MiniProgramError Cannot read property 'getContext' of null TypeError: Cannot read property 'getContext' of null at getContext (pages/pages/home/detail/canvas/canvas.ts:30:28) SystemError (appServiceSDKScriptError) NativeGlobal.SkiaCanvasView is not a constructor TypeError: NativeGlobal.SkiaCanvasView is not a constructor 这是报错，不知道是什么原因引起的，希望可以解决