Android 当我调用可见性时动画不工作

Question

设置visibility为Invisible后动画不起作用，我试过clear animation也不行。我有一个按钮，当我单击该按钮时，它会打开一个带有动画的线性布局，当我按下后退按钮时，我再次将线性布局可见性设置为不可见我单击按钮线性布局出现，但没有动画请帮助我。

l1 = (LinearLayout) findViewById(R.id.lnrlgn);
  l2 = (LinearLayout) findViewById(R.id.lnrlgn1);
  l2.setVisibility(View.INVISIBLE);
  Animation  uptodown = AnimationUtils.loadAnimation(this,R.anim.uptodown);
  viewcrrd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                l2.setAnimation(downtoup);

                l2.clearanimation(); // is it right ?

                l2.setVisibility(View.VISIBLE);

            }
        });
 public void onBackPressed() {
//        super.onBackPressed();

        if (back_pressed + TIME_DELAY > System.currentTimeMillis()) {
//            super.onBackPressed();
            Exitdlg alert = new Exitdlg();
            alert.showDialog(LoginActivity.this, "Are You Sure ");
            l2.clearAnimation();

        } else {

            l2.clearAnimation();


            l2.setVisibility(View.INVISIBLE);



        }
        back_pressed = System.currentTimeMillis();


    }

Answer 1

使用startAnimation代替setAnimation

 viewcrrd.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            l2.setVisibility(View.VISIBLE);

             l2.clearanimation(); 

            l2.startAnimation(downtoup);

        }
    });

Android 当我调用可见性时动画不工作

Android Animation not work when i call visibility

animation

android

visibility