C#WinForm代表n个子表单 [英] c# winform delegates for n subforms

问题描述

我有一个C#主表单，可以在单独的选项卡中打开C#子表单.每个选项卡只是相同子表单的一个实例，因此选项卡代码如下:

I have a C# main form that opens up C# sub forms in separate tabs. Each tab is simply an instance of the same sub form so the tab code is like:

SubForm sf = new SubForm();
TabPage tp = new TabPage();
tp.Controls.Add(sf);
tabControl.TabPages.Add(tp);

可以有n个选项卡和子表单.然后，每个新的子窗体实例都有一个委托来处理外部事件更新，如下所示:

There can be n tabs and subforms. Then each new subform instance has a delegate to handle external event updates, like so:

public partial class SubForm : Form
{
  ... form setup ...      

  internal void DoStuff(value v)
  {
    if (InvokeRequired)
    {
        // Generic Action delegate
        Invoke(new Action<string, string>(DoStuff), value);
        return;
    }

    myLabel.Text = value;
    Show();
  }
}

单击订阅按钮，子表单中的特定键进行了Geode注册，并且该委托作为事件处理程序被传递:

Click the subscribe button and there's a Geode registration to specific keys in the subform, and the delegate is passed as an event handler:

private void button_Click(object sender, EventArgs e)
{
  new Geode().RegisterMyListener(cache, key, DoStuff);
}

更新Geode键值后，便会处理更新.

When the Geode key value is updated then the update is handled.

这对于第一个子窗体工作正常.然后，使用第二或第三子窗体，每个子窗体的键的所有Geode订阅都将更新，但是所有更新仅由最近实例化的子窗体的委托处理.我没想到会发生这种情况，因为每个新的子窗体实例都没有带有新委托的自己的堆栈吗?

This is working fine for the 1st subform. Then with a 2nd or 3rd subform all the Geode subscriptions to each subform's keys are updating, but all the updates are being handled only by the most recently instantiated subform's delegate. I had not expected that to happen because doesn't each new subform instance have its own stack with a new delegate?

更新:将第二个密钥注册到Geode RegisterMyListener后，如下所示:

UPDATE: Once a 2nd key is registered with Geode RegisterMyListener like this:

region.GetSubscriptionService().RegisterKeys(s);
region.AttributesMutator.SetCacheListener(new Listener<string, string>(DoStuff)); 

然后，每个事件更新都引用最新的DoStuff委托，而不引用以前的委托. Geode监听器是static寄存器?我希望能够使用同一Listener的许多实例来预订单独的密钥.那可能吗?还是我需要多个子窗体的多个侦听器?

then every event update references the latest DoStuff delegate and never a previous one. So is a Geode listener a static register? I am looking to be able to subscribe to separate keys with many instances of the same Listener. Is that possible? Or am I going to need multiple listeners for multiple subforms?

推荐答案

您可以使用以下扩展方法来做到这一点:

You can do it with extension method like this:

public static class Extensions
{
    public static void InvokeAction(this Control control, Action action)
    {
        if (control.InvokeRequired)
        {
            control.Invoke(new MethodInvoker(() => { action(); }));
        }
        else
        {
            action();
        }
    }
}

用法:

public partial class SubForm : Form
{
    public void SetExampleText(string text)
    {
        this.InvokeAction(() => { this.ExampleTextBox.Text = text; })
    }
}

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