Question

if (Build.VERSION.SDK_INT >= 23) {
    if (checkPermission()) {
        Log.e("permission", "Permission already granted.");
    } else {
        requestPermission();
    }
}

private boolean checkPermission() {
    int result = ContextCompat.checkSelfPermission(SolutionBrouchereActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE);
    if (result == PackageManager.PERMISSION_GRANTED) {
        viewOrDownloadPDF();
        return true;
    } else {
        return false;
    }
}

private void requestPermission() {
    ActivityCompat.requestPermissions(getParent(), new String[]{Manifest.permission.CAMERA}, PERMISSION_REQUEST_CODE);
}

在初始屏幕上拒绝权限并且无法在其他活动中打开权限提示对话框后，此功能不起作用。

Answer 1

如果用户未在初始屏幕上授予权限，则可以在新的shouldShowRequestPermissionRationale中调用Activity方法。

参考： https://developer.android.com/training/permissions/requesting

Answer 2

如果您的target SDK version is >=23，则需要在运行时请求权限。否则，Android将不会像旧版Android一样请求许可。

在这种情况下，如果您转到Settings > Apps > "Your app" > Permissions，应该可以看到没有授予任何权限。

如果您不想询问权限，可以将目标sdk版本降低到22，以获取旧的权限系统。不过，您仍然可以使用sdk 23版进行编译。

因此对于> = 23，请使用以下代码：

此代码将自动检测应显示哪个对话框，因为android中显示该权限对话框有特定限制。如果尝试了特定次数，则不会显示权限对话框，我们将不得不自行将用户移至其设置。

此代码将帮助您实现两种情况：

CustomPermissionManager.java：

public class CustomPermissionManager {
    public static final int STORAGE_PERMISSION = 8;
    public HashMap<Integer, ArrayList<PermissionManagerUtil.OnPermissionInterface>> onPermissionInterfaces = new HashMap<>();
    public HashMap<Integer, Boolean> hasAlreadyAskedPermission = new HashMap<>();
    private MainActivity context;

    public void init(MainActivity context) {
        this.context = context;
    }

    private boolean isAskedForFirstTime(String permissionName) {
        if (!PreferenceManager.getDefaultSharedPreferences(context).getBoolean(permissionName, false)) {
            PreferenceManager.getDefaultSharedPreferences(context).edit().putBoolean(permissionName, true).commit();
            return true;
        }
        return false;
    }


    public void requestStoragePermission(Activity activity, boolean showAlertForSettingsIfNeeded, PermissionManagerUtil.OnPermissionInterface onPermissionInterface) {
        if (PermissionManagerUtil.instance.checkStoragePermission()) {
            onPermissionInterface.onPermissionGranted();
            return;
        }
        boolean isAskedFirstTime = isAskedForFirstTime(Manifest.permission.READ_EXTERNAL_STORAGE);

        if (showAlertForSettingsIfNeeded && !isAskedFirstTime && !ActivityCompat.shouldShowRequestPermissionRationale(activity, Manifest.permission.READ_EXTERNAL_STORAGE)) {
            // if user clicked on "never ask again" then popup will not show by android
            //https://stackoverflow.com/questions/33224432/android-m-anyway-to-know-if-a-user-has-chosen-never-to-show-the-grant-permissi
            showAlertDialogWithAppSettings(activity, Manifest.permission.READ_EXTERNAL_STORAGE);
        } else {

            if (onPermissionInterfaces.get(STORAGE_PERMISSION) == null) {
                onPermissionInterfaces.put(STORAGE_PERMISSION, new ArrayList<>());
            }
            if (onPermissionInterface != null) {
                onPermissionInterfaces.get(STORAGE_PERMISSION).add(onPermissionInterface);
            }
            if (!hasAlreadyAskedPermission.containsKey(STORAGE_PERMISSION)) {
                hasAlreadyAskedPermission.put(STORAGE_PERMISSION, true);
                ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, STORAGE_PERMISSION);
            }
        }
    }

    private void callPermissionManagerCallBack(int requestCode, int[] grantResults) {
        if (onPermissionInterfaces.containsKey(requestCode) && onPermissionInterfaces.get(requestCode) != null) {
            for (PermissionManagerUtil.OnPermissionInterface onPermissionInterface : onPermissionInterfaces.get(requestCode)) {
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    onPermissionInterface.onPermissionGranted();
                } else {
                    onPermissionInterface.onPermissionNotGranted();
                }
            }
            hasAlreadyAskedPermission.remove(requestCode);
            onPermissionInterfaces.get(requestCode).clear();
        }

