OnResume 相机重新初始化黑屏

我有个问题。初始化相机进行预览并使另一个应用程序进入焦点后，然后返回我的应用程序：预览显示为黑色。如果我继续拍照，它会拍摄我通常将相机指向的位置的照片。

我在 OnResume() 覆盖上做错了什么吗？相关代码如下：

public void ReleaseCamera()
    {
        if (myCamera != null)
        {
            myCamera.Release();
            myCamera = null;
        }
    }

protected override void OnPause()
    {
        base.OnPause();

        if (myButtonState == ButtonState.CameraActive)
            ReleaseCamera();
    }

protected override void OnResume()
    {
        base.OnResume();

        if (myButtonState == ButtonState.CameraActive)
            InitializeCamera();
    }

private void InitializeCamera()
    {
        SurfaceView mySurfaceView = FindViewById<SurfaceView>(Resource.Id.surfaceView1);

        myCamera = Android.Hardware.Camera.Open(cameraNumber);
        Android.Hardware.Camera.Parameters p = myCamera.GetParameters();

        myCamera.SetDisplayOrientation(90); // Portrait
        myCamera.SetPreviewDisplay(mySurfaceView.Holder);
        myCamera.StartPreview();
    }

感谢您的帮助。 :)

onResume() http://developer.android.com/reference/android/app/Activity.html#onResume%28%29被叫得太早了。此阶段您还没有准备好表面支架。你可以尝试介绍一下onPostResume() http://developer.android.com/reference/android/app/Activity.html#onPostResume%28%29您的 Activity 中的处理程序，和/或处理SurfaceHolder.Callback.surfaceChanged() http://developer.android.com/reference/android/view/SurfaceHolder.Callback.html#surfaceChanged%28android.view.SurfaceHolder,%20int,%20int,%20int%29 event.