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

你可以在onRequestPermissionsResult()中检查shouldShowRequestPermissionRationale()。

https://youtu.be/C8lUdPVSzDk?t=2m23s

在onRequestPermissionsResult()中检查权限是否被授予。如果不是,检查shouldShowRequestPermissionRationale()。

如果此方法返回true,则说明为什么需要此特定权限。然后根据用户的选择再次请求permissions()。 如果它返回false,则显示一个错误消息,权限未授予,应用程序不能继续前进或特定功能被禁用。

下面是示例代码。

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode) {
        case STORAGE_PERMISSION_REQUEST:
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // permission was granted :)
                downloadFile();
            } else {
                // permission was not granted
                if (getActivity() == null) {
                    return;
                }
                if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                    showStoragePermissionRationale();
                } else {
                    Snackbar snackbar = Snackbar.make(getView(), getResources().getString(R.string.message_no_storage_permission_snackbar), Snackbar.LENGTH_LONG);
                    snackbar.setAction(getResources().getString(R.string.settings), new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                            if (getActivity() == null) {
                                return;
                            }
                            Intent intent = new Intent();
                            intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                            Uri uri = Uri.fromParts("package", getActivity().getPackageName(), null);
                            intent.setData(uri);
                            OrderDetailFragment.this.startActivity(intent);
                        }
                    });
                    snackbar.show();
                }
            }
            break;
    }
}

显然,谷歌maps对位置许可正是这样做的。

其他回答

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.
        }

    }
}

可能对某人有用:——

我注意到的是,如果我们在onRequestPermissionsResult()回调方法中检查shouldshowrequestpermissionration理()标志,它只显示两种状态。

状态1:-返回true:——任何时候用户单击Deny permissions(包括第一次)。

状态2:-返回false:-如果用户选择“永不再问”。

详细工作实例链接

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。

我也遇到过同样的问题,但我解决了。为了简化工作,我编写了一个util类来处理运行时权限。

public class PermissionUtil {
    /*
    * Check if version is marshmallow and above.
    * Used in deciding to ask runtime permission
    * */
    public static boolean shouldAskPermission() {
        return (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M);
    }
private static boolean shouldAskPermission(Context context, String permission){
        if (shouldAskPermission()) {
            int permissionResult = ActivityCompat.checkSelfPermission(context, permission);
            if (permissionResult != PackageManager.PERMISSION_GRANTED) {
                return true;
            }
        }
        return false;
    }
public static void checkPermission(Context context, String permission, PermissionAskListener listener){
/*
        * If permission is not granted
        * */
        if (shouldAskPermission(context, permission)){
/*
            * If permission denied previously
            * */
            if (((Activity)context).shouldShowRequestPermissionRationale(permission)) {
                listener.onPermissionPreviouslyDenied();
            } else {
                /*
                * Permission denied or first time requested
                * */
if (PreferencesUtil.isFirstTimeAskingPermission(context, permission)) {
                    PreferencesUtil.firstTimeAskingPermission(context, permission, false);
                    listener.onPermissionAsk();
                } else {
                    /*
                    * Handle the feature without permission or ask user to manually allow permission
                    * */
                    listener.onPermissionDisabled();
                }
            }
        } else {
            listener.onPermissionGranted();
        }
    }
/*
    * Callback on various cases on checking permission
    *
    * 1.  Below M, runtime permission not needed. In that case onPermissionGranted() would be called.
    *     If permission is already granted, onPermissionGranted() would be called.
    *
    * 2.  Above M, if the permission is being asked first time onPermissionAsk() would be called.
    *
    * 3.  Above M, if the permission is previously asked but not granted, onPermissionPreviouslyDenied()
    *     would be called.
    *
    * 4.  Above M, if the permission is disabled by device policy or the user checked "Never ask again"
    *     check box on previous request permission, onPermissionDisabled() would be called.
    * */
    public interface PermissionAskListener {
/*
        * Callback to ask permission
        * */
        void onPermissionAsk();
/*
        * Callback on permission denied
        * */
        void onPermissionPreviouslyDenied();
/*
        * Callback on permission "Never show again" checked and denied
        * */
        void onPermissionDisabled();
/*
        * Callback on permission granted
        * */
        void onPermissionGranted();
    }
}

PreferenceUtil方法如下。

public static void firstTimeAskingPermission(Context context, String permission, boolean isFirstTime){
SharedPreferences sharedPreference = context.getSharedPreferences(PREFS_FILE_NAME, MODE_PRIVATE;
 sharedPreference.edit().putBoolean(permission, isFirstTime).apply();
 }
public static boolean isFirstTimeAskingPermission(Context context, String permission){
return context.getSharedPreferences(PREFS_FILE_NAME, MODE_PRIVATE).getBoolean(permission, true);
}

现在,您所需要的就是使用带有适当参数的方法* checkPermission*。

举个例子,

PermissionUtil.checkPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE,
                    new PermissionUtil.PermissionAskListener() {
                        @Override
                        public void onPermissionAsk() {
                            ActivityCompat.requestPermissions(
                                    thisActivity,
              new String[]{Manifest.permission.READ_CONTACTS},
                            REQUEST_EXTERNAL_STORAGE
                            );
                        }
@Override
                        public void onPermissionPreviouslyDenied() {
                       //show a dialog explaining permission and then request permission
                        }
@Override
                        public void onPermissionDisabled() {
Toast.makeText(context, "Permission Disabled.", Toast.LENGTH_SHORT).show();
                        }
@Override
                        public void onPermissionGranted() {
                            readContacts();
                        }
                    });

我的应用程序如何知道用户是否选中了“永不再问”?

如果用户勾选“永不再问”,你将得到onPermissionDisabled上的回调。

快乐编码:)

请不要为这个解决办法向我扔石头。

这是可行的,但有点“俗气”。

当调用requestPermissions时,注册当前时间。

        mAskedPermissionTime = System.currentTimeMillis();

然后在onRequestPermissionsResult中

如果结果不允许,请再次检查时间。

 if (System.currentTimeMillis() - mAskedPermissionTime < 100)

由于用户不可能那么快地点击拒绝按钮,我们知道他选择了“永不再问”,因为回调是即时的。

使用风险自负。