Let's say I have two forms. When I press a button on the first one, the second one is shown. However I want to be able to close the second one by pressing a button on it BUT IT SHOULD FIRE A METHOD on the first one which is responsible of closing the second window. It has to be done using delegates and events. How can I do it? Thanks for the help.
your question is not so much clear.. may be it helps you.
// Form1 is the 1st form or main form
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
//creat a sample object of FormEXt
var form = new FormExt();
//subscribe its CustomClose Event
form.CustomClose += new FormExt.CloseMeDelegate(form_CustomClose);
//set the text
form.Text = "Samplee 01";
//show the form
form.Show();
//repeat a again
form = new FormExt();
form.CustomClose += new FormExt.CloseMeDelegate(form_CustomClose);
form.Text = "Samplee 02";
form.Show();
}
void form_CustomClose(Form form)
{
//get the form show the titile
MessageBox.Show("Going to Close" + form.Text);
//close the form
form.Close();
}
}
//second form with a button
public class FormExt : Form
{
//creat a delegate which takes form as input
public delegate void CloseMeDelegate(Form form);
//creat event from delegeate set it fake delegate in order to avoid null excpetion
public event CloseMeDelegate CustomClose = delegate {
};
public FormExt() {
//creat a button
var button = new Button() { Text = "Click" , Top = 10 , Left=10 };
//grab button click event
button.Click += delegate
{
//invoke custome close event
CustomClose(this);
};
//add button on the form
this.Controls.Add(button);
}
}
In your second window, declare an event that is raised whenever the window wants to issue to be closed:
// ## Second window ##
public delegate void IssueCloseDelegate(object sender, EventArgs e);
public event IssueCloseDelegate IssueClose;
When the close button is pressed, raise this event:
// ## Second window, button click handler
if (IssueClose != null)
IssueClose(this, EventArgs.Empty);
When you instantiate the window in the first window, register the event and handle it:
// ## First window ##
//some method
var newWindow = new SecondWindow();
newWindow.IssueClose += NewWindow_IssueClose;
newWindow.Show();
//...
private void NewWindow_IssueClose(object sender, EventArgs e)
{
var closedWindow = (SecondWindow)sender;
closedWindow.Close();
}
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