showing specific UI
        // or disabling certain functionality
        Toast.makeText(this, R.string.permission_camera_denied, Toast.LENGTH_SHORT).show();
    }

    @OnNeverAskAgain(Manifest.permission.CAMERA)
    void onCameraNeverAskAgain() {
        Toast.makeText(this, R.string.permission_camera_never_askagain, Toast.LENGTH_SHORT).show();
    }

    public void onBackClick(View view) {
        getSupportFragmentManager().popBackStack();
    }

    private void showRationaleDialog(@StringRes int messageResId, final PermissionRequest request) {
        new AlertDialog.Builder(this)
                .setPositiveButton("允許", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(@NonNull DialogInterface dialog, int which) {
                        request.proceed();
                    }
                })
                .setNegativeButton("拒絕", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(@NonNull DialogInterface dialog, int which) {
                        request.cancel();
                    }
                })
                .setCancelable(false)
                .setMessage(messageResId)
                .show();
    }
}

3、附：危險權限和權限組列表

Android官方文檔：https://developer.android.com/guide/topics/security/permissions.html#normal-dangerous

摘錄如下：

權限組	權限
CALENDAR	READ_CALENDAR WRITE_CALENDAR
CAMERA	CAMERA
CONTACTS	READ_CONTACTS WRITE_CONTACTS GET_ACCOUNTS
LOCATION	ACCESS_FINE_LOCATION ACCESS_COARSE_LOCATION
PHONE	READ_PHONE_STATE CALL_PHONE READ_CALL_LOG WRITE_CALL_LOG ADD_VOICEMAIL USE_SIP PROCESS_OUTGOING_CALLS
SENSORS	BODY_SENSORS
SMS	SEND_SMS RECEIVE_SMS READ_SMS RECEIVE_WAP_PUSH RECEIVE_MMS
STORAGE	READ_EXTERNAL_STORAGE WRITE_EXTERNAL_STORAGE

4、附：Demo下載

http://download.csdn.net/detail/u012939909/9722890