Failing to request permissions in .NET MAUI - c#

Good day.
In all my applications, requesting user permissions is not showing the permissions popup in Android.
I am using the FileSaver in the .NET MAUI CommunityToolkit and as I understand, the SaveAsync method is supposed to ask for permission and save to disk.
async Task SaveDocument(MemoryStream memoryStream)
{
try
{
//var fileLocation = await FileSaver.Default.SaveAsync($"{Guid.NewGuid()}.docx", memoryStream, new CancellationToken());
var someLocation = await FileSaver.SaveAsync($"{Guid.NewGuid()}.docx", memoryStream, new CancellationToken());
await Toast.Make($"File is saved: {someLocation}").Show();
}
catch (Exception ex)
{
await Toast.Make($"File is not saved, {ex.Message}").Show();
}
}
The catch statement is being hit with error message permissions not granted.
Here is my AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
<application android:allowBackup="true" android:icon="#mipmap/appicon" android:roundIcon="#mipmap/appicon_round" android:supportsRtl="true">
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}.provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/file_paths" />
</provider>
</application>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
</manifest>
As such, I thought I would do it using Permission API in .NET MAUI as implemented below
public static async Task<bool> CheckForStoragePermission()
{
bool permitted = false;
var status = await Permissions.CheckStatusAsync<Permissions.StorageWrite>();
if (status == PermissionStatus.Granted)
permitted = true;
else
{
status = await Permissions.RequestAsync<Permissions.StorageWrite>();
}
return permitted;
}
In both cases, the permissions popup doesn't show up and it moves on with the code.
What am I doing wrong?


I have tested your code on the emulator with the Android 12.0 and Android 11.0. The two devices both worked and will show the the permissions popup.
Did you test your application on the Android 13.0? According to this issue about .NET MAUI does not work with Android 13 Android.permission.write_external_storage on the github. The maui project's default target android framework is Android 13.0(Api 33). And then if you set it on the device which is android 13.0. The storage permission popup will not show because the adnrodi 13.0 has removed this permission.
You can try the workaround in the issue which is adding <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="31" /> in the AndroidManifest.xml. You can also use the device which android version is 12.0 or lower to test your application.

Related

.net Maui camera throwing error about write external storage

Anyone worked out how to take a photo in Maui on android api 31 using MediaPicker?
Lots of people getting the same error as this but I haven’t found a solution yet. I believe this version of Android doesn’t have the same permissions and so MediaPicker doesn’t seem to work with it. As soon as I call the camera I get the following:
Error: Microsoft.Maui.ApplicationModel.PermissionException: 'StorageWrite permission was not granted: Denied'
Android.Manifest entries:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.ACTION_OPEN_DOCUMENT" />
<uses-permission android:name="android.permission.ACTION_OPEN_DOCUMENT_TREE" />
<uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
<uses-permission android:name="android.permission.READ_MEDIA_AUDIO" />
<uses-permission android:name="android.permission.READ_MEDIA_VIDEO" />
<!-- Required to maintain app compatibility. -->
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" android:maxSdkVersion="32" />
<uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
<queries>
<intent>
<action android:name="android.media.action.IMAGE_CAPTURE" />
</intent>
</queries>
Code:
private async void TakePhotoPressed()
{
MediaPickerOptions options = new MediaPickerOptions();
options.Title = "Add Attachment";
FileResult result = await MediaPicker.Default.CapturePhotoAsync(options);
...
}
Note that if I don't request StorageWrite permission I get the following error:
Microsoft.Maui.ApplicationModel.PermissionException: 'You need to declare using the permission: android.permission.WRITE_EXTERNAL_STORAGE in your AndroidManifest.xml'
So, bit of a catch 22 situation...
Thanks

searching nearby available bluetooth in Xamarin android 9

I want to search for available bluetooth but I can't find a solution that works in Xamarin android 9,

Firstly, add the following permissions to AndroidManifest.xml
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
And for Bluetooth scan you could use the plugin Plugin.BLE from Nuget .
Usage
ObservableCollection<Plugin.BLE.Abstractions.Contracts.IDevice> deviceList;
deviceList = new ObservableCollection<Plugin.BLE.Abstractions.Contracts.IDevice>();
var adapter = CrossBluetoothLE.Current.Adapter;
adapter.DeviceDiscovered += (s, a) =>
{
Console.WriteLine(a.Device.Name);
deviceList.Add(a.Device);
};
await adapter.StartScanningForDevicesAsync();
For more details and usage of the plugin you could check https://github.com/xabre/xamarin-bluetooth-le .

