Is There any method by which I can call a method every time a new activity starts in an app?

Question

I am using an external jar for some functionality in my Android project but I need to call the initialize function on every onStart() function. Is there a method, I can skip this step and it will automatically gets called every time a new activity start.

I am aware that some code injection techniques are available. Can some one please explain it in details or provide some source for it.

Answer 1

你可以试试这个：

protected void onCreate(Bundle savedInstanceState);

Answer 2

Make a class extend Activity class and put call to your library method in it's protected void onCreate(Bundle savedInstanceState); method.

Now make all your custom activities in which you need to call your library method on create extend above class rather than extending Activity directly.

In short use Inheritance!

Answer 3

onCreate(Bundle bundle) is the answer. You may also need to look for the onResume and onStart methods.

Answer 4

You might acheive this by creating a custom Activity class and overiding its onStart method. Then extend all your Activities from this custom Activity.

    public class CustomActivity extends Activity{
       @Override
       protected void onStart() {
            // TODO Auto-generated method stub
            super.onStart();
           // call your method.
       }

    }

and then extend your activities from this custom Activity.

Answer 5

You do this as follows without modifying each activity.

Create a class which extends android.app.Application like

public class YourApplication extends Application {

    @Override
    public void onCreate() {
         // do whatever start-up processes you want to perform in this method
    }
}

Next, modify the application manifest files as follows

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="application.package"
    android:versionCode="1"
    android:versionName="1.0" >

    <application
    ...
        android:name="application.package.YourApplication"
    ... >
    </application>
</manifest>

Hope this helps.