ScreenUtils.java 文件源码

/**
 * 调整窗口的透明度  1.0f,0.5f 变暗
 *
 * @param from    from>=0&&from<=1.0f
 * @param to      to>=0&&to<=1.0f
 * @param context 当前的activity
 */
public static void dimBackground(final float from, final float to, Activity context) {
    final Window window = context.getWindow();
    ValueAnimator valueAnimator = ValueAnimator.ofFloat(from, to);
    valueAnimator.setDuration(500);
    valueAnimator.addUpdateListener(
            new ValueAnimator.AnimatorUpdateListener() {
                @Override
                public void onAnimationUpdate(ValueAnimator animation) {
                    WindowManager.LayoutParams params = window.getAttributes();
                    params.alpha = (Float) animation.getAnimatedValue();
                    window.setAttributes(params);
                }
            });
    valueAnimator.start();
}