startLocalPreview method Null safety
- bool frontCamera,
- dynamic viewId
Enable the preview image of local video
When the first camera video frame starts to be rendered, you will receive the onFirstVideoFrame(null) callback in TRTCCloudListener.
Parameters:
frontCamera true: front camera; false: rear camera.
viewId   viewId generated by TRTCCloudVideoView
Implementation
Future<void> startLocalPreview(
    bool frontCamera, // true: front camera; false: rear camera.
    viewId) {
  return TRTCCloudVideoViewController(viewId).startLocalPreview(frontCamera);
}