1.获取当前当前运行在前台的app的包名

  public static String getCurrentPkgName(Context context) {
        // 5x系统以后利用反射获取当前栈顶activity的包名。
        ActivityManager.RunningAppProcessInfo currentinfo = null;
        Field field = null;
        int startTaskToFront = 2;
        String pkgName = null;
        try {
            //通过反射获取进程状态字段
            field = ActivityManager.RunningAppProcessInfo.class.getDeclaredField("processState");
        } catch (Exception e) {
            e.printStackTrace();
        }
        ActivityManager am = (ActivityManager) context.getSystemService(ACTIVITY_SERVICE);
        List appList = am.getRunningAppProcesses();
        ActivityManager.RunningAppProcessInfo app;
        for (int i = 0; i < appList.size(); i++) {
            //ActivityManager.RunningAppProcessInfoapp:appList
            app = (ActivityManager.RunningAppProcessInfo) appList.get(i);
            //表示前台运行进程•
            if (app.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
                Integer state = null;
                try {
                    //反射调用字段值的方法,获取该进程的状态。
                    state = field.getInt(app);
                } catch (Exception e) {
                    e.printStackTrace();
                }
                //根据这个判断条件从前台获取当初切换的对象
                if (state != null && state == startTaskToFront) {
                    currentinfo = app;
                    break;
                }
            }
        }

        if (currentinfo != null) {
            pkgName = currentinfo.processName;
        }

        Log.e("lmj", "pkgname = " + pkgName);

        return pkgName;
    }

2.通过获取的包名杀死当前运行在前台的app

  public static void killApp(String packageName) {
        //获取应用程序管理器
        ActivityManager manager = (ActivityManager) ContextUtil.getContext().getSystemService(ACTIVITY_SERVICE);
        //manager.killBackgroundProcesses(packageName);
        manager.forceStopPackage(packageName);
    }