    }


    private void showAlertDialogWithAppSettings(String permission) {
        showAlertDialogWithAppSettings(context, permission);
    }

    @SuppressLint("RestrictedApi")
    private void showAlertDialogWithAppSettings(Activity context, String permission) {

        String title = "Allow permissions";
        String message = "Please allow this permission to enable this feature.";
        switch (permission) {
            case Manifest.permission.WRITE_EXTERNAL_STORAGE:
                title = "Allow Storage Permission";
                message = "Please allow permission to do.... task";
                break;
        }

        AlertDialog.Builder builder = new AlertDialog.Builder(context);

        builder.setTitle(title);

        builder.setMessage(message);
        builder.setPositiveButton("Go to settings", (dialog, which) -> {
            Intent intent = new Intent();
            intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            Uri uri = Uri.fromParts("package", context.getPackageName(), null);
            intent.setData(uri);
            context.startActivity(intent);
        });
        builder.setNegativeButton("Cancel", (dialog, which) -> dialog.dismiss());
        builder.show();
    }


    public boolean checkStoragePermission() {
        int resultExternalStorage = PermissionChecker.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE);
        return resultExternalStorage == PackageManager.PERMISSION_GRANTED;
    }
}

这样称呼：

    CustomPermissionManager customPermissionManager = new CustomPermissionManager();
    customPermissionManager.init(context);
    customPermissionManager.requestCameraPermission(true, new OnPermissionInterface() {
        @Override
        public void onPermissionGranted() {

            //permission granted
    viewOrDownloadPDF();

        }

        @Override
        public void onPermissionNotGranted() {

            // permission not granted
        }


    });

// To check permission is given or not
        boolean isGranted =  customPermissionManager.checkStoragePermission();

您将来也可以添加其他权限，例如通过添加相同类型的方法来添加STORAGE_PERMISSION。

Answer 3

将此功能放在通用文件中，并在每次使用时调用都会再次检查

public static boolean checkPermission(final Activity context)
    {
        int currentAPIVersion = Build.VERSION.SDK_INT;
        if(currentAPIVersion>=android.os.Build.VERSION_CODES.M)
        {
            if (ContextCompat.checkSelfPermission(context, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED||ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) { //||ContextCompat.checkSelfPermission(context, Manifest.permission.CALL_PHONE)!=PackageManager.PERMISSION_GRANTED
                if (ActivityCompat.shouldShowRequestPermissionRationale(context, Manifest.permission.READ_EXTERNAL_STORAGE)||ActivityCompat.shouldShowRequestPermissionRationale(context, Manifest.permission.WRITE_EXTERNAL_STORAGE)||ActivityCompat.shouldShowRequestPermissionRationale(context, Manifest.permission.CALL_PHONE)) {
                    AlertDialog.Builder alertBuilder = new AlertDialog.Builder(context);
                    alertBuilder.setCancelable(true);
                    alertBuilder.setTitle("Permission necessary");
                    alertBuilder.setMessage("External storage permission is necessary");
                    alertBuilder.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                        @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
                        public void onClick(DialogInterface dialog, int which) {
                            ActivityCompat.requestPermissions(context, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE,Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.CALL_PHONE}, MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
                        }
                    });
                    AlertDialog alert = alertBuilder.create();
                    alert.show();
                } else {
                    ActivityCompat.requestPermissions(context, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE,Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.CALL_PHONE}, MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
                }
                return false;
            } else {
                return true;
            }
        } else {
            return true;
        }
    }

在“启动画面”上拒绝权限，但再次要求在另一活动中提示允许权限

3 个答案: