VB.Net 'Sub Main' 未找到

Question

好的，我星期一有一个 A 级计算考试，我一直在研究预发布的框架代码。

今天早上，当我尝试时，我收到了一条错误消息 'Sub Main' was not found。我将在下面粘贴的代码中显然有一个Sub Main()。

我尝试添加另一个sub main()，然后收到第二个错误，说Sub Main() has multiple definitions。

我真的需要整理一下，所以任何帮助都将不胜感激。

下面是 Sub Main() 本身的代码：

 Sub Main()
    Dim Choice As Char
    Dim Deck(52) As TCard
    Dim RecentScores(NoOfRecentScores) As TRecentScore
    Randomize()
    Do
        DisplayMenu()
        Choice = GetMenuChoice()
        Select Case Choice
            Case "1"
                LoadDeck(Deck)
                ShuffleDeck(Deck)
                PlayGame(Deck, RecentScores)
            Case "2"
                LoadDeck(Deck)
                PlayGame(Deck, RecentScores)
            Case "3"
                DisplayRecentScores(RecentScores)
            Case "4"
                ResetRecentScores(RecentScores)
        End Select
    Loop Until Choice = "q"
End Sub

如果有帮助，这里是完整的代码：

 'Skeleton Program code for the AQA COMP1 Summer 2014 examination
 'this code should be used in conjunction with the Preliminary Material
 'written by the AQA COMP1 Programmer Team
 'developed in the Visual Studio 2008 (Console Mode) programming environment (VB.NET)
Module CardPredict
Const NoOfRecentScores As Integer = 3
Structure TCard
    Dim Suit As Integer
    Dim Rank As Integer
End Structure
Structure TRecentScore
    Dim Name As String
    Dim Score As Integer
End Structure
Sub Main()
    Dim Choice As Char
    Dim Deck(52) As TCard
    Dim RecentScores(NoOfRecentScores) As TRecentScore
    Randomize()
    Do
        DisplayMenu()
        Choice = GetMenuChoice()
        Select Case Choice
            Case "1"
                LoadDeck(Deck)
                ShuffleDeck(Deck)
                PlayGame(Deck, RecentScores)
            Case "2"
                LoadDeck(Deck)
                PlayGame(Deck, RecentScores)
            Case "3"
                DisplayRecentScores(RecentScores)
            Case "4"
                ResetRecentScores(RecentScores)
        End Select
    Loop Until Choice = "q"
End Sub
Sub Main()
    Console.Write("Boo")
End Sub
Function GetRank(ByVal RankNo As Integer) As String
    Dim Rank As String = ""
    Select Case RankNo
        Case 1 : Rank = "Ace"
        Case 2 : Rank = "Two"
        Case 3 : Rank = "Three"
        Case 4 : Rank = "Four"
        Case 5 : Rank = "Five"
        Case 6 : Rank = "Six"
        Case 7 : Rank = "Seven"
        Case 8 : Rank = "Eight"
        Case 9 : Rank = "Nine"
        Case 10 : Rank = "Ten"
        Case 11 : Rank = "Jack"
        Case 12 : Rank = "Queen"
        Case 13 : Rank = "King"
    End Select
    Return Rank
End Function
Function GetSuit(ByVal SuitNo As Integer) As String
    Dim Suit As String = ""
    Select Case SuitNo
        Case 1 : Suit = "Clubs"
        Case 2 : Suit = "Diamonds"
        Case 3 : Suit = "Hearts"
        Case 4 : Suit = "Spades"
    End Select
    Return Suit
End Function
Sub DisplayMenu()
    Console.WriteLine()
    Console.WriteLine("MAIN MENU")
    Console.WriteLine()
    Console.WriteLine("1.  Play game (with shuffle)")
    Console.WriteLine("2.  Play game (without shuffle)")
    Console.WriteLine("3.  Display recent scores")
    Console.WriteLine("4.  Reset recent scores")
    Console.WriteLine()
    Console.Write("Select an option from the menu (or enter q to quit): ")
End Sub
Function GetMenuChoice() As Char
    Dim Choice As Char
    Choice = Console.ReadLine
    Console.WriteLine()
    Return Choice
End Function
Sub LoadDeck(ByRef Deck() As TCard)
    Dim Count As Integer
    FileOpen(1, "deck.txt", OpenMode.Input)
    Count = 1
    While Not EOF(1)
        Deck(Count).Suit = CInt(LineInput(1))
        Deck(Count).Rank = CInt(LineInput(1))
        Count = Count + 1
    End While
    FileClose(1)
End Sub
Sub ShuffleDeck(ByRef Deck() As TCard)
    Dim NoOfSwaps As Integer
    Dim Position1 As Integer
    Dim Position2 As Integer
    Dim SwapSpace As TCard
    Dim NoOfSwapsMadeSoFar As Integer
    NoOfSwaps = 1000
    For NoOfSwapsMadeSoFar = 1 To NoOfSwaps
        Position1 = Int(Rnd() * 52) + 1
        Position2 = Int(Rnd() * 52) + 1
        SwapSpace = Deck(Position1)
        Deck(Position1) = Deck(Position2)
        Deck(Position2) = SwapSpace
    Next
End Sub
Sub DisplayCard(ByVal ThisCard As TCard)
