In this article, we will learn different techniques that are used for page navigation in ASP.net.
Page navigation is a navigational technique used for moving from one webform to another in asp.net.
There are several ways for page navigation and they are outlined as follows;
1. Server.Transfer
2. Response.Redirect
3. Cross-Page Postback
4. Server.Execute
5. Window.Open
6. Hyperlink control
Server.Transfer is used to navigate to other pages or sites running on the same web server.
Server.Transfer(path)
Where path refers to the location of the file to which control should be transfered
1. It does not navigate to sites/pages that are outside the web server
2. Its URL remains unchanged in the address bar
3. The form variables from original request page are retained.
4. It is faster than Response.Redirect as the redirection happens on the server in one request/response cycle.
When Server.Execute method is used, the path to the destination page is passed to the Server.Execute Method as a parameter and the control moves to this new page.
However, execution of code happens on the new page and once code execution on the destination page is over, the control returns to the initial page, just after where it was called.
Server.Execute(path)
Where path refers to the location of the requested page
1. It does not navigate to sites/pages that are outside the web server
2. Its URL remains unchanged in the address bar
3. The form variables from original request page are retained.
4. It is faster than Response.Redirect as the redirection happens on the server in one request/response cycle.
If you noticed, Server.Transfer and Server.Execute url shares the same characteristics. The only difference is;
The difference between Server.Transfer and Server.Execute is;
Server.Transfer will stop the execution of the current page and proceed imnediately to execution of the new requested page.
While;
Server.Execute process the second webform without terminating the first Web form. However, after the complete execution of the first page the control returns to second page.
The Response.Redirect() method is used to redirect a user from one page to another and also letting the user know that you have been redirected from your current page to another.
It has the following syntax;
Response.Redirect(path)
Where path refers to the destination file that is requested by the client.
1. When the user clicks a redirect button, the webserver receives, a request for redirection.
2. The server then sends a response header to the client.
3. Then the client browser automatically issues a new GET request to the web server.
4. The web server will then serve the new page.
Note: Response.Redirect causes 2 request/response cycles.
By default, when you as a user click a button on a asp.net web form where Response.Redirect is not used on the codebehind, or PostBackUrl attribute value is not specified, the webform will postback to itself.
So If you as a developer want the user to be posted to another webform on a button clcik, you have to set the PostBackUrl of the button to the page that you want to post to.
If Page.IsPostBack Then
'Code to execute
Else
'Code to execute
End If
1. Page.IsCrossPagePostBack property is used to indicate whether the page is involved in a cross-page postback
2. It sends the post to another page if PostBackUrl is specified
The Hyperlink control displays a HTML link to an address, which opens in the default browser for the computer. Links are not supported for protocols other than HTML.
The page you want to navigate to is specified using NavigateURL property. Using hyperlink, you can navigate to another page within same or outside the application or even to external website. The hyperlink control is rendered as an HTML anchor
<![CDATA[<a>]]> tag. The Hyperlink control does not expose any server side events, so when the user clicks on a hyperlink there is no server side event to intercept the click.
<asp:HyperLink id="hyperlink1" NavigateUrl="#" Text="" runrunaterver"/>
1. NavigateURL property can be hardcoded
2. NavigateURL can also be changed dynamically from codebehind
window.open(URL,name,specs,replace)
1. The open() method opens a new browser window.
2.The Close() method is needed to close the windows
3. The open() is supported in all major browsers like chrome,safari,opera,IE
- URL(Optional)-: Specifies the URL of the page to open. If no URL is specified, a new window with about:blank is opened
- name(Optional)-: Specifies the target attribute or the name of the window. The following values are supported:
_blank: URL is loaded into a new window. This is default
_parent: URL is loaded into the parent frame
_self: URL replaces the current page
_top: URL replaces any framesets that may be loaded
name: The name of the window (Note: the name does not specify the title of the new window)
- specs (Optional)-: A comma-separated list of items. The following values are supported:
channelmode=yes|no|1|0 Whether or not to display the window in theater mode. Default is no. IE only
directories=yes|no|1|0 Obsolete. Whether or not to add directory buttons. Default is yes. IE only
fullscreen=yes|no|1|0 Whether or not to display the browser in full-screen mode. Default is no. A window in full-screen mode must also be in theater mode. IE only
height=pixels. The height of the window. Minimum value is 100
left=pixels. The left position of the window. Negative values not allowed
location=yes|no|1|0 Whether or not to display the address field. Opera only
menubar=yes|no|1|0 Whether or not to display the menu bar
resizable=yes|no|1|0 Whether or not the window is resizable. IE only
scrollbars=yes|no|1|0 Whether or not to display scroll bars. IE, Firefox & Opera only
status=yes|no|1|0 Whether or not to add a status bar
titlebar=yes|no|1|0 Whether or not to display the title bar. Ignored unless the calling application is an HTML Application or a trusted dialog box
toolbar=yes|no|1|0 Whether or not to display the browser toolbar. IE and Firefox only
top=pixels The top position of the window. Negative values not allowed
width=pixels The width of the window. Min. value is 100
- replace (Optional)-: Specifies whether the URL creates a new entry or replaces the current entry in the history list. The following values are supported:
true – URL replaces the current document in the history list
false – URL creates a new entry in the history list