主页 / user-3750058

Tim Makins's questions

Martin Hope
Tim Makins
Asked: 2023-10-06 19:50:32 +0800 CST
  • 7

我是 Delegates 的新手，正在尝试将以下 C# 代码转换为 Vb.Net。

原始C#代码：

    public delegate void delConnectionStatusChanged(EventDrivenTCPClient sender, ConnectionStatus status);
    public event delConnectionStatusChanged ConnectionStatusChanged;
    private ConnectionStatus _ConStat;

    public ConnectionStatus ConnectionState
    {
        get
        {
            return _ConStat;
        }
        private set
        {
            bool raiseEvent = value != _ConStat;
            _ConStat = value;
            if (ConnectionStatusChanged != null && raiseEvent)
                ConnectionStatusChanged.BeginInvoke(this, _ConStat, new AsyncCallback(cbChangeConnectionStateComplete), this);
        }
    }


    private void cbChangeConnectionStateComplete(IAsyncResult result)
    {
        var r = result.AsyncState as EventDrivenTCPClient;
        if (r == null)
            throw new InvalidOperationException("Invalid IAsyncResult - Could not interpret as a EDTC object");
        r.ConnectionStatusChanged.EndInvoke(result);
    }

转换为Vb.Net代码：

    Public Delegate Sub delConnectionStatusChanged(ByVal sender As EventDrivenTCPClient, ByVal status As ConnectionStatus)
    Public Event ConnectionStatusChanged As delConnectionStatusChanged
    Private _ConStat As ConnectionStatus

    Public Property ConnectionState As ConnectionStatus
        Get
            Return _ConStat
        End Get
        Private Set(ByVal value As ConnectionStatus)
            Dim [raiseEvent] As Boolean = value <> _ConStat
            _ConStat = value
            If ConnectionStatusChanged IsNot Nothing AndAlso [raiseEvent] Then ConnectionStatusChanged.BeginInvoke(Me, _ConStat, New AsyncCallback(AddressOf cbChangeConnectionStateComplete), Me)
        End Set
    End Property


    Private Sub cbChangeConnectionStateComplete(ByVal result As IAsyncResult)
        Dim r = TryCast(result.AsyncState, EventDrivenTCPClient)
        If r Is Nothing Then Throw New InvalidOperationException("Invalid IAsyncResult - Could not interpret as a EDTC object")
        r.ConnectionStatusChanged.EndInvoke(result)
    End Sub

完整的源代码和转换可以在以下位置查看： https: //pastebin.com/LuvqDvtM

转换后，我收到相同的行错误：

    r.ConnectionStatusChanged.EndInvoke(result)

和

    ConnectionStatusChanged.BeginInvoke(Me, _ConStat, New AsyncCallback(AddressOf cbChangeConnectionStateComplete), Me)

错误 BC32022“公共事件 ConnectionStatusChanged As EventDrivenTCPClient.delConnectionStatusChanged”是一个事件，无法直接调用。使用“RaiseEvent”语句引发事件。

因此，我了解到该行是一个事件，我可以使用“RaiseEvent”语句来代替，但我不明白该行实际上在做什么，或者“RaiseEvent”的处理程序应该是什么。

vb.net