当收到新消息时关闭MessageBox [英] Close MessageBox when incoming new message

问题描述

我创建了简单的应用程序来使用C＃和GsmComm库发送和接收消息。如果有新的传入消息，我的应用程序将显示messageBox新消息到达。我的问题是当我有很多新的消息时，messageBox会显示如此多的messageBox notication。如何使用代码显示最后一个单个消息框？

这个mycode：

  private void comm_MessageReceived（object sender，MessageReceivedEventArgs e）
 {
 var obj = e.IndicationObject; 
 if（obj是MemoryLocation）
 {
 var loc =（MemoryLocation）obj; 
 var msg = string.Format（存储中收到的新消息\{0} \，索引{1}。，
 loc.Storage，loc.Index）; 
 MessageBox.Show（msg）; 
 return; 
} 
} 
  

我混淆解决这个问题，我试图用另一种方式使用窗体显示新的传入的notif form1.showDialog（）; 但同样的问题首先形式show不能在新窗体打开时关闭。这是我的参考： https://stackoverflow.com/a/13445167/3319555

我非常感谢任何人都可以帮助我......谢谢

解决方案

如果您使用第二种解决方案使用 form.ShowDialog（）显示表单，您可以将表单存储在列表中。然后，当需要显示一个新表单时，可以遍历列表并使用 form.Close（）关闭每个打开的表单。假设你的comm_MessageReceieved方法在另一个线程上运行，我认为它是通过一个IO完成端口来驱动的，那么这样的事情可能是这样吗？

 列表与LT; MyForm的> formList =新列表< MyForm>（）; 
 
只读对象formListLock = new object（）; 
 
 private void comm_MessageReceived（object sender，MessageReceivedEventArgs e）
 {
 ///您需要锁定列表才能进行线程安全访问
 lock（formListLock）
 {
 ///迭代列表的副本以避免在迭代中突变列表
 foreach（formList.ToList（）中的MyForm表单）
 {
表单。 ThreadSafeClose（）; 
} 
} 
 
 string msg =message; 
 using（MyForm form = new MyForm（msg））
 {
 lock（formListLock）{formList.Add（form）; } 
 form.ShowDialog（）; 
 lock（formListLock）{formList.Remove（form）; } 
} 
} 
  

这只是我的头顶，但可能是另一个可能的方向。

您必须对form.Close（）进行线程安全调用，以便它可以在窗体的UI线程上运行。阅读有关调用此处的信息。关于这个话题有很多关于SO的信息。这可能就像在你的表单类中添加如下方法一样简单：

  public void ThreadSafeClose（）
 {
 if（this.InvokeRequired）
 {
 this.Invoke（new Action（Close））; ///或BeginInvoke ... 
} 
 else 
 {
 Close（）; 
 
 
 $ / code $ / pre 
 
 
阅读更多关于列表的信息： https://msdn.microsoft.com/en-us/library /6sh2ey19%28v=vs.110%29.aspx  
 
 
 
阅读更多关于锁定语句的信息： https://msdn.microsoft.com/en-us/library/c5kehkcz.aspx  
 
 
 
在此处阅读有关线程同步的更多信息： https： //msdn.microsoft.com/en-us/library/ms173179.aspx  
 
 
 
还有很多线程安全的集合可能可以满足您的需求，例如 ConcurrentBag 。
 
i created simple application to send and receive message using C# and GsmComm Library. if there is a new incoming message my application will show messageBox that new message arrived. my problem is when i have many new message, messageBox will show so many messageBox notication. How can I just show the last single message box using code?



this mycode:
private void comm_MessageReceived(object sender, MessageReceivedEventArgs e)
{
    var obj = e.IndicationObject;
    if (obj is MemoryLocation)
    {
        var loc = (MemoryLocation)obj;
        var msg = string.Format("New message received in storage \"{0}\", index {1}.",
                                loc.Storage, loc.Index);
        MessageBox.Show(msg);
        return;
    }
}
i confuse to fix this, i tried to another way using form to show new incoming notif form1.showDialog(); but same problem first form show cannot be closed when new form opened. this my reference: https://stackoverflow.com/a/13445167/3319555

I really thanks if anyone can help me..thanks
解决方案
If you're using your second solution of displaying a form with form.ShowDialog() you can store the forms in a list.  Then, when a new form needs to be displayed, you can iterate through the list and close each open form with form.Close().  Assuming that your comm_MessageReceieved method is run on another thread, which I assume is driven via an IO completion port, then something like this perhaps?
List<MyForm> formList = new List<MyForm>();

readonly object formListLock = new object();

private void comm_MessageReceived(object sender, MessageReceivedEventArgs e)
{
    /// you need to lock the List for thread safe access
    lock (formListLock) 
    {
        /// iterate over a copy of the list to avoid mutating the list under iteration
        foreach (MyForm form in formList.ToList())
        {
            form.ThreadSafeClose();
        }
    }

    string msg = "message";
    using (MyForm form = new MyForm(msg))
    {
        lock (formListLock) { formList.Add(form); }
        form.ShowDialog();
        lock (formListLock) { formList.Remove(form); }
    }
}
This was just off the top of my head but might be another possible direction you could take.

You will have to make a thread safe call to form.Close() so that it is run on the form's UI thread.  Read about invoke here.  There's a lot of information on SO about this topic. This could be as simple as adding something like the following method to your form class:
public void ThreadSafeClose()
{
    if (this.InvokeRequired)
    {
        this.Invoke(new Action(Close));  /// or BeginInvoke...
    }
    else
    {
        Close();
    }
}
Read more about Lists here: https://msdn.microsoft.com/en-us/library/6sh2ey19%28v=vs.110%29.aspx

Read more about the lock statement here: https://msdn.microsoft.com/en-us/library/c5kehkcz.aspx

Read more about thread synchronisation here: https://msdn.microsoft.com/en-us/library/ms173179.aspx

There are also numerous thread-safe collections that could possibly suit your needs, e.g. ConcurrentBag.

                        
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