自定义操作示例返回空引用异常。

Question

我尝试为multiply实现自定义动作示例(乘)，如这里所示。我执行了所有步骤并复制了代码，但是当我试图在bot上执行操作时，我得到了一个具有以下堆栈跟踪的System.NullReferenceException：

   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ReplaceDialog.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginActionAsync(DialogContext dc, Int32 offset, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.OnNextActionAsync(DialogContext dc, Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.ResumeDialogAsync(DialogContext dc, DialogReason reason, Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.EndDialogAsync(Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.SetProperty.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginActionAsync(DialogContext dc, Int32 offset, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.OnNextActionAsync(DialogContext dc, Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.ResumeDialogAsync(DialogContext dc, DialogReason reason, Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.EndDialogAsync(Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.SendActivity.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginActionAsync(DialogContext dc, Int32 offset, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.AdaptiveDialog.ContinueActionsAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.AdaptiveDialog.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.ReplaceDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ReplaceDialog.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginActionAsync(DialogContext dc, Int32 offset, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.OnNextActionAsync(DialogContext dc, Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.ResumeDialogAsync(DialogContext dc, DialogReason reason, Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.EndDialogAsync(Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.SetProperty.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginActionAsync(DialogContext dc, Int32 offset, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.OnNextActionAsync(DialogContext dc, Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.ResumeDialogAsync(DialogContext dc, DialogReason reason, Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.EndDialogAsync(Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.SendActivity.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginActionAsync(DialogContext dc, Int32 offset, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.AdaptiveDialog.ContinueActionsAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.AdaptiveDialog.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.ReplaceDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ReplaceDialog.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginActionAsync(DialogContext dc, Int32 offset, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.OnNextActionAsync(DialogContext dc, Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.ResumeDialogAsync(DialogContext dc, DialogReason reason, Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.EndDialogAsync(Object result, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.SetProperty.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginActionAsync(DialogContext dc, Int32 offset, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.ReplaceDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.IfCondition.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginActionAsync(DialogContext dc, Int32 offset, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.Actions.ActionScope.BeginDialogAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.BeginDialogAsync(String dialogId, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.AdaptiveDialog.ContinueActionsAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.AdaptiveDialog.ContinueDialogAsync(DialogContext dc, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.ContinueDialogAsync(CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.AdaptiveDialog.ContinueActionsAsync(DialogContext dc, Object options, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.Adaptive.AdaptiveDialog.ContinueDialogAsync(DialogContext dc, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogContext.ContinueDialogAsync(CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogExtensions.InnerRunAsync(ITurnContext turnContext, String dialogId, DialogContext dialogContext, CancellationToken cancellationToken)
   at Microsoft.Bot.Builder.Dialogs.DialogExtensions.InternalRunAsync(ITurnContext turnContext, String dialogId, DialogContext dialogContext, DialogStateManagerConfiguration stateConfiguration, CancellationToken cancellationToken)

有人知道这里出了什么问题吗？据我所知，我尽可能接近这个教程。

Answer 1

检查是否忘记向appsettings.json添加组件

"components": [
  {
    "name": "YourCustomActionName"
  }
]

Answer 2

请按照以下步骤解决此错误System.NullReferenceException

将下列附加包添加到项目文件

<PackageReference Include="Microsoft.Bot.Builder.Dialogs.Adaptive" Version="4.9.1"/>

<PackageReference Include="Microsoft.Bot.Builder.Dialogs.Declarative" Version="4.9.1"/>

更新DefaultActivityHandler

声明两个新的局部变量

protected readonly DialogManager _dialogManager;
protected readonly ResourceExplorer _resourceExplorer;

更新构造函数以包括以下行

_resourceExplorer = serviceProvider.GetService<ResourceExplorer>();
_dialogManager = new DialogManager(dialog);
_dialogManager.UseResourceExplorer(_resourceExplorer);
_dialogManager.UseLanguageGeneration();

更新OnTurnAsync处理程序以使用_dialogManager代替_dialog

await _dialogManager.OnTurnAsync(turnContext, cancellationToken: cancellationToken);

参考：

https://microsoft.github.io/botframeworksolutions/skills/handbook/experimental-add-composer/

https://www.youtube.com/watch?v=QZJRtyYP0hY

https://github.com/rvinothrajendran/BotTutorialSample