播放本地视频，以及第一帧渲染

// 视频播放器
[SerializeField] private UnityEngine.Video.VideoPlayer videoPlayer;
// 视频textture容器
[SerializeField] private UnityEngine.UI.RawImage rawImage;

第一帧渲染
IEnumerator ShowVideoFirstFrame()
    {
        videoPlayer.time = 0;
        videoPlayer.Prepare();
        WaitForSeconds waitForSeconds = new WaitForSeconds(1);
        while (!videoPlayer.isPrepared)
        {
            yield return waitForSeconds;
            break;
        }
        videoPlayer.Play();
        rawImage.texture = videoPlayer.texture;
        videoPlayer.Pause();
    }

//视频播放
void PlayVideo()
    {
        videoPlayer.Play();
        rawImage.texture = videoPlayer.texture;
        // 检测当前动画是否播放完成
        // videoPlayer.loopPointReached += CheckOver;

    }

//获取商场路径
public void OnUploadClick(UContent content, FPointerEventData data)
    {
        filePath = "";
        filePath = EditorUtility.OpenFilePanel("upload file", "", fileExtension);  // 自己选择文件，获取到Assets路径
        print(filePath);
        if (filePath != "")
        {
            videoPlayer.url = filePath;
            // 预览视频第一帧
            PreviewVideo();
        }else
        {
            
        }

    }