从另一个类和线程更新UI项 [英] Update UI item from another class and thread

问题描述

我在这里还看到了其他类似的问题，但似乎找不到针对我特定问题的解决方案.

I've seen other similar questions here but I can't seem to find a solution for my specific problem.

我正在写一个Twitch Bot，当从服务器收到消息时，需要更新主窗体上的列表框.我在TwitchBot.cs类中创建了一个名为OnReceive的自定义事件，如下所示:

I'm writing a Twitch Bot and need to update a listbox on the main form when a message is received from the server. I made a custom event in my TwitchBot.cs class called OnReceive that looks like this:

public delegate void Receive(string message);
public event Receive OnReceive;

private void TwitchBot_OnReceive(string message)
{
    string[] messageParts = message.Split(' ');
    if (messageParts[0] == "PING")
    {
        // writer is a StreamWriter object
        writer.WriteLine("PONG {0}", messageParts[1]);
    }
}

该事件在我的TwitchBot类的Listen()方法中引发:

The event is raised in the Listen() method of my TwitchBot class:

private void Listen()
{
    //IRCConnection is a TcpClient object
    while (IRCConnection.Connected)
    {
        // reader is a StreamReader object.
        string message = reader.ReadLine();

        if (OnReceive != null)
        {
            OnReceive(message);
        }
    }
}

连接到IRC后端时，我从新线程调用Listen()方法:

When connecting to the IRC back-end, I call the Listen() method from a new thread:

Thread thread = new Thread(new ThreadStart(Listen));
thread.Start();

然后，我使用以下行以主要形式订阅OnReceive事件:

I then subscribed to the OnReceive event in the main form using the following line:

// bot is an instance of my TwitchBot class
bot.OnReceive += new TwitchBot.Receive(UpdateChat);

最后，UpdateChat()是主要形式的方法，用于更新其上的列表框:

Finally, UpdateChat() is a method in the main form used to update a listbox on it:

private void UpdateChat(string message)
{
    lstChat.Items.Insert(lstChat.Items.Count, message);
    lstChat.SelectedIndex = lstChat.Items.Count - 1;
    lstChat.Refresh();
}

当我连接到服务器并且Listen()方法运行时，我得到一个InvalidOperationException，上面写着其他信息:跨线程操作无效:控制'lstChat'是从不是该线程的线程访问的创建于".

When I connect to the server and the Listen() method runs, I get an InvalidOperationException that says "Additional information: Cross-thread operation not valid: Control 'lstChat' accessed from a thread other than the thread it was created on."

我已经研究了如何从不同的线程更新UI，但是只能找到WPF的东西，而我正在使用winforms.

I've looked up how to update UI from a different thread but can only find things for WPF and I'm using winforms.

推荐答案

您应检查 Invoke for UI thread

private void UpdateChat(string message)
{
    if(this.InvokeRequired)
    {
        this.Invoke(new MethodInvoker(delegate {
            lstChat.Items.Insert(lstChat.Items.Count, message);
            lstChat.SelectedIndex = lstChat.Items.Count - 1;
            lstCat.Refresh();
        }));           
    } else {
            lstChat.Items.Insert(lstChat.Items.Count, message);
            lstChat.SelectedIndex = lstChat.Items.Count - 1;
            lstCat.Refresh();
    }
}

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