Question

There is a child textbox control in an chlid window form created by main window form using thread technology, and I wanna implement this function: In the child window form, when I click a button (or Enter-key-down), it pass the text to the main window form. What can I do about that?

Answer 1

You need a way for the ChildWindow to send a message back to MainWindow. Following example should be useful:

Code:

An Interface to allow “communication” between windows

public interface IListner
{
    void Send(String message);
}

MainWindow

public partial class MainWindow : Window, IListner
{
    public MainWindow()
    {
        InitializeComponent();
    }

    public void Send(string message)
    {
        // Read the message here.
        // If this code is called from different thread, use "Dispatcher.Invoke()"
    }

    public void OpenAnotherWindow()
    {
        // Since "MainWindow" implements "IListner", it can pass it's own instance to "ChildWindow"
        ChildWindow childWindow = new ChildWindow(this);
    }  
}

ChildWindow:

public partial class ChildWindow : Window
{
    private IListner Listner { get; set; }

    public ChildWindow(IListner listner)
    {
        InitializeComponent();

        Listner = listner;
    }

    private void OnTextBoxTextChanged()
    {
        // This will call "Send" on "MainWindow"
        Listner.Send(TextBox1.Text);
    }
}