[英]Windows Forms Event Subscription c#
I have a sample form with 3 windows. 我有一个带有3个窗口的示例表单。 Each window has a label and the main form has a button.
每个窗口都有一个标签,主窗体有一个按钮。
I have a class with the following code: 我有一个包含以下代码的类:
public class CustomEventArgs : EventArgs
{
public string Message { get; set; }
public CustomEventArgs(string message)
{
Message = message;
}
}
public delegate void CustomEventHandler(object sender, CustomEventArgs args);
public class EventCode
{
public void Process()
{
var cea = new CustomEventArgs("I was processed");
if (MyEvent != null)
{
MyEvent.Invoke(this, cea);
}
}
public event CustomEventHandler MyEvent;
}
On my main form, I am going to push the button and have it process code in my EventCode class, and then invoke the event. 在我的主窗体上,我将按一下按钮,让它在EventCode类中处理代码,然后调用事件。 I want the event to send a message to both forms that are open, which will then display a message on the screen.
我希望事件将消息发送到两个打开的窗体,然后它们将在屏幕上显示一条消息。
Here is my button click code in Form1: 这是我在Form1中的按钮单击代码:
private void Form1_Load(object sender, EventArgs e)
{
Window1 w1 = new Window1();
w1.Show();
Window2 w2 = new Window2();
w2.Show();
}
private void button1_Click(object sender, EventArgs e)
{
EventCode ec = new EventCode();
ec.Process();
}
In Window 1: 在窗口1中:
EventCode ec = new EventCode();
public Window1()
{
InitializeComponent();
ec.MyEvent += new CustomEventHandler(ec_MyEvent);
}
void ec_MyEvent(object sender, CustomEventArgs args)
{
label1.Text = args.Message;
}
Repeated for Window 2 对窗口2重复
When I click on the button, the event subscription does not display the text on each of the forms. 当我单击按钮时,事件订阅不会在每个表单上显示文本。 If i create an event subscription on the main form, it will display.
如果我在主窗体上创建事件订阅,它将显示。
I am not sure which route to take to make this functionality to work. 我不确定要使该功能正常工作应采取的路线。
Thoughts? 思考?
Subscriptions to events only work for the instances you subscribe on. 订阅事件仅适用于您订阅的实例。 If you create a new instance of EventCode and subscribe to the events, the event will only be raised if you call Process on that specific instance.
如果您创建EventCode的新实例并订阅事件,则仅当您在该特定实例上调用Process时,才会引发该事件。
Quick solution: pass the EventCode instance you create in the main window to the two child windows. 快速解决方案:将您在主窗口中创建的EventCode实例传递给两个子窗口。
public Window1(EventCode eventCode)
{
InitializeComponent();
eventCode.MyEvent += new CustomEventHandler(ec_MyEvent);
}
void ec_MyEvent(object sender, CustomEventArgs args)
{
label1.Text = args.Message;
}
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