根据这个:http://developer.android.com/preview/features/runtime-permissions.html#coding一个应用程序可以检查运行时权限和请求权限,如果它还没有被授予。弹出如下对话框:

如果用户拒绝一个重要的权限,在我看来,应用程序应该显示一个解释为什么需要权限和什么影响拒绝。该对话框有两个选项:

重试(再次请求许可) 拒绝(应用程序将工作没有该许可)。

但是,如果用户选中“Never ask again”,则不应该显示带有解释的第二个对话框,特别是如果用户之前已经拒绝了一次。 现在的问题是:我的应用程序如何知道用户是否选中了Never ask again?IMO onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults)没有给我这个信息。

第二个问题是:谷歌是否计划在权限对话框中包含一个自定义消息,以解释为什么应用程序需要权限?这样就不会出现第二个对话框,这肯定会带来更好的用户体验。


当前回答

这里有一个很好的和简单的方法来检查当前的权限状态:

    @Retention(RetentionPolicy.SOURCE)
    @IntDef({GRANTED, DENIED, BLOCKED_OR_NEVER_ASKED })
    public @interface PermissionStatus {}

    public static final int GRANTED = 0;
    public static final int DENIED = 1;
    public static final int BLOCKED_OR_NEVER_ASKED = 2;

    @PermissionStatus 
    public static int getPermissionStatus(Activity activity, String androidPermissionName) {
        if(ContextCompat.checkSelfPermission(activity, androidPermissionName) != PackageManager.PERMISSION_GRANTED) {
            if(!ActivityCompat.shouldShowRequestPermissionRationale(activity, androidPermissionName)){
                return BLOCKED_OR_NEVER_ASKED;
            }
            return DENIED;
        }
        return GRANTED;
    }

警告:在用户通过用户提示接受/拒绝权限之前,在第一个应用程序启动时返回BLOCKED_OR_NEVER_ASKED(在sdk 23+设备上)

更新:

Android支持库现在似乎也有一个非常类似的类Android .support.v4.content。PermissionChecker,包含checkSelfPermission(),返回:

public static final int PERMISSION_GRANTED = 0;
public static final int PERMISSION_DENIED = -1;
public static final int PERMISSION_DENIED_APP_OP = -2;

其他回答

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)
}

我必须实现相机的动态权限。有三种可能的情况:允许2。否认,3。别再问了。

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

    for (String permission : permissions) {
        if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(), permission)) {
            //denied
            Log.e("denied", permission);
        } else {
            if (ActivityCompat.checkSelfPermission(getActivity(), permission) == PackageManager.PERMISSION_GRANTED) {
                //allowed
                Log.e("allowed", permission);
            } else {
                //set to never ask again
                Log.e("set to never ask again", permission);
                //do something here.
            }
        }
    }
    if (requestCode != MaterialBarcodeScanner.RC_HANDLE_CAMERA_PERM) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        return;
    }
    if (grantResults.length != 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        mScannerView.setResultHandler(this);
        mScannerView.startCamera(mCameraId);
        mScannerView.setFlash(mFlash);
        mScannerView.setAutoFocus(mAutoFocus);
        return;
    } else {
        //set to never ask again
        Log.e("set to never ask again", permissions[0]);
    }
    DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            dialog.cancel();
        }
    };
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    builder.setTitle("Error")
            .setMessage(R.string.no_camera_permission)
            .setPositiveButton(android.R.string.ok, listener)
            .show();


}

private void insertDummyContactWrapper() {
        int hasWriteContactsPermission = checkSelfPermission(Manifest.permission.CAMERA);
        if (hasWriteContactsPermission != PackageManager.PERMISSION_GRANTED) {
            requestPermissions(new String[]{Manifest.permission.CAMERA},
                    REQUEST_CODE_ASK_PERMISSIONS);
            return;
        }
        mScannerView.setResultHandler(this);
        mScannerView.startCamera(mCameraId);
        mScannerView.setFlash(mFlash);
        mScannerView.setAutoFocus(mAutoFocus);
    }

private int checkSelfPermission(String camera) {
    if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.CAMERA)
            != PackageManager.PERMISSION_GRANTED) {
        return REQUEST_CODE_ASK_PERMISSIONS;
    } else {
        return REQUEST_NOT_CODE_ASK_PERMISSIONS;
    }
}

您可以通过检查权限原理是否显示在onRequestPermissionsResult()回调方法中来确定它。如果您发现任何权限集永远不会再次请求,您可以请求用户从设置中授予权限。

