我在Android m中写了一个权限请求的简写，这段代码还处理了对旧Android版本的向后兼容性。

所有丑陋的代码都被提取到一个片段中，该片段将自己附加到请求权限的活动上。PermissionRequestManager的使用方法如下:

new PermissionRequestManager()
        // We need a AppCompatActivity here, if you are not using support libraries you will have to slightly change 
        // the PermissionReuqestManager class
        .withActivity(this)

        // List all permissions you need
        .withPermissions(android.Manifest.permission.CALL_PHONE, android.Manifest.permission.READ_CALENDAR)

        // This Runnable is called whenever the request was successfull
        .withSuccessHandler(new Runnable() {
            @Override
            public void run() {
                // Do something with your permissions!
                // This is called after the user has granted all 
                // permissions, we are one a older platform where 
                // the user does not need to grant permissions 
                // manually, or all permissions are already granted

            }
        })

        // Optional, called when the user did not grant all permissions
        .withFailureHandler(new Runnable() {
            @Override
            public void run() {
                // This is called if the user has rejected one or all of the requested permissions
                L.e(this.getClass().getSimpleName(), "Unable to request permission");

            }
        })

        // After calling this, the user is prompted to grant the rights
        .request();

来看看:https://gist.github.com/crysxd/385b57d74045a8bd67c4110c34ab74aa

为了准确地回答这个问题，当用户按下“永不再问”时会发生什么?

重写的方法/函数

onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray)

grantResult数组显示为空，你可以在这里做些什么?但不是最好的做法。

如何处理“永不再问”?

我正在使用Fragment，它需要READ_EXTERNAL_STORAGE权限。

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        when {
            isReadPermissionsGranted() -> {

                /**
                 * Permissions has been Granted
                 */

                getDirectories()
            }

            isPermissionDeniedBefore() -> {

                /**
                 * User has denied before, explain why we need the permission and ask again
                 */

                updateUIForDeniedPermissions()
                checkIfPermissionIsGrantedNow()

            }
            else -> {

                /**
                 * Need to ask For Permissions, First Time
                 */

                checkIfPermissionIsGrantedNow()

                /**
                 * If user selects, "Dont Ask Again" it will never ask again! so just update the UI for Denied Permissions
                 */

                updateUIForDeniedPermissions()

            }
        }
    }

其他的函数是微不足道的。

// Is Read Write Permissions Granted
fun isReadWritePermissionGranted(context: Context): Boolean {
    return (ContextCompat.checkSelfPermission(
        context as Activity,
        Manifest.permission.READ_EXTERNAL_STORAGE
    ) == PackageManager.PERMISSION_GRANTED) and
            (ContextCompat.checkSelfPermission(
                context,
                Manifest.permission.WRITE_EXTERNAL_STORAGE
            ) == PackageManager.PERMISSION_GRANTED)
}

fun isReadPermissionDenied(context: Context) : Boolean {
    return ActivityCompat.shouldShowRequestPermissionRationale(
        context as Activity,
        PermissionsUtils.READ_EXTERNAL_STORAGE_PERMISSIONS)
}

试试这个简单的权限库。它将在3个简单的步骤中处理与权限相关的所有操作。这节省了我的时间。您可以在15分钟内完成所有权限相关的工作。

它可以处理拒绝，它可以处理永不再请求，它可以调用应用程序设置的权限，它可以给出一个Rational消息，它可以给出一个拒绝消息，它可以给出一个接受的权限列表，它可以给出一个拒绝的权限列表，等等。

https://github.com/ParkSangGwon/TedPermission

步骤1:添加依赖项

dependencies {
     compile 'gun0912.ted:tedpermission:2.1.1'
     //check the above link for latest libraries
}

步骤2:征求许可

TedPermission.with(this)
    .setPermissionListener(permissionlistener)
    .setDeniedMessage("If you reject permission,you can not use this service\n\nPlease turn on permissions at [Setting] > [Permission]")
    .setPermissions(Manifest.permission.READ_CONTACTS, Manifest.permission.ACCESS_FINE_LOCATION)
    .check();

步骤3:处理权限响应

PermissionListener permissionlistener = new PermissionListener() {
    @Override
    public void onPermissionGranted() {
        Toast.makeText(MainActivity.this, "Permission Granted", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onPermissionDenied(ArrayList<String> deniedPermissions) {
        Toast.makeText(MainActivity.this, "Permission Denied\n" + deniedPermissions.toString(), Toast.LENGTH_SHORT).show();
    }
};

对每一种许可情况的完整解释

/**
 *    Case 1: User doesn't have permission
 *    Case 2: User has permission
 *
 *    Case 3: User has never seen the permission Dialog
 *    Case 4: User has denied permission once but he din't clicked on "Never Show again" check box
 *    Case 5: User denied the permission and also clicked on the "Never Show again" check box.
 *    Case 6: User has allowed the permission
 *
 */
public void handlePermission() {
    if (ContextCompat.checkSelfPermission(MainActivity.this,
            Manifest.permission.WRITE_EXTERNAL_STORAGE)
            != PackageManager.PERMISSION_GRANTED) {
        // This is Case 1. Now we need to check further if permission was shown before or not

        if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)) {

            // This is Case 4.
        } else {
            // This is Case 3. Request for permission here
        }

    } else {
        // This is Case 2. You have permission now you can do anything related to it
    }
}

public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {

    if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        // This is Case 2 (Permission is now granted)
    } else {
        // This is Case 1 again as Permission is not granted by user

        //Now further we check if used denied permanently or not
        if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            // case 4 User has denied permission but not permanently

        } else {
            // case 5. Permission denied permanently.
            // You can open Permission setting's page from here now.
        }

    }
}

一个有用的函数来确定任意权限是否被阻止请求(在Kotlin中):

private fun isPermissionBlockedFromAsking(activity: Activity, permission: String): Boolean {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        return ContextCompat.checkSelfPermission(activity, permission) != PackageManager.PERMISSION_GRANTED
            && !activity.shouldShowRequestPermissionRationale(permission)
            && PreferenceManager.getDefaultSharedPreferences(activity).getBoolean(permission, false)
    }
    return false
}

当你第一次请求一个权限时，需要设置一个共享首选项布尔值为true，其中包含你想要的权限名称(例如android.Manifest.permission.READ_PHONE_STATE)。

解释:

Build.VERSION。SDK_INT >= Build.VERSION_CODES。因为有些代码只能在API级别23+上运行。

ContextCompat。checkSelfPermission(activity, permission) != PackageManager。permission_granting检查我们还没有权限。

activity.shouldShowRequestPermissionRationale(permission)来检查用户是否再次拒绝了应用程序的请求。由于这个函数的特性，还需要下面这行代码。

PreferenceManager.getDefaultSharedPreferences(活动)。getBoolean(permission, false)用于区分“Never asked”和“Never ask again”状态(以及在第一次权限请求时将值设置为true)，因为前一行不会返回此信息。

shouldShowRequestPermissionRationale()方法可以用来检查用户是否选择了“never asked again”选项并拒绝了权限。 有很多代码示例，所以我宁愿解释如何将它用于这样的目的，因为我认为它的名称和实现使它比实际情况更加复杂。

正如在运行时请求权限中解释的那样，如果选项“never ask again”可见，该方法返回true，否则返回false;因此，它在第一次显示对话框时返回false，然后从第二次开始返回true，只有当用户拒绝选择该选项的权限时，它才会再次返回false。

要检测这种情况，您可以检测序列false-true-false，或者(更简单)您可以使用一个标记来跟踪对话框显示的初始时间。在此之后，该方法返回true或false，其中false将允许您检测何时选择该选项。