C＃从窗体传递keydown到usercontrol

debugcn 发表于 Dev

VAAA

我有一个计算器用户控件，该用户控件以我的形式添加到面板中：

在我的主要表格上，我有：

 private void frmPOS_KeyDown(object sender, KeyEventArgs e)
        {
            // here I want to pass the keydown captured to my calculator
            // usercontrol so the KeyDown event is fired in my usercontrol
        }

在我的Calculator.cs中，我有：

private void Calculator_KeyDown(object sender, KeyEventArgs e)
        {
            switch (e.KeyCode)
            {
                case Keys.NumPad0:
                    // one
                    lblResult.Text = "0";
                    break;
                case Keys.NumPad1:
                    // one
                    lblResult.Text = "1";
                    break;
                case Keys.NumPad2:
                    // two
                    lblResult.Text = "2";
                    break;
                // .. etc
                case Keys.Add:
                    // Plus
                    break;
                default:
                    // Avoid setting e.Handled to                 
                    return;
            }
            e.Handled = true;
        }

有什么线索吗？

安尼什

我这样做的一种方法是在用户控件上创建一个事件，并在实际事件发生时引发它。因此，在用户控件中，我将执行以下操作...

public partial class Calculator : UserControl
{
    //create an event
    public event EventHandler<KeyPressEventArgs> OnKeyPressed;

    public Calculator()
    {
        InitializeComponent();
    }

    private void Calculator_KeyPress(object sender, KeyPressEventArgs e)
    {
        //raise the event when the key press happens and someone is listening
        if (OnKeyPressed != null)
        {
            OnKeyPressed(sender, e);
        }
    }
}

然后在主窗体上，您将订阅该事件并进行处理。

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        //subscribe to the event we create on the user control
        calculator1.OnKeyPressed += new EventHandler<KeyPressEventArgs>(MyKeyPressHandlerInMainForm);
    }

    private void MyKeyPressHandlerInMainForm(object sender, KeyPressEventArgs e)
    {
        //Handle the event. Here you would write your logic.
        //Since you have keypressEventArgs coming in as a parameter you would be able to 
        //do determine what key was pressed and all that.
    }
}

enter code here

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