Activity to Activity Communication

Activity myActivity  = AssumeSomeActivityExists();
    Intent openA开发者_运维问答ctivity = new Intent();
    openActivity.setAction(Intent.ACTION_VIEW);
    openActivity.setClass(myActivity,B.class);
    myActivity.startActivity(openActivity);

When we do something like above how to make B instance know that it is been called and created by Activity myActivity?

Use extras with your Intent.

Smth like openActivity.putExtra("calledFromA", true)

Then in B:

protected void onCreate(Bundle savedInstanceState) { {
    super.onCreate(savedInstanceState);
    boolean isCalledFromA = getIntent().getBooleanExtra("calledFromA", false);
}