android – Alpha动画无法正常工作

非常简单：我在屏幕上添加一个动态按钮,我尝试在添加后将其淡出,但动画永远不会播放.我稍后在屏幕上渲染时尝试添加它,但仍然没有.以下是代码：

btn = new ImageButton(context);
btn.setBackgroundColor(0xFFFF0000);

params = new WindowManager.LayoutParams(
    width,height,
    WindowManager.LayoutParams.TYPE_SYSTEM_ALERT | 
    WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
    WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE |
    WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH |
    WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS,
    PixelFormat.TRANSLUCENT);
params.gravity = Gravity.TOP | Gravity.LEFT;

windowManager.addView(btn, params);

btn.startAnimation(new AlphaAnimation(1,0));

有任何想法吗？

解决方法:

试试这个：

btn.setAlpha(0f);
btn.animate().alpha(1).setDuration(1000);

标签：android,animation,imagebutton
来源： https://codeday.me/bug/20190831/1776211.html