动画RelativeLayout边距更改

Question

代码：

RelativLayout.LayoutParams params = (RelativLayout.LayoutParams) view1.getLayoutParams();
params.setMargins(50, 0, 0, 0);
view1.setLayoutParams(params);

上面的代码工作正常，但我想为它设置动画。

Answer 1

你可以像这样使用ValueAnimator：

ValueAnimator varl = ValueAnimator.ofInt(50);
varl.setDuration(4000);
varl.addUpdateListener(new AnimatorUpdateListener() {

    @Override
    public void onAnimationUpdate(ValueAnimator animation) {
        RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) view1.getLayoutParams();
        lp.setMargins((Integer) animation.getAnimatedValue(), 0, 0, 0);
        view1.setLayoutParams(lp);      
    }
});
varl.start();

ValueAnimator可从Honeycomb获得，但您有NineOldAndroids端口。

Answer 2

或者更好的是，使用动画：

Animation animation = new Animation() {
    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        LayoutParams params = view1.getLayoutParams();
        params.leftMargin = (int)(50 * interpolatedTime);
        view1.setLayoutParams(params);
    }
};
animation.setDuration(300);
animation.setInterpolator(new OvershootInterpolator());
view1.startAnimation(animation);

或者更好的是，使用助手library：

ViewPropertyObjectAnimator.animate(view1).leftMargin(50).setDuration(300).start();