ASP.NET Raising Events
In the ASP.NET applications that I write, the ASP.NET User Controls (System.Web.UI.UserControl) contain the UI controls that interact direcly with the user. The User Controls do not retrieve data but rather process user events - raise events.
The ASPX pages (System.Web.UI.Page) rarely contain UI controls but contain the User Controls. They are responsible for retrieving application data and sending the data to the User Controls.
Giving the user controls sole responsibility of user interaction helps me to keep my code and applications organized.
In the example below, the ASPX page contains a button that submits a calculation to the code behind classes.
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ASPX listens & initializes User Control
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In PageLoad method I add:
//initialize user control UCCalculate.Initialize(); //register event listener with user control UCCalculate.ClickedCalculateButton += new EventHandler(EventListener); Somewhere in the ASPX page add the method that is called when the user control raises an event.
public void EventListener(object sender, EventArgs e) { if (sender is Button) { //process button action here } } //////////////////////////////////////////////////////
User Control raises events
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Declarations section:
public event EventHandler ClickedCalculateButton; on click of button call Click_Calculate method.
<asp:Button id="btnSubmit" runat="server" Text="Calculate" OnClick="Click_Calculate" CommandName="Calculate" CssClass="button"/>Somewhere in the User Control class:
public void Click_Calculate(object sender, EventArgs e) { //check if listener was registered if (ClickedCalculateButton != null) { //raise event (goes to ASPX EventListener method mentioned above) to process button action ClickedCalculateButton(Btn_clicked, e); } }I finally documented my madness. I hope this helps you, too. How do you handle events in your ASP.NET application?
Signing Off,
Vivian
ViSO Tech
Categories: Code Snippets, .NET 3.5, Web Programming, Concepts, .NET 2.0
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