Question

我有一个类来处理用于从Scanner接收数据的串口，并在串口缓冲区中有数据时引发事件：

Imports System
Imports System.IO.Ports

Public Class CommManager
' Here is settings for serial port
    Public Event HaveScannerData(ByVal e As String)
    Private Sub ProcessDataReceived(ByVal DataReceived As String)
        'This sub happens when there is data in the buffer and data is Input_String
            RaiseEvent HaveScannerData(Input_String)
    End Sub 
End Class

然后在表单中，我想使用此事件在标签框中显示它。我用：

Private WithEvents ScannerPort As New CommManager

Private Sub OnHaveSerialPortData(ByVal Compelete_Data_Received) Handles ScannerPort.HaveScannerData
    Label1.Text = Compelete_Data_Received
End Sub

问题是我收到此错误消息：跨线程操作无效：控制从其创建的线程以外的线程访问的“Label1”。我知道我必须使用Invoke和Delegate，但我不知道如何。请帮我。感谢

Answer 1

我过去曾遇到过这个问题。用OnHaveSerialPortData替换你的代码：

If Label1.InvokeRequired Then Label1.Invoke(Sub() Label1.Text = Compelete_Data_Received) else Label1.Text = Compelete_Data_Received

这应该处理来自主线程或不同线程的label1文本更改。

VB.net 2008使用Form Cross-thread错误中的类的事件输出

1 个答案: