Question

我正在尝试将数据输入3个单独的文本框中，通过我的日期信息类和重新格式化的打印传递该数据。我似乎无法弄清楚如何引用输入文本框的数据。我以为我写得正确，但所有打印出的都是0/0/0。

以下是我的form1

中的代码

Public Class Form1

Private Sub btnFormat_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFormat.Click
    Dim enteredDate As New DateInformation
    txtBoxResult.Text = ""
    txtBoxResult.AppendText(enteredDate.ToString)
End Sub

这是DateInformation类

Public Class DateInformation

Private month As Integer
Private day As Integer
Private year As Integer
Private frmone As New Form1

Public Sub New(ByVal initialmonth As Integer, ByVal initialday As Integer, ByVal initialyear As Integer)
    month = initialmonth
    day = initialday
    year = initialyear
End Sub

Sub New()
    ' TODO: Complete member initialization 
End Sub

Public Property sourceForm() As Form1
    Get
        Return frmone
    End Get
    Set(ByVal Value As Form1)
        frmone = Value
    End Set
End Property

Public Property newmonth() As Integer
    Get
        Return month
    End Get
    Set(ByVal value As Integer)
        Try
            value = Convert.ToInt32(frmone.txtBoxMonth.Text)
        Catch ex As Exception
            MessageBox.Show("Value entered must be an integer")
        End Try
        value = month
    End Set
End Property


Public Overrides Function ToString() As String
    Return month & "/" & day & "/" & year
End Function

Answer 1

您的代码正在调用DateInformation的无参数构造函数（没有参数的那个，并且您已使用TODO注释标记）。在此上下文中，内部变量month，day和year设置为其初始默认值，对于整数，该值为0。当然，ToString覆盖打印0/0/0。

要解决您的问题，您需要调用带有3个参数的DateInformation构造函数

假设您有3个名为txtMonth的文本框，txtDay和txtYear正确的代码是

Private Sub btnFormat_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFormat.Click
    Dim year as Integer
    Dim month as Integer
    Dim day as Integer

    if Not int32.TryParse(txtYear, year) Then
       MessageBox.Show("Enter a number for year")
       return
    End If 
    if Not int32.TryParse(txtMonth, month) Then
       MessageBox.Show("Enter a number for month")
       return
    End If 
    ' other checks for a valid month to follow here...

    if Not int32.TryParse(txtYear, day) Then
       MessageBox.Show("Enter a number for days")
       return
    End If 
    ' other checks for a valid days to follow here...

    Dim enteredDate As New DateInformation(month, day, year)
    txtBoxResult.Text = ""
    txtBoxResult.AppendText(enteredDate.ToString)
End Sub

这里我已经对你的类外部的日，月和年进行了检查，因为你需要在调用类构造函数之前检查用户输入的文本（字符串）是否真的是一个整数。您可以为有效的月份和日期添加其他检查。

如何使用在单独的类中的文本框中输入的数据

1 个答案: