Android6.0 权限申请封装

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之前一篇博客初试了Android6.0系统的动态权限申请，成功之后开始思考将权限申请功能封装以供更加方便的调用。

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查阅6.0系统权限相关的API，整个权限申请需要调用三个方法：

1. ContextCompat.checkSelfPermission()
检查应用是否拥有该权限，被授权返回值为PERMISSION_GRANTED，否则返回PERMISSION_DENIED

   /**     * Determine whether <em>you</em> have been granted a particular permission.     *     * @param permission The name of the permission being checked.     *     * @return {@link android.content.pm.PackageManager#PERMISSION_GRANTED} if you have the     * permission, or {@link android.content.pm.PackageManager#PERMISSION_DENIED} if not.     *     * @see android.content.pm.PackageManager#checkPermission(String, String)     */    public static int checkSelfPermission(@NonNull Context context, @NonNull String permission) {        if (permission == null) {            throw new IllegalArgumentException("permission is null");        }        return context.checkPermission(permission, android.os.Process.myPid(), Process.myUid());    }

2、ActivityCompat.requestPermissions()

    /**     * Requests permissions to be granted to this application. These permissions     * must be requested in your manifest, they should not be granted to your app,     * and they should have protection level {@link android.content.pm.PermissionInfo     * #PROTECTION_DANGEROUS dangerous}, regardless whether they are declared by     * the platform or a third-party app.     * <p>     * Normal permissions {@link android.content.pm.PermissionInfo#PROTECTION_NORMAL}     * are granted at install time if requested in the manifest. Signature permissions     * {@link android.content.pm.PermissionInfo#PROTECTION_SIGNATURE} are granted at     * install time if requested in the manifest and the signature of your app matches     * the signature of the app declaring the permissions.     * </p>     * <p>     * If your app does not have the requested permissions the user will be presented     * with UI for accepting them. After the user has accepted or rejected the     * requested permissions you will receive a callback reporting whether the     * permissions were granted or not. Your activity has to implement {@link     * android.support.v4.app.ActivityCompat.OnRequestPermissionsResultCallback}     * and the results of permission requests will be delivered to its {@link     * android.support.v4.app.ActivityCompat.OnRequestPermissionsResultCallback#onRequestPermissionsResult(     * int, String[], int[])} method.     * </p>     * <p>     * Note that requesting a permission does not guarantee it will be granted and     * your app should be able to run without having this permission.     * </p>     * <p>     * This method may start an activity allowing the user to choose which permissions     * to grant and which to reject. Hence, you should be prepared that your activity     * may be paused and resumed. Further, granting some permissions may require     * a restart of you application. In such a case, the system will recreate the     * activity stack before delivering the result to your onRequestPermissionsResult(     * int, String[], int[]).     * </p>     * <p>     * When checking whether you have a permission you should use {@link     * #checkSelfPermission(android.content.Context, String)}.     * </p>     *     * @param activity The target activity.     * @param permissions The requested permissions.     * @param requestCode Application specific request code to match with a result     *    reported to {@link OnRequestPermissionsResultCallback#onRequestPermissionsResult(     *    int, String[], int[])}.     *     * @see #checkSelfPermission(android.content.Context, String)     * @see #shouldShowRequestPermissionRationale(android.app.Activity, String)     */    public static void requestPermissions(final @NonNull Activity activity,            final @NonNull String[] permissions, final int requestCode) {        if (Build.VERSION.SDK_INT >= 23) {            ActivityCompatApi23.requestPermissions(activity, permissions, requestCode);        } else if (activity instanceof OnRequestPermissionsResultCallback) {            Handler handler = new Handler(Looper.getMainLooper());            handler.post(new Runnable() {                @Override                public void run() {                    final int[] grantResults = new int[permissions.length];                    PackageManager packageManager = activity.getPackageManager();                    String packageName = activity.getPackageName();                    final int permissionCount = permissions.length;                    for (int i = 0; i < permissionCount; i++) {                        grantResults[i] = packageManager.checkPermission(                                permissions[i], packageName);                    }                    ((OnRequestPermissionsResultCallback) activity).onRequestPermissionsResult(                            requestCode, permissions, grantResults);                }            });        }    }

3、AppCompatActivity.onRequestPermissionsResult()
该方法类似于Activity的OnActivityResult()的回调方法，主要接收请求授权的返回值

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下面开始在项目中进行权限封装：
1、新建一个BaseActivity活动，extends自AppCompatActivity。这里将权限申请设计成基类，让项目中的所有活动都继承BaseActivity类。
延伸学习：关于extends和implements的区别参考

2、声明两个Map类型的变量，用于存放取得权限后的运行和未获取权限时的运行。
延伸学习：java中Map,List与Set的区别

    private Map<Integer, Runnable> allowablePermissionRunnables = new HashMap<>();    private Map<Integer, Runnable> disallowblePermissionRunnables = new HashMap<>();

3、实现requesPermission方法。

/**     * @param requestId            请求授权的Id，唯一即可     * @param permission           请求的授权     * @param allowableRunnable    同意授权后的操作     * @param disallowableRunnable 禁止授权后的操作     **/    protected void requestPermission(int requestId, String permission,                                     Runnable allowableRunnable, Runnable disallowableRunnable) {        if (allowableRunnable == null) {            throw new IllegalArgumentException("allowableRunnable == null");        }        allowablePermissionRunnables.put(requestId, allowableRunnable);        if (disallowableRunnable != null) {            disallowblePermissionRunnables.put(requestId, disallowableRunnable);        }        //版本判断        if (Build.VERSION.SDK_INT >= 23) {            //检查是否拥有权限            int checkPermission = ContextCompat.checkSelfPermission(MyApplication.getContext(), permission);            if (checkPermission != PackageManager.PERMISSION_GRANTED) {                //弹出对话框请求授权                ActivityCompat.requestPermissions(BaseActivity.this, new String[]{permission}, requestId);                return;            } else {                allowableRunnable.run();            }        } else {            allowableRunnable.run();        }    }

4、实现onRequestPermissionsResult方法。

 @Override    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {        super.onRequestPermissionsResult(requestCode, permissions, grantResults);        if (grantResults[0] == PackageManager.PERMISSION_GRANTED){            Runnable allowRun=allowablePermissionRunnables.get(requestCode);            allowRun.run();    }else {            Runnable disallowRun = disallowblePermissionRunnables.get(requestCode);            disallowRun.run();        }    }

5、调用

    public static final String CONTACT_PERMISSION = android.Manifest.permission.READ_CONTACTS;    public static final int readContactRequest = 1;  @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.content_get_contacts);        ContactsLv = (ListView) findViewById(R.id.ContactsLv);        adapter = new ContactsAdapter(list, this);        ContactsLv.setAdapter(adapter);        requestPermission(readContactRequest, CONTACT_PERMISSION, new Runnable() {            @Override            public void run() {                getContacts();            }        }, new Runnable() {            @Override            public void run() {                getContactsDenied();            }        });    }