Android-在XML和Java代码中设置背景在不同状态的效果: <selector>/StateListDrawable

It's true that if you override the default state you also have to override the pressed and focused states. The reason is that the default android drawable is a selector, and so overriding it with a static drawable means that you lose the state information for pressed and focused states as you only have one drawable specified for it. It's super easy to implement a custom selector, though. Do something like this:

<selector
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/custombutton">

<item
android:state_focused="true"
android:drawable="@drawable/focused_button" />
<item
android:state_pressed="true"
android:drawable="@drawable/pressed_button" />
<item
android:state_pressed="false"
android:state_focused="false"
android:drawable="@drawable/normal_button" />
</selector>

Put this in your drawables directory, and load it like a normal drawable for the background of the ImageButton. The hardest part for me is designing the actual images.

Edit:

Just did some digging into the source of EditText, and this is how they set the background drawable:

public EditText(/*Context context, AttributeSet attrs, int defStyle*/) {
super(/*context, attrs, defStyle*/);

StateListDrawable mStateContainer = new StateListDrawable();

ShapeDrawable pressedDrawable = new ShapeDrawable(new RoundRectShape(10,10));
pressedDrawable.getPaint().setStyle(Paint.FILL);
pressedDrawable.getPaint().setColor(0xEDEFF1);

ShapeDrawable focusedDrawable = new ShapeDrawable(new RoundRectShape(10,10));
focusedDrawable.getPaint().setStyle(Paint.FILL);
focusedDrawable.getPaint().setColor(0x5A8AC1);

ShapeDrawable defaultDrawable = new ShapeDrawable(new RoundRectShape(10,10));
defaultDrawable.getPaint().setStyle(Paint.FILL);
defaultDrawable.getPaint().setColor(Color.GRAY);

// mStateContainer.addState(new int[] { android.R.attr.state_pressed }, pressedDrawable);
mStateContainer.addState(View.PRESSED_STATE_SET, pressedDrawable);
mStateContainer.addState(View.FOCUSED_STATE_SET, focusedDrawable);
mStateContainer.addState(StateSet.WILD_CARD, defaultDrawable);

this.setBackgroundDrawable(mStateContainer);
}

Via: http://stackoverflow.com/questions/3859144/how-to-modify-the-default-button-state-in-android-without-affecting-the-pressed