Android 点击按钮动画改变控件的高度并且不占位置

最终效果

activity_main 布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_height="match_parent">
    <Button
        android:id="@+id/btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="点击"/>
            <LinearLayout
                android:id="@+id/ll_view"
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="0"
                android:orientation="vertical"
                android:background="#ff00"/>
</LinearLayout>

Java代码

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }
    private void initView() {

        //设置高度
        height = 500;
        show = true;
        btn = findViewById(R.id.btn);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if(show){
                    //显示view，高度从0变到height值
                    va = ValueAnimator.ofInt(0,height);
                    show = false;
                }else{
                    //隐藏view，高度从height变为0
                    va = ValueAnimator.ofInt(height,0);

                    show = true;
                }
                va.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                    @Override
                    public void onAnimationUpdate(ValueAnimator valueAnimator) {
                        //获取当前的height值
                        int h =(Integer)valueAnimator.getAnimatedValue();
                        //动态更新view的高度
                        ll_view.getLayoutParams().height = h;
                        ll_view.requestLayout();
        
                        Log.d("ss", h+"");
                    }
                });
                va.setDuration(1000);
                //开始动画
                va.start();
            }
        });
        ll_view = findViewById(R.id.ll_view);
    }
}