    Console.WriteLine()
    Console.WriteLine("Card is the " & GetRank(ThisCard.Rank) & " of " & GetSuit(ThisCard.Suit))
    Console.WriteLine()
End Sub
Sub GetCard(ByRef ThisCard As TCard, ByRef Deck() As TCard, ByVal NoOfCardsTurnedOver As Integer)
    Dim Count As Integer
    ThisCard = Deck(1)
    For Count = 1 To (51 - NoOfCardsTurnedOver)
        Deck(Count) = Deck(Count + 1)
    Next
    Deck(52 - NoOfCardsTurnedOver).Suit = 0
    Deck(52 - NoOfCardsTurnedOver).Rank = 0
End Sub
Function IsNextCardHigher(ByVal LastCard As TCard, ByVal NextCard As TCard) As Boolean
    Dim Higher As Boolean
    Higher = False
    If NextCard.Rank > LastCard.Rank Then
        Higher = True
    End If
    Return Higher
End Function
Function GetPlayerName() As String
    Dim PlayerName As String
    Console.WriteLine()
    Console.Write("Please enter your name: ")
    PlayerName = Console.ReadLine
    Console.WriteLine()
    Return PlayerName
End Function
Function GetChoiceFromUser() As Char
    Dim Choice As Char
    Console.Write("Do you think the next card will be higher than the last card (enter y or n)? ")
    Choice = Console.ReadLine
    Return Choice
End Function
Sub DisplayEndOfGameMessage(ByVal Score As Integer)
    Console.WriteLine()
    Console.WriteLine("GAME OVER!")
    Console.WriteLine("Your score was " & Score)
    If Score = 51 Then
        Console.WriteLine("WOW!  You completed a perfect game.")
    End If
    Console.WriteLine()
End Sub
Sub DisplayCorrectGuessMessage(ByVal Score As Integer)
    Console.WriteLine()
    Console.WriteLine("Well done!  You guessed correctly.")
    Console.WriteLine("Your score is now " & Score & ".")
    Console.WriteLine()
End Sub
Sub ResetRecentScores(ByRef RecentScores() As TRecentScore)
    Dim Count As Integer
    For Count = 1 To NoOfRecentScores
        RecentScores(Count).Name = ""
        RecentScores(Count).Score = 0
    Next
End Sub
Sub DisplayRecentScores(ByVal RecentScores() As TRecentScore)
    Dim Count As Integer
    Console.WriteLine()
    Console.WriteLine("Recent scores:")
    Console.WriteLine()
    For Count = 1 To NoOfRecentScores
        Console.WriteLine(RecentScores(Count).Name & " got a score of " & RecentScores(Count).Score)
    Next
    Console.WriteLine()
    Console.WriteLine("Press the Enter key to return to the main menu")
    Console.WriteLine()
    Console.ReadLine()
End Sub
Sub UpdateRecentScores(ByRef RecentScores() As TRecentScore, ByVal Score As Integer)
    Dim PlayerName As String
    Dim Count As Integer
    Dim FoundSpace As Boolean
    PlayerName = GetPlayerName()
    FoundSpace = False
    Count = 1
    While Not FoundSpace And Count <= NoOfRecentScores
        If RecentScores(Count).Name = "" Then
            FoundSpace = True
        Else
            Count = Count + 1
        End If
    End While
    If Not FoundSpace Then
        For Count = 1 To NoOfRecentScores - 1
            RecentScores(Count) = RecentScores(Count + 1)
        Next
        Count = NoOfRecentScores
    End If
    RecentScores(Count).Name = PlayerName
    RecentScores(Count).Score = Score
End Sub
Sub PlayGame(ByVal Deck() As TCard, ByRef RecentScores() As TRecentScore)
    Dim NoOfCardsTurnedOver As Integer
    Dim GameOver As Boolean
    Dim NextCard As TCard
    Dim LastCard As TCard
    Dim Higher As Boolean
    Dim Choice As Char
    GameOver = False
    GetCard(LastCard, Deck, 0)
    DisplayCard(LastCard)
    NoOfCardsTurnedOver = 1
    While NoOfCardsTurnedOver < 52 And Not GameOver
        GetCard(NextCard, Deck, NoOfCardsTurnedOver)
        Do
            Choice = GetChoiceFromUser()
        Loop Until Choice = "y" Or Choice = "n"
        DisplayCard(NextCard)
        NoOfCardsTurnedOver = NoOfCardsTurnedOver + 1
        Higher = IsNextCardHigher(LastCard, NextCard)
        If Higher And Choice = "y" Or Not Higher And Choice = "n" Then
            DisplayCorrectGuessMessage(NoOfCardsTurnedOver - 1)
            LastCard = NextCard
        Else
            GameOver = True
        End If
    End While
    If GameOver Then
        DisplayEndOfGameMessage(NoOfCardsTurnedOver - 2)
        UpdateRecentScores(RecentScores, NoOfCardsTurnedOver - 2)
    Else
        DisplayEndOfGameMessage(51)
        UpdateRecentScores(RecentScores, 51)
    End If
End Sub
End Module

