Question

我尝试在Form2中向Listbox添加项目，但是注意无法添加，当我将listbox放在同一个表单中时，哪个线程运行良好...有人可以帮助它使用Form2吗？这是代码：

Public Class Form1
    Dim testthread As Threading.Thread
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Control.CheckForIllegalCrossThreadCalls = False
        testthread = New Threading.Thread(AddressOf testira)
        testthread.Start()
    End Sub
    Sub testira()
        Form2.ListBox1.Items.Add(TextBox1.Text)
    End Sub
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Form2.Show()
    End Sub
End Class

Answer 1

这是一个例子......

Public Class Form1

    Private f2 As New Form2
    Private Delegate Sub AddItemDelegate(ByVal item As String)
    Private Delegate Function GetTextboxTextDelegate(ByVal TB As TextBox) As String

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim testthread As New Threading.Thread(AddressOf testira)
        testthread.Start()
    End Sub

    Sub testira()
        Dim item As String = GetTextboxText(TextBox1)
        AddItem(item)
    End Sub

    Private Function GetTextboxText(ByVal TB As TextBox) As String
        If TB.InvokeRequired Then
            Return TB.Invoke(New GetTextboxTextDelegate(AddressOf GetTextboxText), New Object() {TB})
        Else
            Return TB.Text
        End If
    End Function

    Private Sub AddItem(ByVal item As String)
        If Me.InvokeRequired Then
            Me.Invoke(New AddItemDelegate(AddressOf AddItem), New Object() {item})
        Else
            If IsNothing(f2) OrElse f2.IsDisposed Then
                f2 = New Form2
            End If
            f2.ListBox1.Items.Add(item)
        End If
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        If IsNothing(f2) OrElse f2.IsDisposed Then
            f2 = New Form2
        End If
        f2.Show()
    End Sub

End Class

如何通过Form1中的线程从Form2与Listbox进行交互

1 个答案: