Android6.0以上绘制系统级悬浮窗异常 permission denied for window type 2002

官方介绍

Allows an app to create windows using the type TYPE_SYSTEM_ALERT, shown on top of all other apps. Very few apps should use this permission; these windows are intended for system-level interaction with the user.

Note: If the app targets API level 23 or higher, the app user must explicitly grant this permission to the app through a permission management screen. The app requests the user's approval by sending an intent with action ACTION_MANAGE_OVERLAY_PERMISSION. The app can check whether it has this authorization by calling Settings.canDrawOverlays().

Protection level: signature

Constant Value: "android.permission.SYSTEM_ALERT_WINDOW"

解决代码

//权限判断
        if (Build.VERSION.SDK_INT >= 23) {
            if(!Settings.canDrawOverlays(getApplicationContext())) {
                //启动Activity让用户授权
                Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
                startActivity(intent);
                return;
            } else {
                //执行6.0以上绘制代码
            }
        } else {
            //执行6.0以下绘制代码
        }