[转]Prevent opening multiple windows in ASP.NET

本文转自：http://code.msdn.microsoft.com/CSASPNETPreventMultipleWind-b1dd2bd6

CSASPNETPreventMultipleWindows Overview

Use:

The project illustrates how to detect and prevent multiple windows or
tab usage in Web Applications.

Demo the Sample.

Please follow these demonstration steps below.

Step 1: Open the CSASPNETPreventMultipleWindows.sln.

Step 2: Expand the CSASPNETPreventMultipleWindows web application and press
Ctrl + F5 to show the Default.aspx.

Step 3: We will see two links on the page. First, you can Left click one
of them jump to correct link(Like Nextlink.aspx and Nextlink2.aspx).

Step 4: Then, you can right click these links and choose Open In New Tab
or Open In New Window,and you will find the link not available.

Step 5: you can even copy the right url and Paste it in the browser address bar for
test.but you can not achieve your goal.

Step 6: Validation finished.

Code Logical:

Step 1. Create a C# "ASP.NET Empty Web Application" in Visual Studio 2010 or
Visual Web Developer 2010. Name it as "CSASPNETPreventMultipleWindows".

Step 2. Add one folder, "UserControls".Add two User Controls in this folder,
"DefaultPage.ascx","NextPage.ascx".

Step 3. Add five web forms in the root directory,"Default.aspx","InvalidPage.aspx"
,"Main.aspx","NextLink.aspx","NextLink2.aspx".

Step 4. Move DefaultPage.ascx user control on Default.aspx file and move
NextPage.ascx user control on all other files extension name are ".aspx".
In Defalut.aspx.cs page, we have a method generate unique random number:
[code]
public string GetWindowName()
{
string WindowName = Guid.NewGuid().ToString().Replace("-", "");
Session["WindowName"] = WindowName;
return WindowName;
}

And window.name will recieve this unique string,we use window.name to prevent
mutiple windows and tabs.

//set window.name property
window.open("Main.aspx", "<%=GetWindowName() %>");

//If this window name not equal to sessions,will be goto InvalidPage
if (window.name != "<%=GetWindowName()%>") {
window.name = "InvalidPage";
window.open("InvalidPage.aspx","_self");
}

Step 5. Write the codes like the sample.you can get more details from comments in
the sample file.

Step 6. Build the application and you can debug it.

References:

MSDN: User control http://msdn.microsoft.com/en-us/library/fb3w5b53.aspx [/code]