SPDisposeCheck is a tool to help you to check your assemblies that use the SharePoint API so that you can build better code. It provides assistance in correctly disposing of certain SharePoint objects to help you follow published best practice. This tool may not show all memory leaks in your code. Further investigation is advised if you continue to experience issues.
You can download from CodePlex here.
here is the example show you how to dispose the patterns.
How to use it
1. Install SPDisposeCheck.msi on your development server.
2. Open a command window.
3. Type following command:
“c:\Program Files\Microsoft\SharePoint Dispose Check\SPDisposeCheck.exe” “.dll”