So, the sender header is set to [email protected], to indicate the From header doesn't indicate who actually submitted the message. In this case, if the message cannot be sent, it's probably better for the agent to receive the non-delivery report, and so Return-Path would also be set to [email protected] so that any delivery reports go to it ...

I know this is a very old post but in Framework 4 you can cast the sender as a Control: Control cntrl = (Control)sender; cntrl.Text = "This is a " + sender.GetType().ToString(); Note you are only able to reference controls that all of the different controls have in common (ie Text).

2013年1月23日 · @EduardoPignatelli, The relationship between 'sender' and 'Button' in the inheritance hierarchy, is that they are both 'object' types. 'sender' is simply a wrapper for an 'object' type. When unboxed at run-time, the underlying instance of the wrapped object is projected to the capturing class. In this case 'Button'.

var rectangle = sender as Rectangle; There are two possibilities: sender is a type that can be assigned to a Rectangle, in which case, rectangle will contain a reference to the same object but typed as a Rectangle instead of just object; sender is of some other type, in which case rectangle will be null, which is caught in the following check.

2013年11月14日 · Private WithEvents Items As Outlook.Items Private Sub Application_Startup() Dim objNS As Outlook.NameSpace Set objNS = GetNamespace("MAPI") Set Items = objNS.GetDefaultFolder(olFolderInbox).Items End Sub Private Sub Items_ItemAdd(ByVal item As Object) If item.Class = olMail Then If Left$(item.Subject, 29) = "Hazard Identification Report" …

2010年9月23日 · The line simply casts sender to a CheckBox. Why? The event handler signature for the CheckedChanged event is: CheckChanged(object sender, EventArgs e) So, you need to cast sender back to a CheckBox if you want to use any CheckBox specific functionality - object doesn't have much that you can use...

2012年1月6日 · About events, the sender parameter is always the object that generated the event (for example a Button in a Click event on a button). If you want to pass arbitrary data in a custom event, inherits from EventArgs and pass it as the second argument.

2014年6月23日 · In C# you can access the sender's email address using the SendUsingAccount.SmtpAddress property of the Outlook MailItem. It returns a string object. VB.net should be similar. string sender = mail.SendUsingAccount.SmtpAddress; where mail is an Outlook.MailItem

2014年7月21日 · (object sender, XXArgs e) where XXArgs is a class that inherits from EventArgs. sender is, well, the sender of the event. In your example, if you click on a button, the button will fire the event using its own instance reference (this) for the sender parameter (so sender is a reference to your button). This is useful because you don't need to ...

2013年11月30日 · The sender object is actually the Control that initiated the event, you can cast it to the proper type to access all of its properties. You can use the Name as stated or as I sometimes do is to use the Tag Property. But in this case just …