Creating ASP.Net Controls

We can create ASP.Net controls in 2 ways:

• Mark Up Style   [preferred]
• Using Code / Object oriented style

Markup style syntax in ASP.Net:

<TagPrefix : TagName ID = "<controlname>" runat = "server" ......../>

Example: 

           <asp : Button ID = "button1" runat = "server" Text="Add"/>

           <Nit : Header ID = "Header1" runat = "server" />

All "asp" TagPrefix denotes they are pre-defined ASP.Net controls. Whereas, any other TagPrefix denotes they are User defined controls.

ID and runat attributes are mandatory.

Classical ASP doesn't have any controls to develop user interface.

Note: ID should be meaningfull and we must follow some conventions to name them like 

"btnAdd" for Button with Add as Text / Purpose.

"txtName" for TextBox for accepting Name.

"lstCource" ListBox for List of courses.

Placing Controls in Forms:

• <div> stands for division and it is a container where we can place other controls inside it. Once designed we can provide positioning option like centre, left, right etc., for <div>.
• The other method is to use table, where we can create rows/columns and place controls inside it. Positioning options can be given to table also. 
• Nested tables, div's can also be used for effective output.

Example:

Let's see one example to understand this.

before going to Example, we'll see two controls which we are going to use in our control.

ListBox / BulletedListBox: 

• ListBox is used to display multiple values.
• BulletedListBox is used to display multiple values like label for single values.

Now we'll example.

• Design a form as following.

 

• Coding

Under Button click:

        BLstRes.Items.Clear();
        BLstRes.Items.Add("User Information");
        BLstRes.Items.Add("Username :" + TxtName.Text);
        BLstRes.Items.Add("Email Id :" + TxtEmail.Text);
        if (LstCourse.SelectedIndex >= 0)
            BLstRes.Items.Add("Course :" + LstCourse.SelectedValue);
        else
            BLstRes.Items.Add("Course : Not Selected");

----------------------------------------------------------

** If you like this post please like our page in facebook

" Dot Net Support" 

Be a Fan

Posted in: ASP.Net Controls