我有一个简单的表格，

 [Serializable]
class CreateNewLeadForm
{
    public string FirstName;
    public string LastName;
    public static IForm<CreateNewLeadForm> BuildForm()
    {

        return new FormBuilder<CreateNewLeadForm>()
            .Message("Lets create a New Lead")
            .Field(nameof(FirstName))
            .Field(nameof(LastName))
            .Build();

    }
};

还有一个简单的对话框

public class GreetDialog : IDialog<object>
{        
    public async Task StartAsync(IDialogContext context)
    {

        context.Wait(MessageReceivedAsync);
    }
    public   async Task MessageReceivedAsync(IDialogContext context, IAwaitable<Message> argument)
    {
       context.Wait(MessageReceivedAsync);
    }  
}

如何从主对话框本身调用“启动FormDialog”？总的来说，我们如何在对话框中创建新对话框？