android activity class constructor working

Question

When considering the case with android activity, the first method to work is its onCreate method..right?

Suppose i want to pass 2 parameters to android

Answer 1

I can see one situation where you'd be unable to use the standard method of passing the parameters via the Intent: When you're creating an activity that will be launched by another app (say, the edit activity of a Tasker plugin) and, therefore, do not have control over the Intent that will launch your activity.

It's possible to create an Activity that accepts parameters in its constructor. The trick to using it, though, is not to use it directly, but to use a derived class with a default constructor that calls super() with the appropriate arguments, as such:

class BaseActivity extends Activity
{
    public BaseActivity(String param1, int param2)
    {
        // Do something with param1 and param2.
    }
    // Many more lines of awesomeness.
}

class DerivedActivity extends BaseActivity
{
    public DerivedActivity()
    {
        super("param1", 42);
    }
}

Naturally, if you need to generate the parameters to pass to BaseActivity(), you can simply replace the hard-coded values with function calls.