我的完整实现如下所示。它适用于单个或多个权限请求。使用以下或直接使用我的库。

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    if(permissions.length == 0){
        return;
    }
    boolean allPermissionsGranted = true;
    if(grantResults.length>0){
        for(int grantResult: grantResults){
            if(grantResult != PackageManager.PERMISSION_GRANTED){
                allPermissionsGranted = false;
                break;
            }
        }
    }
    if(!allPermissionsGranted){
        boolean somePermissionsForeverDenied = false;
        for(String permission: permissions){
            if(ActivityCompat.shouldShowRequestPermissionRationale(this, permission)){
                //denied
                Log.e("denied", permission);
            }else{
                if(ActivityCompat.checkSelfPermission(this, permission) == PackageManager.PERMISSION_GRANTED){
                    //allowed
                    Log.e("allowed", permission);
                } else{
                    //set to never ask again
                    Log.e("set to never ask again", permission);
                    somePermissionsForeverDenied = true;
                }
            }
        }
        if(somePermissionsForeverDenied){
            final AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
            alertDialogBuilder.setTitle("Permissions Required")
                    .setMessage("You have forcefully denied some of the required permissions " +
                            "for this action. Please open settings, go to permissions and allow them.")
                    .setPositiveButton("Settings", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS,
                                    Uri.fromParts("package", getPackageName(), null));
                            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                            startActivity(intent);
                        }
                    })
                    .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                        }
                    })
                    .setCancelable(false)
                    .create()
                    .show();
        }
    } else {
        switch (requestCode) {
            //act according to the request code used while requesting the permission(s).
        }
    }
}

shouldShowRequestPermissionRationale根据之前权限请求中的用户首选项返回true或false。

如果用户只是拒绝权限(不是永远)shouldShowRequestPermissionRationale将返回true。如果永远拒绝许可,则返回false。窍门是即使用户允许了权限shouldShowRequestPermissionRationale也会返回false。

因此,我们可以结合这两个条件来得到永不再问的选择与否。

因此,如果用户不允许权限,并且shouldShowRequestPermissionRationale返回false,那么这意味着用户选择永远不会再次请求权限。

https://stackoverflow.com/a/58114769/5151336

你可以听漂亮。

侦听器

interface PermissionListener {
    fun onNeedPermission()
    fun onPermissionPreviouslyDenied(numberDenyPermission: Int)
    fun onPermissionDisabledPermanently(numberDenyPermission: Int)
    fun onPermissionGranted()
}

MainClass的权限

class PermissionUtil {

    private val PREFS_FILENAME = "permission"
    private val TAG = "PermissionUtil"

    private fun shouldAskPermission(context: Context, permission: String): Boolean {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            val permissionResult = ActivityCompat.checkSelfPermission(context, permission)
            if (permissionResult != PackageManager.PERMISSION_GRANTED) {
                return true
            }
        }
        return false
    }

    fun checkPermission(context: Context, permission: String, listener: PermissionListener) {

        Log.i(TAG, "CheckPermission for $permission")

        if (shouldAskPermission(context, permission)) {

            // Load history permission
            val sharedPreference = context.getSharedPreferences(PREFS_FILENAME, 0)
            val numberShowPermissionDialog = sharedPreference.getInt(permission, 0)

            if (numberShowPermissionDialog == 0) {

                (context as? Activity)?.let {
                    if (ActivityCompat.shouldShowRequestPermissionRationale(it, permission)) {
                        Log.e(TAG, "User has denied permission but not permanently")
                        listener.onPermissionPreviouslyDenied(numberShowPermissionDialog)
                    } else {
                        Log.e(TAG, "Permission denied permanently.")
                        listener.onPermissionDisabledPermanently(numberShowPermissionDialog)
                    }
                } ?: kotlin.run {
                    listener.onNeedPermission()
                }

            } else {
                // Is FirstTime
                listener.onNeedPermission()
            }


            // Save history permission
            sharedPreference.edit().putInt(permission, numberShowPermissionDialog + 1).apply()


        } else {
            listener.onPermissionGranted()
        }

    }
}

以这种方式使用

      PermissionUtil().checkPermission(this, Manifest.permission.ACCESS_FINE_LOCATION,
                object : PermissionListener {
                    override fun onNeedPermission() {
                        log("---------------------->onNeedPermission")

//                            ActivityCompat.requestPermissions(this@SplashActivity,
//                                    Array(1) { Manifest.permission.ACCESS_FINE_LOCATION },
//                                    118)

                    }

                    override fun onPermissionPreviouslyDenied(numberDenyPermission: Int) {
                        log("---------------------->onPermissionPreviouslyDenied")
                    }

                    override fun onPermissionDisabledPermanently(numberDenyPermission: Int) {
                        log("---------------------->onPermissionDisabled")
                    }

                    override fun onPermissionGranted() {
                        log("---------------------->onPermissionGranted")
                    }

                })

在activity或fragmnet中覆盖onRequestPermissionsResult

override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
 if (requestCode == 118) {
        if (permissions[0] == Manifest.permission.ACCESS_FINE_LOCATION && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            getLastLocationInMap()
        }
        }
    }