user control

Question

what is the use of user control ?how to use the user control in asp .net?

Satyapriya Nayak · Answer

Hi Rajkamal, To create an instance of a user control programmatically In the user control, be sure that the @ Control directive contains a ClassName attribute that assigns a class to the user control. The following example sets the ClassName attribute to strongly type a user control. Copy In the page where you want to work with the user control, create a reference to the user control with the @ Reference directive. When you create the user control programmatically, the strong type for your user control is available to the ASP.NET Web page only after you have created a reference to it. For example, the following code creates a reference to a user control created in the MyUserControl.ascx file. Copy Create an instance variable for the user control, using the control's class name. The class will be part of the ASP namespace. For example, if you want to create an instance of the user control declared as class Spinner, you use syntax such as the following: VB Copy Protected Spinner1 As ASP.Spinner C# Copy Protected ASP.Spinner Spinner1; Create an instance of the user control in code by calling the LoadControl method. Assign property values as necessary, and then add the control to the ControlCollection collection of a container on the page, such as a PlaceHolder control. The following example shows an ASP.NET Web page that loads a user control programmatically. The page includes an @ Reference directive to specify the control's file. The LoadControl method reads the file and instantiates it as a control that can be added to the page. C# VB Copy private ASP.Spinner Spinner1 protected void Page_Load(object sender, EventArgs e) { Spinner1 = (ASP.Spinner)LoadControl("~/Controls/Spinner.ascx"); } protected void Button1_Click(object sender, EventArgs e) { PlaceHolder1.Controls.Add(Spinner1); } Load User Control Programmatically Also Please refer the below links, http://msdn.microsoft.com/en-us/library/c0az2h86.aspx, http://www.c-sharpcorner.com/uploadfile/jayendra/how-to-create-user-control-in-Asp-Net/ Thanks

Shivanand Arur · Answer

A User Control is basically a Control which is created by the User as the name itself specifies... It is basically an file with a .ascx extension. (eg: LoginControl.ascx) It also has its own code page (eg: LoginControl.ascx.cs) where you can add your logic. To add a User Control you can simply right click on the Solution and select " Add" and select "New Item ". In the Panel which opens, you select the " Web User Control". You give a Name to it and click on " Add " button. A new User Control page with ( . ascx ) extension will be added to your solution. For Example - I have a Login User Control which has to code in the .ascx file like this.... Login Display="None" ValidationGroup="AcceptLoginDetails" ErrorMessage="Email ID is required." CssClass="errorLabel"> Display="None" ControlToValidate="txtLoginID" ValidationGroup="AcceptLoginDetails" CssClass="errorLabel" ValidationExpression="^([a-zA-Z0-9_\-\.]+)@(($$[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})($$?)$"> onkeydown="return myError(document.getElementById('LoginCtrl_lblCapsError'),event)" onkeypress="return getCAPSLOCKError(document.getElementById('LoginCtrl_lblCapsError'),event);"> Display="None" ValidationGroup="AcceptLoginDetails" ErrorMessage="Password is required." CssClass="errorLabel"> OnClick="btnSignIn_Click" ToolTip="Click here to login into SmartSociety" OnClientClick="javascript:return fnLogin();" /> CssClass="forgotPasswordLink" OnClientClick="javascript:return HidePopup('forgot password');"> --%> After creating the User Control, you have to register on the page where you want to use it. Info - Here " LoginControl " is the tag name of the LoginControl and you have to give a Prefix to that control as I have given above "login" The Prefix is just the same which we have in our Server Controls as " asp: " and the tag-name is the same as "asp: Panel ". After registering the Control, you can simply drag and drop the control as I have done it inside a Panel -