安卓操作系统6专用设备上的WindowManager崩溃

Question

我正在使用一个服务来创建一个facebook信使风格的chatHead。我的代码在使用android的设备上运行良好，直到6(Marshmallow)。但是在M设备上，代码在windowManager.addView()上运行时异常崩溃。

守则如下：

windowManager = (WindowManager) ctx.getSystemService(WINDOW_SERVICE);
callHead = new ImageView(this);
callHead.setImageResource(R.drawable.ic_flow_flat);
params = new WindowManager.LayoutParams(
            WindowManager.LayoutParams.WRAP_CONTENT,
            WindowManager.LayoutParams.WRAP_CONTENT,
            PixelFormat.TRANSLUCENT);

params.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
            | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR
            | WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM;     
params.gravity = Gravity.TOP | Gravity.LEFT;
params.x = 0;
params.y = 100;
params.height = 120; // given it a fixed height in case of large image
params.width = 120;
windowManager.addView(callHead, params);

我收到的撞击是

Caused by: android.view.WindowManager$InvalidDisplayException: Unable to add window android.view.ViewRootImpl$W@b40f577 -- the specified window type is not valid

Answer 1

在看了http://qiita.com/chibatching/items/add5e50921c2da5ee1c7之后自己试了一下

检查您的代码是否运行在Marshmallow和上面。如果是，请检查应用程序是否有绘制覆盖层的权限。如果没有，则将用户引导到设置。在onActivityResult中，如果用户已授予权限，则可以调用displayOverdraw。如果用户先前已授予权限，则无需再次显示设置屏幕。

 public void checkdrawPermission() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (!Settings.canDrawOverlays(this)) {
                Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION,
                        Uri.parse("package:" + getPackageName()));
                startActivityForResult(intent, REQUEST_CODE_ASK_PERMISSIONS);
            } else {
                 // display over lay from service
            }
        }else
        {
             // display over lay from service
        }
    }

onActivityResult回调

 @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == REQUEST_CODE_ASK_PERMISSIONS) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                if (Settings.canDrawOverlays(this)) {
                    // You have permission
                    // display over lay from service
                }
            }
        }
    }

服务中的绘制覆盖

public void displayOverdraw() {

    ImageView callHead = new ImageView(this);
    callHead.setImageResource(R.mipmap.ic_launcher);

    WindowManager.LayoutParams params = new WindowManager.LayoutParams(
            WindowManager.LayoutParams.WRAP_CONTENT,
            WindowManager.LayoutParams.WRAP_CONTENT,
            WindowManager.LayoutParams.TYPE_SYSTEM_ALERT,
            WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH,
            PixelFormat.TRANSLUCENT);
    params.gravity = Gravity.BOTTOM | Gravity.RIGHT;
    WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);
    wm.addView(callHead, params);
}

注意:为了进行测试，我在活动中尝试了这一点。在服务中，不能调用startActivityForResult