I am facing problem is when i press button back , my app is crash. My ScanActivity:
public class ScanActivity extends AppCompatActivity implements BarcodeReader.BarcodeReaderListener {
BarcodeReader barcodeReader;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_scan);
barcodeReader = (BarcodeReader) getSupportFragmentManager().findFragmentById(R.id.barcode_scanner);
}
My function to scaning my Qrcode.
@Override
public void onScanned(Barcode barcode) {
Intent intent = new Intent(ScanActivity.this,TicketActivity.class);
intent.putExtra("code",barcode.displayValue.toString() );
startActivity(intent);
}
Scaning multiple barcodes
@Override
public void onScannedMultiple(List<Barcode> barcodes) {
}
@Override
public void onBitmapScanned(SparseArray<Barcode> sparseArray) {
}
Return error.
@Override
public void onScanError(String errorMessage) {
Toast.makeText(ScanActivity.this,"Error " +errorMessage ,Toast.LENGTH_LONG).show();
}
@Override
public void onCameraPermissionDenied() {
finish();
}
}
And Logcat i read it but i cannot found the problem.
04-06 12:17:25.871 30393-30393/com.example.mobilevision E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.mobilevision,
java.lang.RuntimeException: Unable to destroy activity {com.example.mobilevision/com.example.mobilevision.ScanActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Thread$State java.lang.Thread.getState()' on a null object reference
at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3831)
at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3849)
at android.app.ActivityThread.-wrap5(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1398)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Thread$State java.lang.Thread.getState()' on a null object reference
Should i need add function onDestroy ?