How to get provider authorities value from an Android manifest file programmatically in Xamarin Forms?

I'm developing an Android with Xamarin.Forms, and I'm using the AndroidManifest.xml file shown below.
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
android:versionCode="1" android:versionName="1.0">
<uses-sdk android:minSdkVersion="26" android:targetSdkVersion="26" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<application android:label="MyApp.Android">
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="myapp.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/provider_file_paths" />
</provider>
</application>
I'd like to get the android:authorities value of the provider directive (in my case "myapp.fileprovider" as string) programmatically.
How is this possible with Xamarin.Forms?

I found an answer.
var context = Android.App.Application.Context;
var component = new Android.Content.ComponentName(context, Java.Lang.Class.FromType(typeof(Android.Support.V4.Content.FileProvider)));
var info = context.PackageManager.GetProviderInfo(component, Android.Content.PM.PackageInfoFlags.MetaData);
var authority = info.Authority;
Kotlin version as a helper function
fun getFileProviderAuthorities(context: Context): String {
val component = ComponentName(context, FileProvider::class.java)
val info = context.packageManager.getProviderInfo(component, android.content.pm.PackageManager.GET_META_DATA)
return info.authority
}

AndroidRuntime Caused by: java.lang.ClassNotFoundException: Didn't find class "android.support.multidex.MultiDexApplication"

I have an issue with launching my app in Release mode.
I have enabled MultiDex for Debug and Release modes. When deploying in Debug mode, my app is working fine and everything OK. But when I launch it Release mode, it crashes at startup. Here's a Device Log:
Android manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
android:versionName="17.2" android:versionCode="1"
android:installLocation="auto" package="com.myapp">
<uses-sdk android:minSdkVersion="19" android:targetSdkVersion="28" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<application android:label="Test Application" android:largeHeap="true" android:icon="#drawable/AppIcon" android:supportsRtl="true">
<provider android:name="android.support.v4.content.FileProvider" android:authorities="${applicationId}.provider" android:exported="false" android:grantUriPermissions="true">
<meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="#xml/provider_paths" />
</provider>
</application>
</manifest>

Make your Application extend MultiDexApplication. If you don't have one already just create a BaseApplication class like so:
public class BaseApplication extends MultiDexApplication {
#Override
public void onCreate() {
super.onCreate();
}
#Override
protected void attachBaseContext(Context base) {
super.attachBaseContext(base);
MultiDex.install(this);
}
}
also, add the following to your build.gradle:
multiDexEnabled true
for your dependencies:
dependencies {
implementation 'androidx.multidex:multidex:2.0.1'
}
or if not using AndroidX
dependencies {
implementation 'com.android.support:multidex:1.0.3'
}
Finally in your manifest add within your application tag:
android:name="android.support.multidex.MultiDexApplication"
or
android:name="androidx.multidex.MultiDexApplication"
if you've migrated to AndroidX

Xamarin Forms File Provider not set

I am currently going through the process of Learning Xamarin.Forms. I am currently attempting to implement Camera functions using the Plugin.Media.CrossMedia library.
Implemented below:
public async Task<ImageSource> StartCamera()
{
await CrossMedia.Current.Initialize();
if (Plugin.Media.CrossMedia.Current.IsTakePhotoSupported && CrossMedia.Current.IsCameraAvailable)
{
var photo = await CrossMedia.Current.TakePhotoAsync(new StoreCameraMediaOptions() { SaveToAlbum=false, SaveMetaData=false});
if (photo != null)
return ImageSource.FromStream(() => { return photo.GetStream(); });
else
return null;
}
else
{
return null;
}
}
However upon executing the 'TakePhotoAsync' method I recieve the following error.
System.ArgumentException: Unable to get file location. This most likely means that the file provider information is not set in your Android Manifest file. Please check documentation on how to set this up in your project.
I have tried looking this up but to no avail. My AndroidManifest.xml file looks like this at the moment.
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="RCPTTracker.Android" android:versionCode="1" android:versionName="1.0">
<uses-sdk />
<application android:label="RCPTTracker.Android"></application>
</manifest>
My inkling is that I need to declare something in here, but I haven't been able to find what, and all tutorials i have followed don't go through anything with setting up a File Provider.
Any suggestions?

