如何使用材料设计中的显示效果在Android上显示对话框？

Question

我有Activity一个FloatingActionButton.当我按下FAB时,AlertDialog会显示一个.我想使用类似揭示从效果或弯曲运动,以动画它的外观Android的Material Design.该文档仅提供了更改现有视图可见性的示例.

我怎样才能实现这一目标AlertDialog？

Answer 1

如果您有自定义视图（在 XML 中定义），您可以尝试以下操作：

AlertDialog a = new AlertDialog.Builder(this)...blablabla;
View v = a.findViewById(R.layout.example);

// get the center for the clipping circle
int cx = (v.getLeft() + v.getRight()) / 2;
int cy = (v.getTop() + v.getBottom()) / 2;

// get the final radius for the clipping circle
int finalRadius = Math.max(v.getWidth(), v.getHeight());

// create the animator for this view (the start radius is zero)
Animator anim = ViewAnimationUtils.createCircularReveal(v, cx, cy, 0, finalRadius);

// make the view visible and start the animation
v.setVisibility(View.VISIBLE);
anim.start();

要使用反向动画隐藏它：

View v = <yourAlertDialog>.findViewById(R.layout.example);

// get the center for the clipping circle
int cx = (v.getLeft() + v.getRight()) / 2;
int cy = (v.getTop() + v.getBottom()) / 2;

// get the initial radius for the clipping circle
int initialRadius = v.getWidth();

// create the animation (the final radius is zero)
Animator anim = ViewAnimationUtils.createCircularReveal(v, cx, cy, initialRadius, 0);

// make the view invisible when the animation is done
anim.addListener(new AnimatorListenerAdapter() {
    @Override
    public void onAnimationEnd(Animator animation) {
        super.onAnimationEnd(animation);
        v.setVisibility(View.INVISIBLE);
    }
});

// start the animation
anim.start();