while deny the camera permission in android it wont ask again - xamarin

Question

first time application asking permission for the camera, if we deny the permission it won't ask again if we allow its working fine ??
var scanPage = new ZXingScannerPage();
var cameraStatus = await CrossPermissions.Current.CheckPermissionStatusAsync(Permission.Camera);
if (cameraStatus != PermissionStatus.Granted)
{
var results = await CrossPermissions.Current.RequestPermissionsAsync(new[] { Permission.Camera });
cameraStatus = results[Permission.Camera];
if (cameraStatus == PermissionStatus.Granted)
{
// Navigate to our scanner page
await Navigation.PushAsync(scanPage);
scanPage.OnScanResult += (result) =>
{
Device.BeginInvokeOnMainThread(async () =>
{
await Navigation.PopAsync();
txtbarcode.Text = result.Text;
});
};
}
else if (cameraStatus == PermissionStatus.Unknown)
{
await Navigation.PushAsync(scanPage);
scanPage.OnScanResult += (result) =>
{
Device.BeginInvokeOnMainThread(async () =>
{
await Navigation.PopAsync();
txtbarcode.Text = result.Text;
});
};
}
If we deny the camera permission, again its asks while opening camera until we allow the permission.

Answer 1

I wrote a demo about this.
https://github.com/851265601/CheckPermissionDemo
This a GIF of this demo.
Did you check the permission every time when you use the camera function? In this demo, when i click the button ,it will check the permission, then give the result to users, if not give the permission, it will still ask the persmission like the following code.
async void ButtonPermission_OnClicked(object sender, EventArgs e)
{
if (busy)
return;
busy = true;
((Button)sender).IsEnabled = false;
var status = await CrossPermissions.Current.CheckPermissionStatusAsync(Permission.Camera);
await DisplayAlert("Pre - Results", status.ToString(), "OK");
if (status != PermissionStatus.Granted)
{
status = await Utils.CheckPermissions(Permission.Camera);
await DisplayAlert("Results", status.ToString(), "OK");
}
busy = false;
((Button)sender).IsEnabled = true;
}
}
When DisplayAlert was appear, it are used MainApplication for different life cycle
namespace CheckPermissionDemo.Droid
{
//You can specify additional application information in this attribute
[Application]
public class MainApplication : Application, Application.IActivityLifecycleCallbacks
{
public MainApplication(IntPtr handle, JniHandleOwnership transer)
: base(handle, transer)
{
}
public override void OnCreate()
{
base.OnCreate();
RegisterActivityLifecycleCallbacks(this);
//A great place to initialize Xamarin.Insights and Dependency Services!
}
public override void OnTerminate()
{
base.OnTerminate();
UnregisterActivityLifecycleCallbacks(this);
}
public void OnActivityCreated(Activity activity, Bundle savedInstanceState)
{
CrossCurrentActivity.Current.Activity = activity;
}
public void OnActivityDestroyed(Activity activity)
{
}
public void OnActivityPaused(Activity activity)
{
}
public void OnActivityResumed(Activity activity)
{
CrossCurrentActivity.Current.Activity = activity;
}
public void OnActivitySaveInstanceState(Activity activity, Bundle outState)
{
}
public void OnActivityStarted(Activity activity)
{
CrossCurrentActivity.Current.Activity = activity;
}
public void OnActivityStopped(Activity activity)
{
}
}
}