The readme says:
If your application targets Android N (API 24) or newer, you must use version 2.6.0+.
You must also add a few additional configuration files to adhere to the new strict mode:
1.) Add the following to your AndroidManifest.xml inside the tags:
<provider android:name="android.support.v4.content.FileProvider"
android:authorities="YOUR_APP_PACKAGE_NAME.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/file_paths"></meta-data>
</provider>
YOUR_APP_PACKAGE_NAME must be set to your app package name!
2.) Add a new folder called xml into your Resources folder and add a new XML file called file_paths.xml
Add the following code:
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-files-path name="my_images" path="Pictures" />
<external-files-path name="my_movies" path="Movies" />
</paths>
YOUR_APP_PACKAGE_NAME must be set to your app package name!
You can read more at: https://developer.android.com/training/camera/photobasics.html

In my case it was because I had put the FileProvider in the wrong place in the AndroidManifest.xml file. It needed to be inside the <Application> tags.
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="com.myapp.app1" android:installLocation="auto">
<uses-sdk android:minSdkVersion="22" android:targetSdkVersion="27" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_SURFACE_FLINGER" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.BROADCAST_WAP_PUSH" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.RECEIVE_WAP_PUSH" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_SETTINGS" />
<uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />
<application android:label="app1.Android">
<meta-data android:name="com.google.android.maps.v2.API_KEY" android:value="AIzaSyCZF1O9_7-MXlxYfAEIxBQkr-dR8RiwiYE" />
<!-- ADD FILE PROVIDER HERE -->
<provider android:name="android.support.v4.content.FileProvider"
android:authorities="com.myapp.app1.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/file_paths"></meta-data>
</provider>
</application>
</manifest>

The problem I had was related to case-sensitivity.
On the line below
<provider android:name="android.support.v4.content.FileProvider"
android:authorities="com.myexample.myapp.fileProvider"
android:exported="false"
android:grantUriPermissions="true">
I erroneously had a single uppercase letter on the line android:authorities="com.myexample.myapp.fileProvider". It should be:
android:authorities="com.myexample.myapp.fileprovider" <!-- all lowercase -->
Or
android:authorities="${applicationId}.fileprovider"
The package name and value for android:authorities should be lowercase. Otherwise you will get the error:
System.ArgumentException: Unable to get file location. This most
likely means that the file provider information is not set in your
Android Manifest file. Please check documentation on how to set this
up in your project.

Make sure you only have one set of <application> tags
I was stuck on this error for literally weeks... Then I realised I had duplicate application tags.
defined once like this:
<application android:label="App2.Android"></application>
the second set of <application> tags had the correct configuration lower down, but were being ignored. Removing the empty tags solved the issue for me.

Marco's solution is almost right. For it to work in my project I had to change
android:authorities="YOUR_APP_PACKAGE_NAME.fileprovider"
to
android:authorities="${applicationId}.fileprovider"
in the AndroidManifest.xml file.

Above answers resolved this issue for me. Here's what my AndroidManifest.xml looks like (using ${applicationId} for the authorities tag helps because sometimes you just don't know exactly how your app name is):
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
android:versionCode="1" android:versionName="1.0" package="com.companyname.app2">
<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="30" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<application android:label="App2.Android" android:theme="#style/MainTheme">
<provider android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/file_paths"></meta-data>
</provider>
</application>
</manifest>

<provider android:name="androidx.core.content.FileProvider"
android:authorities="APP_PACKAGE_NAME.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/file_paths"></meta-data>
</provider>
Xml must be in under xml folder

With the latest version, correct XML configuration is (without adding the package name to the path)
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-files-path name="my_images" path="Pictures" />
<external-files-path name="my_movies" path="Movies" />
</paths>
If you set path combining the package name like below
<external-path name="my_images" path="Android/data/YOUR_APP_PACKAGE_NAME/files/Pictures" />
It may give this type of error.

Android Support Libraries are now in the androidx.* package hierarchy instead of android.support.
So use following provider tag in you application's manifest.xml file.
<provider android:name="androidx.core.content.FileProvider"
android:authorities="YOUR_APP_PACKAGE_NAME.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/file_paths"></meta-data></provider>
It must be under application tag.

In addition to these things I had to do one more thing to get rid of this error. I had manually added the xml folder and file_paths.xml into the project folder. However, I had not yet added them to the project in the solution. Once I right clicked on the Resources folder and added New Folder (xml) and Existing Item (file_paths.xml) the error went away.

Categories

Resources