android - WindowManager 在 Android OS 6 特定设备上崩溃

Question

我正在使用一项服务来创建 facebook Messenger 风格的 chatHead。我的代码适用于 Android OS 到 6(Marshmallow)的设备。但在 M 设备上，代码因 windowManager.addView() 运行时异常而崩溃

代码如下:

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);

我收到的崩溃是

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

Answer 1

看了http://qiita.com/chibatching/items/add5e50921c2da5ee1c7之后并尝试自己

检查您的代码是否在 Marshmallow 及更高版本上运行。如果是，请检查应用程序是否有权绘制叠加层。如果不引导用户进行设置。在 onActivityResult 中，如果用户已授予权限，您可以调用 displayOverdraw。如果用户之前已授予权限，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:为了测试，我在 Activity 中尝试了这个。在服务中你不能调用 startActivityForResult