如何将数据从一个表单传递到多个表单 VB.net答案

【问题标题】：How to pass data from one form to multiple forms VB.net如何将数据从一个表单传递到多个表单 VB.net
【发布时间】：2017-01-02 07:05:27
【问题描述】：

我的 Form1 看起来像这样获取文本框的值以将数据传递给多个表单。：

Public Class Form1

Public username As String

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    username = TextBox1.Text
    Form2.Show()
    Me.Close()
End Sub
End Class

在第二个表单中，我使用此代码显示从 Form1 输入的用户名数据。：

Public Class Form2

Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Label1.Text = "Hi " & Form1.username & "!"
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Form3.Show()
    Me.Close()
End Sub
End Class

效果很好。数据以第二种形式出现。但在Form3中，它只显示“Form1”

Form3代码：

Public Class Form3

Private Sub Form3_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Label2.Text = Form1.username
End Sub

我应该怎么做才能让用户名的数据显示在多个表单上？

【问题讨论】：

标签： vb.net forms winforms visual-studio

【解决方案1】：

不要使用表单的默认实例，为表单创建以用户名作为参数的构造函数，然后显式创建表单

Public Class Form3
    Private _username As String
    Public Sub New(username As String)
        _username = username
    End Sub

    Private Sub Form3_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Label2.Text = _username
    End Sub
End Class

Public Class Form2
    Private _username As String
    Public Sub New(username As String)
        _username = username
    End Sub

    Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Label1.Text = $"Hi {_username}!"
    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim formThree As new Form3(_username)
        formThree.Show()
        Me.Close()
    End Sub
End Class

Public Class Form1
    Private _username As String

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim formThree As new Form3(TextBox1.Text)
        formThree.Show()
        Me.Close()
    End Sub
End Class

使用这种方法，您无需将用户名公开为 Form1 的公共属性。

【讨论】：