Need solution my bug with context android
<p>I have application which is connected with webservice. 
When I start application I call class:</p>

<pre><code>public class CaApplication extends Application {

    @Override
    public void onCreate() {
        // TODO Auto-generated method stub
        super.onCreate();
        DataRetrieve dr ;
        ProgressDialog progressBar;

            progressBar = new ProgressDialog(this);

            //progress bar orientation
            progressBar.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);

            // Text that will appear on the progress bar dialog
            progressBar.setMessage("Loading...");

        //set whether the progress bar is cancelable or not
            progressBar.setCancelable(false);
            progressBar.show();
         dr = new DataRetrieve();
    }
}
</code></pre>

<p>I get Error:</p>

<pre><code>11-25 15:39:36.698: E/AndroidRuntime(30429): Caused by: 11-25 15:39:36.698: E/AndroidRuntime(30429): java.lang.RuntimeException: Unable to create application com.example.storeclientdropdown.CambiumApplication: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.app.ActivityThread.handleBindApplication(ActivityThread.java:3974)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.app.ActivityThread.access$1300(ActivityThread.java:127)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.os.Handler.dispatchMessage(Handler.java:99)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.os.Looper.loop(Looper.java:137)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.app.ActivityThread.main(ActivityThread.java:4441)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at java.lang.reflect.Method.invokeNative(Native Method)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at java.lang.reflect.Method.invoke(Method.java:511)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at dalvik.system.NativeStart.main(Native Method)
11-25 15:39:36.698: E/AndroidRuntime(30429): Caused by: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.view.ViewRootImpl.setView(ViewRootImpl.java:517)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:301)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:215)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.view.WindowManagerImpl$CompatModeWrapper.addView(WindowManagerImpl.java:140)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.app.Dialog.show(Dialog.java:278)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at com.example.storeclientdropdown.CambiumApplication.onCreate(CambiumApplication.java:35)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:969)
11-25 15:39:36.698: E/AndroidRuntime(30429):    at android.app.ActivityThread.handleBindApplication(ActivityThread.java:3971)
11-25 15:39:36.698: E/AndroidRuntime(30429):    ... 10 more
</code></pre>

<p>In DataRetrive I get all data from webservice and after that I call MainActivity.
What is wrong and how I can fix this bug. I try: <code>progressBar = new ProgressDialog(this);</code>, <code>progressBar = new ProgressDialog(getApplicationContext());</code>, <code>progressBar = new ProgressDialog(getBaseContext);</code> but no result.</p>
