在写vb.net时,遇到要在线程里改变form上的listview控件中的信息,动手做起来才发现并不是那么容易。因为微软的框架并不鼓励在线程里直接访问form上的控件。因为这样会改变ui进程的正常执行。如果必须这样做,需要在线程中使用invoke函数或者invokebegin函数。下面是一个例子:
Imports System.Threading
Public Class Form1
Delegate Sub AddListItem(ByVal IPString As String, ByVal ScanPort As Integer)
Public myDelegate As AddListItem
Public OpenPortCount As Integer = 0
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
myDelegate = New AddListItem(AddressOf AddListItemMethod)
End Sub
Private Sub Start_Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Start_Button.Click
Dim mythread As Thread
mythread = New Thread(New ThreadStart(AddressOf ThreadFunction))
mythread.Start()
立即进入“豆包AI人工智官网入口”;
立即学习“豆包AI人工智能在线问答入口”;
End Sub
Private Sub ThreadFunction()
Dim mythread As Thread
mythread = New Thread(New ThreadStart(AddressOf DoScanThread))
mythread.Start()
End Sub 'ThreadFunction
Private Sub DoScanThread()
Dim myThreadClassObject As New ScanThreadClass(Me)
myThreadClassObject.run()
End Sub
Public Sub AddListItemMethod(ByVal IPString As String, ByVal scanport As Integer)
ListView_Result.Items.Add(IPString, OpenPortCount) 'ScanIP.ToString(), 0)
ListView_Result.Items(OpenPortCount).SubItems.Add(scanport.ToString())
OpenPortCount += 1
End Sub 'AddListItemMethod
End Class
Public Class ScanThreadClass
Private myFormControl1 As Form1
Public Sub New(ByVal myForm As Form1)
myFormControl1 = myForm
End Sub 'New
Public Sub run()
myFormControl1.Invoke(myFormControl1.myDelegate, New Object() {"11", 123})
End Sub
End Class
主要注意的就是Invoke的调用和Delegate的定义。
每个人都需要一台速度更快、更稳定的 PC。随着时间的推移,垃圾文件、旧注册表数据和不必要的后台进程会占用资源并降低性能。幸运的是,许多工具可以让 Windows 保持平稳运行。
Copyright 2014-2025 https://www.php.cn/ All Rights Reserved | php.cn | 湘ICP备2023035733号