What control is the event handler?

Event Handling Using Controls All ASP.NET controls are implemented as classes, and they have events which are fired when a user performs a certain action on them. For example, when a user clicks a button the ‘Click’ event is generated.

Which event will occur whenever the user control load?

The Load event occurs when the handle for the UserControl is created. In some circumstances, this can cause the Load event to occur more than one time. For example, the Load event occurs when the UserControl is loaded, and again if the handle is recreated.

How do I make an event in the UserControl and have it handled in the main form?

You need to create an event handler for the user control that is raised when an event from within the user control is fired. This will allow you to bubble the event up the chain so you can handle the event from the form.

How do you make the events raised by child controls in a user control available to the host page?

By default, events raised by child controls in a user control are not available to the host page. However, you can define events for your user control and raise them so that the host page is notified of the event. You do this in the same way that you define events for any class.

What is the event handler that occurs at the beginning of each request to the server?

Application_BeginRequest: This occurs at the beginning of each request to the server.

How do you link two events to a single event handler in Windows Forms?

Select the control to which you want to connect an event handler. Click the name of the event that you want to handle. In the value section next to the event name, click the drop-down button to display a list of existing event handlers that match the method signature of the event you want to handle.

What is event bubbling in C#?

Simply calling a parent control’s event from a child control is called Event bubbling. Handling child controls events through parent control in data bind controls known as event bubbling. Server controls like Datagrid, DataList, and Repeater can have other child controls inside them.

How do you pass EventArgs?

Passing Parameters to Events – C#

1. public Form1()
2. {
3. InitializeComponent();
4. button1.Click += new EventHandler(button_Click);
5. button2.Click += new EventHandler(button_Click);
6. }
7. void button_Click(object sender, EventArgs e)
8. {

What is an event ARG?

EventArgs e is a parameter called e that contains the event data, see the EventArgs MSDN page for more information. Object Sender is a parameter called Sender that contains a reference to the control/object that raised the event. Event Arg Class: http://msdn.microsoft.com/en-us/library/system.eventargs.aspx.

What happens if an event occurs and there is no event handler to respond to the event?

TF: if an event occurs and there is not event handler to respond to that event, the event ins ignored.

Are event handlers delegates?

The EventHandler delegate is a predefined delegate that specifically represents an event handler method for an event that does not generate data. If your event does generate data, you must use the generic EventHandler delegate class.

Can event handler return a value?

Firing an event is a one-way signal. By default most event handlers return void , because single event may have several subscribers, and return value could become ambiguous. However, it is possible for handlers to return values.

What is user control how it is created?

You create ASP.NET user controls in much the same way that you design ASP.NET Web pages. You can use the same HTML elements and controls on a user control that you do on a standard ASP.NET page. However, the user control does not have html, body, and form elements; and the file name extension must be .

What is an event handler How is it designed?

About Event Handler Events are declared using delegates. Events are the higher level of Encapsulation over delegate. A delegate that exists in support of an event is called as an event handler. Event handlers are methods in an object that are executed in response to some events occurring in the application.

How do I return an event handler?

A second way for an event handler method to return a value back to the sender is for the delegate that the event is based on to include just that — a return value. Instead of being declared to return void, the delegate on which the event is based can be defined to return a type such as bool or int.

What is meant by event handling in Java?

Event Handling is the mechanism that controls the event and decides what should happen if an event occurs. This mechanism have the code which is known as event handler that is executed when an event occurs. Java Uses the Delegation Event Model to handle the events.

How does an event handler work?

Each key node has a handler that receives key events when the key has focus. The handler responds to the key-pressed and key-released events for the Enter key by changing the color of the key on the screen. The event is then consumed so that the keyboard node, which is the parent node, does not receive the event.