Question

In Android there seems to be 3 common ways of handling button clicks, how much difference is there between the methods? And are any of them ‘better’ in some way?

The three methods I keep seeing are:

Anonymous class

Find the button by it’s ID, then pass a new anonymous class to setOnClickListener, e.g. in onCreate

findViewById(R.id.myButton).setOnClickListener(new OnClickListener() {
    public void onClick(View v) {
        // .. Whatever
    }
});

Implement OnClickListener

Implement OnClickListener and pass this to setOnClickListener, then use a switch statment based on the button ID, e.g. in onCreate

findViewById(R.id.myButton).setOnClickListener(this);

and implement onClick like

public void onClick(View v) {
    switch(v.getId()) {
        case R.id.myButton:
            // ... whatever ...
            break;
    }
}

Use onClick XML atribute

In the XML layout for your activity, instead of giving your button an ID, use onClick like this:

<Button 
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:onClick="buttonClicked" 
    android:text="Button" />

Then have a buttonClicked method in your Acitiviy like this:

public void buttonClicked(View v) {
    // ... whatever ...
}

At the moment I tend to use the XML attribute, but that’s just because it involves the least amount of code. When should I use the other methods?

Answer 1

The first two are the classic approaches. Which one you prefer is more of a general Java question than an Android question.
The third one was added later to make things easier.

Setting up a click listener on a button is very common task, but it
requires quite a bit of boilerplate code. One way to reduce the amount
of boilerplate is to share a single click listener between several
buttons. While this technique reduces the number of classes, it still
requires a fair amount of code and it still requires giving each
button an id in your XML layout file. With Android 1.6, none of this
is necessary. All you have to do is declare a public method in your
Activity to handle the click (the method must have one View argument)

Source