Passing variable between winforms
I have a problem concerning delegates in a Windows.Forms application.
There are two forms:
the main form, which has a button named "Settings".
the "settings" form, this is the "child" form.
When I click the "Settings" button in the main form, it opens an instance of the Settings form.
My problem is that I need to pass a variable to the Settings form, when I open it. So that the new form will show the variable text. I don't know how to retrieve the information in the child "Settings" form. I did this by following a tutorial online and could not understand from the tutorial how to read the info in the destination form.
Here's what I've done so far, the code in the main form:
public partial class MainForm : Form
{
/// <summary>
/// delegate to send data between forms
/// </summary>
public delegate void PageInfoHandler(object sender, PageInfoEventArgs e);
/// <summary>
/// event of the delegate
/// </summary>
public event PageInfoHandler PageInfoRetrieved;
//other stuff, events blabla
private void toolStripBtnSettings_Click(object sender, EventArgs e)
{
PageInfoEventArgs args = new PageInfoEventArgs(SomeString);
this.OnPageInfoRetrieved(args);
SettingsForm settingsForm = new SettingsForm();
settingsForm.ShowDialog();
}
private void OnPageInfoRetrieved(PageInfoEventArgs args)
{
if (PageInfoRetrieved != null)
PageInfoRetrieved(this, args);
}
}
Pass any information you want to in to the constructor of Settings form, and provide accessor methods for things you need out of there.
public class SettingsForm : WinForm
{
private string m_Data;
private int m_nExample = 0;
// ctor
public SettingsForm(string _data)
{
m_Data = data; // you can now use this in SettingsForm
} // eo ctor
public int Example {get{return(m_nExample);} }
} // eo class SettingsForm
In the above "example" you can construct a SettingForm with a string and get at an integer it may use. In your code:
private void toolStripBtnSettings_Click(object sender, EventArgs e)
{
PageInfoEventArgs args = new PageInfoEventArgs(SomeString);
this.OnPageInfoRetrieved(args);
SettingsForm settingsForm = new SettingsForm("some data to pass");
settingsForm.ShowDialog();
int result = settingsForm.Example; // retrieve integer that SettingsForm used
}
The Setttings form is a class. It's yours now and you can do what you like with it. So add a parameter (or however many you want) to its constructor. Then in your MainForm call SettingsForm(whatever) and you're all set.