"PragmaNoCache" is an element of the HTTP header that specifies that the browser should not cache the image locally, but re-fetch it from the server whenever the page is refreshed. If your chart is updated frequently, you should set this property to True to ensure that the browser is always displaying the latest version of the chart. You should also set this property to True if your application automatically forces page refreshes on the browser.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2