NullPointerException addToRequestQueue(com.android.volley.Request, java.lang.String)' on a null object reference

Question

I'm using AndroidHive register login and it's working fine in example project of this login-register.

But after many attempts trying it with CardViews and other widgets, this error appears on the LogCat:

java.lang.NullPointerException: Attempt to invoke virtual method 'void client.myproject.app.AppController.addToRequestQueue(com.android.volley.Request, java.lang.String)' on a null object reference
            at client.myproject.RegisterActivity.registerUser(RegisterActivity.java:185)
            at client.myproject.RegisterActivity.access$300(RegisterActivity.java:35)
            at client.myproject.RegisterActivity$1.onClick(RegisterActivity.java:81)
            at android.view.View.performClick(View.java:4780)
            at android.view.View$PerformClick.run(View.java:19866)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5254)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

While these codes works fine in a single app (just with register login).

I'm using Volley library.

Answer 1

In your AndroidManifest.xml add

<application android:name="YOURPACKAGENAME.AppController" 
             android:allowbackup="true" 
             android:icon="@drawable/ic_launcher" 
             android:label="@string/app_name"
             android:theme="@style/AppTheme">