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 ...

@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 …

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.

@Sean87 This answer addresses the problem of not being able to access the Data field but a better long term approach is to follow Hans's comment and override OnClick or possibly introduce custom events to make things a touch more typesafe - you currently rely on wiring up the customhandler (which is just a standard handler signature) to the right buttons.

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).

The Reply-To header is added by the sender (or the sender's software). It is where all human replies should be addressed too. Basically, when the user clicks "reply", the Reply-To value should be the value used as the recipient of the newly composed email. The Reply-To value should not be used by any server. It is meant for client-side (MUA ...

2015年12月17日 · Manually cast the sender to the type of your custom control, and then use it to delete or disable etc. Eg, something like this: private void myCustomControl_Click(object sender, EventArgs e) { ((MyCustomControl)sender).DoWhatever(); } The 'sender' is just the object that was actioned (eg clicked).

2008年9月23日 · Most people need to change two values when trying to correctly forge the from address on an email. First is the from address and the second is the orig-to address.

2017年3月21日 · The sender and e arguments are the standard signature of event handlers. Sender is the object that raised the event and e contains the data of the event. All events in .NET contain such arguments. EventArgs is the base class of all event arguments and doesn't say much about the event.

Private Sub Button_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click, Button2.Click Dim s As String If sender Is Button1 Then s = "button1" ElseIf sender Is Button2 Then s = "button2" End If MessageBox.Show("You pressed: " + …