Life Cycle of ASP.NET
Life Cycle of ASP.NET
Page Life Cycle Events
- Page_Init: The server controls are loaded and initialized from the Web form's view state. it is basically used for initialized the object and control
- Page_Load:The server controls are loaded in the page object. View state information is available at this point, so this is where you put code to change control settings or display text on the page.
- Page_PreRender: The application is about to render the page object.
- Page_Unload: The page is unloaded from memory.
- Page_Disposed: The page object is released from memory. This is the last event in the life of a page object.
- Page_Error: An unhandled exception occurs.
- Page_AbortTransaction: A transaction is aborted.
- Page_CommitTransaction: A transaction is accepted.
- Page_DataBinding: A server control on the page binds to a data source.
Control in ASP.NET
-
HTML Controls - Traditional HTML tags
-
Web Server Controls - New ASP.NET tags
-
Validation Server Controls - For input validation
HTML Server Controls
HTML server controls are HTML tags understood by the server.
HTML elements in ASP.NET files are, by default, treated as text. To make these elements programmable, add a runat="server" attribute to the HTML element. This attribute indicates that the element should be treated as a server control. The id attribute is added to identify the server control. The id reference can be used to manipulate the server control at run time.
Note: All HTML server controls must be within a <form> tag with the runat="server" attribute. The runat="server" attribute indicates that the form should be processed on the server. It also indicates that the enclosed controls can be accessed by server scripts.
DESIGN OF HTML CONTROL
<script language="javascript" type="text/javascript">
function Submit1_onclick() {
alert("click me");
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<input id="Text1" type="text" value="anil" />
<input id="Submit1" type="submit" value="submit"
|
Web Server Controls
- Web server controls are special ASP.NET tags understood by the server.
- Like HTML server controls, Web server controls are also created on the server and they require a runat="server" attribute to work.
- However, Web server controls do not necessarily map to any existing HTML elements and they may represent more complex elements.
The syntax for creating a Web server control is:
| <asp:control_name id="some_id" runat="server" /> |
DESIGN OF WEB SERVER CONTROL
.ASPX CODE
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div style="width: 246px; background-color: #66FFFF;">
Name
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<br />
<asp:TextBox ID="TextBox2"
runat="server" ></asp:TextBox>
<br />
<br />
<asp:Button ID="Button1" runat="server" onclick="Button1_Click"
Text="click me" />
<br />
<br />
</div>
</form>
</body>
</html>
|
.CS CODE
protected void Button1_Click(object sender, EventArgs e)
{
TextBox1.Text = "wiliam";
TextBox2.Text = "hello world";
}
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Validation Server Controls
DESIGN OF VALIDATION SERVER CONTROL
Validation server controls are used to validate user-input. If the user-input does not pass validation, it will display an error message to the user.
.ASPX CODE
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div style="width: 414px; background-color: #66FFFF;">
Name
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server"
ControlToValidate="TextBox1" ErrorMessage="Blank are not allowed"
SetFocusOnError="True"></asp:RequiredFieldValidator>
<br />
Address
<asp:TextBox ID="TextBox2"
runat="server" ontextchanged="TextBox2_TextChanged"></asp:TextBox>
<br />
<br />
<asp:Button ID="Button1" runat="server" onclick="Button1_Click"
Text="click me" />
<br />
<br />
</div>
</form>
</body>
</html>
|
CS CODE
protected void Button1_Click(object sender, EventArgs e)
{
TextBox1.Text = "123";
TextBox2.Text = "hello world";
Response.Write("hi display textbox 1 value"+TextBox1.Text);
}
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