Android设置屏幕亮度及Alpha值

package com.xpf.someexamples;import android.app.Activity;import android.content.Context;import android.view.Window;import android.view.WindowManager;/** * Created by xpf on 2017/5/14 :) * GitHub:xinpengfei520 * Function:设置屏幕亮度及Alpha值 */public class BrightnessManager {    /**     * 设置当前activity的屏幕亮度     *     * @param paramFloat 0-1.0f     * @param context    需要调整亮度的activity context     */    public static void setBrightness(float paramFloat, Context context) {        Activity activity = (Activity) context;        Window localWindow = activity.getWindow();        WindowManager.LayoutParams params = localWindow.getAttributes();        params.screenBrightness = paramFloat;        localWindow.setAttributes(params);    }    /**     * 获取当前activity的屏幕亮度     *     * @param context 当前activity context对象     * @return 亮度值范围为0-0.1f，如果为-1.0，则亮度与全局同步     */    public static float getBrightness(Context context) {        Activity activity = (Activity) context;        Window localWindow = activity.getWindow();        WindowManager.LayoutParams params = localWindow.getAttributes();        return params.screenBrightness;    }    /**     * 设置手机屏幕透明度0-1.0f     */    public static void setAlpha(float light, Context context) {        Activity activity = (Activity) context;        Window window = activity.getWindow();        WindowManager.LayoutParams lp = window.getAttributes();        lp.alpha = light;        window.setAttributes(lp);    }    /**     * 设置手机屏幕透明度变暗     */    public static void lightoff(Context context) {        Activity activity = (Activity) context;        Window window = activity.getWindow();        WindowManager.LayoutParams lp = window.getAttributes();        lp.alpha = 0.3f;        window.setAttributes(lp);    }    /**     * 设置手机屏幕透明度显示正常     */    public static void lighton(Context context) {        Activity activity = (Activity) context;        Window window = activity.getWindow();        WindowManager.LayoutParams lp = window.getAttributes();        lp.alpha = 1.0f;        window.setAttributes(lp);    }}

使用此工具类可以设置popupwindow弹出时的屏幕变暗效果，见下图：

Thanks all.

2017.5.14