Open Magnabatt opened 6 years ago
chiragjuneja
commented
6 years ago I am also facing the similar crash when I try to open the scan page. I noticed that it is happening once I upgraded to Xamarin.forms 2.5.0.* version.
[ERROR] FATAL UNHANDLED EXCEPTION: Java.Lang.NullPointerException: Attemptinvoke virtual method 'android.content.res.Resources android.content.Context.getResources()' oa null objecreference
aSystem.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] i
F0rc0sigan
commented
6 years ago I am getting the same issue
chiragjuneja
commented
6 years ago Any update on this? We can't move back to Xamarin.forms 2.4 and QR code scanning is not working for with Xamarin.forms 2.5.
knight1219
commented
6 years ago I have having the same issue: VS 15.7.3, Xamarin Forms 3.0.0.530983, ZXing 2.4.1
Has anyone solved this?
Magnabatt
commented
6 years ago Hi All,
Sorry for the delay. I have managed to get this working by updating my on click action to the below;
//Open QR scanner for code scanning
private async void BtnScanQR_Clicked(object sender, EventArgs e)
{
try
{
var options = new MobileBarcodeScanningOptions
{
AutoRotate = false,
UseFrontCameraIfAvailable = false,
TryHarder = true
};
var overlay = new ZXingDefaultOverlay
{
TopText = "Please scan QR code",
BottomText = "Align the QR code within the frame"
};
var QRScanner = new ZXingScannerPage(options,overlay);
await Navigation.PushModalAsync(QRScanner);
QRScanner.OnScanResult += (result) =>
{
// Stop scanning
QRScanner.IsScanning = false;
// Pop the page and show the result
Device.BeginInvokeOnMainThread(() =>
{
Navigation.PopModalAsync(true);
strAccessToken.Text = result.Text.ToUpper().Trim();
//DisplayAlert("Scanned Barcode", result.Text, "OK");
});
};
}
catch (Exception ex)
{
GlobalScript.SeptemberDebugMessages("ERROR", "BtnScanQR_Clicked", "Opening ZXing Failed: " + ex);
}
}
Hope this works for you. Also if you find any improvements in the above please share with me.
Packages: Xamarin.Forms 2.5.1.52743 ZXing.Net.Mobile.Forms 2.3.2
suyana
commented
6 years ago @knight1219
if you used mvvmcross 6 ?? add this code at MainActivity Xamarin.Forms.Forms.Init(this, bundle);
pablocity
commented
6 years ago @suyana That actually worked! I was facing this error for a while, so thank you very much :)
danylo-kachanov
commented
5 years ago @suyana thank you! it helps me too!
gcoleman0828
commented
5 years ago ZXing.Net.Mobile.Forms.Android.Platform.Init(); Did not work for me. the newest version to date (12/31/2018) v2.4.1 still crashes. MobileBarcodeScanner.Initialize(Application); works adding to MainActivity.cs
ZXing.Net.Mobile: 2.4.1 ZXing.Net.Mobile.Forms: 2.4.1 Xamarin.Form: 3.4.0.1008975 Xamarin.Android.xxx: 28.0.0
Maxallica
commented
5 years ago I got the same issue. Please can you fix this critical issue!
UNHANDLED EXCEPTION:
Java.Lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
at Java.Interop.JniEnvironment+InstanceMethods.CallNonvirtualVoidMethod (Java.Interop.JniObjectReference instance, Java.Interop.JniObjectReference type, Java.Interop.JniMethodInfo method, Java.Interop.JniArgumentValue args) [0x00089] in
ZXing.Net.Mobile: 2.4.1 ZXing.Net.Mobile.Forms: 2.4.1 Xamarin.Forms: 3.5.0.129452 Xamarin.Android.Support.Annotations: 28.0.0.1 Xamarin.Android.Support.Compat: 28.0.0.1 Xamarin.Android.Support.Core.UI: 28.0.0.1 Xamarin.Android.Support.Design: 28.0.0.1 Xamarin.Android.Support.Fragment: 28.0.0.1 Xamarin.Android.Support.Media.Compat: 28.0.0.1 Xamarin.Android.Support.v4: 28.0.0.1 Xamarin.Android.Support.v7.AppCompat: 28.0.0.1 Xamarin.Android.Support.v7.CardView: 28.0.0.1 Xamarin.Android.Support.v7.MediaRouter: 28.0.0.1 Xamarin.Android.Support.v7.RecyclerView: 28.0.0.1
jramoseguinoa
commented
5 years ago Using @Maxallica commit I was able to fix this issue. I created a ViewRenderer (using the code that is referenced in his fork) in my android project that replaced the one in the library and now the issue is gone. Thanks for the fix @Maxallica !
bingxueyinlian
commented
4 years ago @suyana thank you! it helps me too!
Hi All, I feel this might be a double up but i have not been able to find a solution for the below error. Please let me know if a solution has been found?
I have recently updated VS to 15.6.7 and subsequently updated to Xamrin.Forms 2.5.1.444934 with Zxing.Net.Mobile 2.4.1 using .NETStandard 2.0. Since doing this I now get a null reference error each time I call the script.
Also I have only seen the error on Android (testing iOS tonight)
Here is the error:
In my MainActivity.cs I call the following after my Forms.Int:
//QR code readerglobal::ZXing.Net.Mobile.Forms.Android.Platform.Init();And this is the script with in my click event on the MainPage.cs:
//Open QR scanner for code scanningprivate async void BtnScanQR_Clicked(object sender, EventArgs e){try{var scanner = new MobileBarcodeScanner();var result = await scanner.Scan();strAccessToken.Text = result.Text.Trim();}catch (Exception ex){GlobalScript.DebugMessages("ERROR", "BtnScanQR_Clicked", "Opening ZXing Failed: " + ex);}}Even rolling back to my original versions of each package I'm now still having the same error.
Any assistance would be appretiated