篮球计分板选No仍自动+1？VB.NET代码问题求助

问题场景 #

开发篮球计分板，主窗体显示最终得分和罚球得分，通过控制器窗体传递数据。控制器有得分和罚球的±1按钮，为简化操作，点击主得分+1按钮后弹出「是否为罚球？」的Yes/No对话框，期望：

• 选Yes：罚球得分+1
• 选No：罚球得分不加分
  但目前选No时罚球得分仍会自动+1。

原始及尝试代码 #

原始代码：

Private Sub btnT1Sp1_Click(sender As Object, e As EventArgs) Handles btnT1Sp1.Click 'Score +1
        Form1.lblT1pnts.Text = Val(Form1.lblT1pnts.Text) + 1
        MsgBox("Was this a freethrow?", vbQuestion + vbYesNo, "Controller")
        If vbYes Then
            Form1.lblFreeThrowsT1.Text = Val(Form1.lblFreeThrowsT1.Text) + 1
        Else
            Me.Close()
            Me.Dispose()
        End If
    End Sub

尝试过的修改版本：
版本1：

Private Sub btnT1Sp1_Click(sender As Object, e As EventArgs) Handles btnT1Sp1.Click 'Score +1
        Form1.lblT1pnts.Text = Val(Form1.lblT1pnts.Text) + 1
        MsgBox("Was this a freethrow?", vbQuestion + vbYesNo, "Controller")
        If vbYes Then
            Form1.lblFreeThrowsT1.Text = Val(Form1.lblFreeThrowsT1.Text) + 1
        Else
            Form1.lblFreeThrowsT1.Text = Val(Form1.lblFreeThrowsT1.Text) - 1
            Me.Close()
            Me.Dispose()
        End If
    End Sub

版本2：

Private Sub btnT1Sp1_Click(sender As Object, e As EventArgs) Handles btnT1Sp1.Click 'Score +1
        Form1.lblT1pnts.Text = Val(Form1.lblT1pnts.Text) + 1
        MsgBox("Was this a freethrow?", vbQuestion + vbYesNo, "Controller")
        If vbYes Then
            Form1.lblFreeThrowsT1.Text = Val(Form1.lblFreeThrowsT1.Text) + 1
        Elseif vbNo Then
            Me.Close()
            Me.Dispose()
        End If
    End Sub

版本3：

Private Sub btnT1Sp1_Click(sender As Object, e As EventArgs) Handles btnT1Sp1.Click 'Score +1
        Form1.lblT1pnts.Text = Val(Form1.lblT1pnts.Text) + 1
        MsgBox("Was this a freethrow?", vbQuestion + vbYesNo, "Controller")
        If vbYes Then
            Form1.lblFreeThrowsT1.Text = Val(Form1.lblFreeThrowsT1.Text) + 1
        Elseif vbNo Then
            Form1.lblFreeThrowsT1.Text = Val(Form1.lblFreeThrowsT1.Text) - 1
        End If
    End Sub

版本4：

Private Sub btnT1Sp1_Click(sender As Object, e As EventArgs) Handles btnT1Sp1.Click 'Score +1
        Form1.lblT1pnts.Text = Val(Form1.lblT1pnts.Text) + 1
        MsgBox("Was this a freethrow?", vbQuestion + vbYesNo, "Controller")
        If vbYes Then
            Form1.lblFreeThrowsT1.Text = Val(Form1.lblFreeThrowsT1.Text) + 1
        Elseif vbNo Then
            Return
        End If
    End Sub

问题根源 #

1. 未捕获MsgBox的返回值：所有代码都直接用vbYes/vbNo做判断，没有接收MsgBox的返回结果。MsgBox会返回代表用户选择的枚举值，直接写If vbYes Then相当于判断布尔值True，所以不管用户选Yes还是No，这个条件都会成立，导致罚球得分每次都+1。
2. 逻辑判断错误：部分尝试版本里的Elseif vbNo写法同样无效，本质还是没有获取到用户的实际选择结果。

修正后的代码 #

Private Sub btnT1Sp1_Click(sender As Object, e As EventArgs) Handles btnT1Sp1.Click 'Score +1
    ' 先给主得分加1
    Form1.lblT1pnts.Text = Val(Form1.lblT1pnts.Text) + 1
    ' 弹出对话框并接收用户选择结果
    Dim userChoice As DialogResult = MsgBox("Was this a freethrow?", vbQuestion + vbYesNo, "Controller")
    ' 根据用户选择执行对应操作
    If userChoice = vbYes Then
        Form1.lblFreeThrowsT1.Text = Val(Form1.lblFreeThrowsT1.Text) + 1
    End If
    ' 选No时不做罚球加分操作，直接关闭控制器窗体
    Me.Close()
    Me.Dispose()
End Sub

额外优化建议 #

• 避免直接跨窗体操作控件：可以通过属性、事件或委托传递数据，降低窗体间的耦合度。
• 替换Val为更安全的类型转换：使用Integer.TryParse处理得分转换，避免非数字文本导致的异常，示例：

Private Sub UpdateScore(scoreLabel As Label, change As Integer)
    Dim currentScore As Integer
    If Integer.TryParse(scoreLabel.Text, currentScore) Then
        scoreLabel.Text = (currentScore + change).ToString()
    End If
End Sub

调用时：

UpdateScore(Form1.lblT1pnts, 1)
If userChoice = vbYes Then
    UpdateScore(Form1.lblFreeThrowsT1, 1)
End If

内容的提问来源于stack exchange，提问作者LeakyEarth2000