提前致谢， 埃德

Answer 1

您必须指定启动对象才能找到Sub Main。在您的情况下，这是模块 CardPredict

前往

Project>[Your project] Properties>Application Tab

然后在那里设置Startup Object。

我猜您在发生此错误之前将您的Module1（默认）重命名为CardPredict？

以后如果你想重命名一个类/模块/方法名，只需右键单击它并选择重命名。然后，这会将您项目中 this 的所有实例重命名为新名称。

Answer 2

我在做一个项目时遇到了同样的问题，我是这样解决的：

Project > ProjectName Properties > Application

将startup Object 更改为Form 1，或启动表单的名称。

Answer 3

我在构建应用程序时遇到了同样的错误；它表示我的 DLL 缺少 Sub Main。

由于某种原因，此 DLL 的应用程序类型已设置为 Windows 窗体应用程序。改回类库解决了这个问题。

Project > Project's DLL Properties > Application

Answer 4

在我的情况下，项目中缺少 Application.xaml 和 Application.xaml.vb。

由于未包含它们，因此构建工具不会生成在项目属性选项卡中设置的Sub Main 方法。

Answer 5

如果您的解决方案中没有 main：

Right click your project > Properties > Application tab > Application Type

应该是类库（可能是其他）；启动对象应为 (None)。