Discuss C# - subscribe to event and casting in the General Programming Help forum on Dev Articles. as in "we know the sender is a Text Box, so we cast the sender object to tha". I think Java language has this things as well because it is OOP concept. answer to ur first question Event is raised whenever the specified condition is met. now when event is raised, there are behind scene actions which for a lot of time can be ignored. This is very brief and simple description for detailed description, I really recommend Wrox's Professional ASP. Which has a whole chapter devoted to advanced Event handling. Casting just means changing between types (classes).C# - subscribe to event and casting General Programming Help forum discussing Perl, Python, Scripting and/or any languages that do not fit into any of the categories above. What the event does is that notfies its subscribers through delgates. "we know the sender is a Text Box, so we cast the sender object to that"This sentence just means because we know that the class that raised the event (which is sent to the handler as object class called sender) is textbox object, we can jsut cast it to textbox with out raising any error caused when you try to cast an object to an incompatible object such as when you try to convert sqlconnection object to sqlcommand object. I read the help from MSDN, and do not understand it quite well. Yes, this might silly question , but I still do not understand when you just put object sender; you are creating an instance of object class called 'object' and that instance is called sender object class is what EVERY class in .This means that the value for the letter a is not the same as the letter A.
Text boxes should be used when you want users to enter text that you have no knowledge of at design time (for example, the user's name).
An example of this is when a user clicks a Help button.
, on the other hand, receives the character corresponding to a keyboard key.
This means that you must do the checking elsewhere.
In this example, there are a number of criteria to enforce to ensure that the values are correct: .