C＃用户控件按钮单击事件处理程序来调用主窗体的功能 [英] C# user control button click event handler to call a function from main form

问题描述

我有一个表格和一个用户控件。在我的用户我有一个按钮，我想打电话给从形式的方法。在C＃谁能帮助？

I have a Form and a UserControl. In my UserControl I have a button, and I would like to call a method from the Form. Can anyone help in C#?

推荐答案

您需要创建的用户控件的按钮事件的事件处理程序，并从火了。实际按钮的Click事件

You need to create an event handler for the button-event of the usercontrol and fire it from the click event of the actual button.

class MyControl : UserControl
{
    public delegate void ButtonClickedEventHandler(object sender, EventArgs e);
    public event ButtonClickedEventHandler OnUserControlButtonClicked;
}

现在你要听实际按钮的情况下， >

Now you need to listen to the event of the actual button:

class MyControl : UserControl
{
    // See above

    public MyControl()
    {
        _myButton.Clicked += new EventHandler(OnButtonClicked);
    }

    private void OnButtonClicked(object sender, EventArgs e)
    {
        // Delegate the event to the caller
        if (OnUserControlButtonClicked != null)
            OnUserControlButtonClicked(this, e);
    }
}

从主窗体（老板），你现在可以听事件：

From the main form (owner) you can now listen to the event:

public FancyForm : Form
{
    public FancyForm()
    {
        _myUserControl.OnUserControlButtonClicked += new EventHandler(OnUCButtonClicked);
    }

    private void OnUCButtonClicked(object sender, EventArgs e)
    {
        // Handle event from here
        MessageBox.Show("Horray!");
    }
}

更新：这两种实现方式甚至可以安全使用Lambda表达式和默认EventHandler委托定义的几行代码

Update: Both implementations can even safe a few lines of code by using Lambdas and default EventHandler delegate definitions.

class MyControl : UserControl
{    
    public event EventHandler OnUserControlButtonClicked;
    // Use this, if you want to use a different EventArgs implementation:
    // public event EventHandler<CustomEventArgs> OnUserControlButtonClicked; 

    public MyControl()
    {
        _myButton.Clicked += (s, e) => 
        {
            if (OnUserControlButtonClicked != null)
                OnUserControlButtonClicked(this, e);
        }
    }
}

public FancyForm : Form
{
    public FancyForm()
    {
        _myUserControl.OnUserControlButtonClicked += (s, e) => MessageBox.Show("Horray!");
    }
}

更新2 ：安全更行与C＃6功率：

Update 2: Safe even more lines with the power of C# 6:

class MyControl : UserControl
{    
    public event EventHandler OnUserControlButtonClicked;

    public MyControl()
    {
        _myButton.Clicked += (s, e) => this.OnUserControlButtonClicked?.Invoke(this, e);
    }
}

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