View的展开代码（含动画）

finalLinearLayout.LayoutParams expandParams = (LinearLayout.LayoutParams)expandArea.getLayoutParams();

Interpolator mExpandInterpolator =newDecelerateInterpolator(EXPAND_DECELERATION);

ValueAnimator animator = ValueAnimator.ofFloat(0f,1f)

.setDuration(EXPAND_DURATION);

animator.setInterpolator(mExpandInterpolator);

animator.addUpdateListener(newValueAnimator.AnimatorUpdateListener() {

@Override

public voidonAnimationUpdate(ValueAnimator animator) {

Float value = (Float) animator.getAnimatedValue();

// For each value from 0 to 1, animate the various parts of the layout.

expandParams.height= (int) (value *EXPAND_HEIGHT);

expandArea.requestLayout();

}

});

// Set everything to their final values when the animation's done.

animator.addListener(newAnimator.AnimatorListener() {

@Override

public voidonAnimationEnd(Animator animation) {

// Set it back to wrap content since we'd explicitly set the height.

isExpand=true;

}

@Override

public voidonAnimationCancel(Animator animation) {

}

@Override

public voidonAnimationRepeat(Animator animation) { }

@Override

public voidonAnimationStart(Animator animation) { }

});

animator.start();