Question

我是学习Visual Basic的新程序员。
现在，我正在做一个有关垒球记分牌的项目。我只用过文字，所以我没有意识到我的老师想要常量。

但是我很困惑，因为我不确定2的区别还是不确定如何将文字转换为常量。

如果您能提供帮助，我将不胜感激。谢谢。

Public Class frmSoftballScoreboard
    'Declaring array
    Dim scores(7) As Double
    'declaring variables
    Dim runs As String
    Dim runningScore As Integer = 0
    Dim i As Integer = 0
    Dim out As Double

    'page load event
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        lstScores.Items.Add("Runs Running Score")
    End Sub
    'Enter score button
    Private Sub btnScore_Click(sender As Object, e As EventArgs) Handles btnScore.Click

        If i < 7 Then
            'display inputbox to the user
            runs = InputBox("Enter score for " & (i + 1) & " innings", "Score")
            'if runs is entered
            If runs <> "" Then
                'parse the value of runs
                If (Double.TryParse(runs, out)) Then
                    'parse the runs and add it to the array scores()
                    scores(i) = Double.Parse(runs)
                    runningScore += scores(i)
                    'add the rainfall value to the listbox along with month name
                    lstScores.Items.Add(scores(i) & " :" & runningScore)
                    'increment the value of i
                    i = i + 1
                Else
                    'display error message
                    MessageBox.Show("Enter valid runs value")
                    lblTotal.Text = ""
                End If
            Else
                'if runs is empty then display error message
                MessageBox.Show("Enter runs for " & i & "innings")
            End If
        Else
            MessageBox.Show("Only sever innings are allowed")
        End If
        'calculate total runs And display on the lable
        lblTotal.Text = String.Format("final score is {0}", scores.Sum())
    End Sub
    'Clear Menu click
    Private Sub ClearToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles mnuClear.Click
        lstScores.Items.Clear()
        lblTotal.Text = ""
        'reset i to 0
        i = 0
    End Sub
    'Exit Menu click
    Private Sub ExitToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles mnuExit.Click
        'close application
        Application.Exit()
    End Sub
End Class

Answer 1

下面是一个示例。

带有文字的旧代码：

MessageBox.Show("All well done!")

使用常量代替代码：

Const SUCCESS_MESSAGE As String = "All well done!"

MessageBox.Show(SUCCESS_MESSAGE)

在常量中带有占位符的示例：

Const REPLACE_MESSAGE_SAMPLE As String = "This is Number #!"

Dim i As Integer
i = 123

MessageBox.Show(REPLACE_MESSAGE_SAMPLE.Replace("#", i))

您可以使用任何喜欢的字符串代替#。这只是一个示例。

顺便说一句：您的代码看起来像VB.NET，而不是VBA。我编辑了。

Answer 2

您应该使用带占位符的常量：

Const WARNING_MESSAGE$ = "The player {0} must be ready at {1}"
MsgBox(String.Format(WARNING_MESSAGE, "John Davis", #12/11/2018#))

将文字转换为常量

2 个答案: