Click Once

-

ClickOnce enables the user to install and run a Windows application (MEX/FleetMEX) by clicking a link in a web page. The core principle of ClickOnce is to bring the ease of deployment of web applications to the Windows user. In addition, ClickOnce aims to solve three other problems with conventional deployment models: the difficulty in updating a deployed application, the impact of an application to the user’s computer, and the need for administrator permissions to install applications.

  • Difficulties in updating applications. With Microsoft Windows Installer deployment, whenever an application (MEX/FleetMEX client) is updated, the user must reinstall the entire application; with ClickOnce deployment, you can provide updates automatically. Only those portions of the application that have changed are downloaded, then the full, updated application is reinstalled from a new side-by-side folder.
  • Impact to the user’s computer. With Windows Installer deployment, applications often rely on shared components, with the potential for versioning conflicts; with ClickOnce deployment, each application is self-contained and cannot interfere with other applications.
  • Security permissions. Windows Installer deployment requires administrative permissions and allows only limited user installation; ClickOnce deployment allows non-administrative users to install and grants only those Code Access Security permissions necessary for the application.

You can publish a ClickOnce application in three different ways: from a Web page, from a network file share, or from media such as a CD-ROM. A ClickOnce application can be installed on an end user’s computer and run locally even when the computer is offline, or it can be run in an online-only mode without permanently installing anything on the end user’s computer.

ClickOnce-deployed applications are considered ‘low impact’, in that they are installed per-user, not per-machine. No administrator privileges are required to install one of these applications. Each ClickOnce application is isolated from the other. This means one ClickOnce application is not able to ‘break’ another.

ClickOnce employs CAS (Code Access Security) to ensure that system functions cannot be called by a ClickOnce application from the web, ensuring the security of data and the client system in general.

The ClickOnce deployment technology is integrated into the Visual Studio 2005 project system and is also natively supported by MSBuild technology.
After it is deployed to the deployment location, end users can download and install the application by clicking an icon representing the deployment manifest file on a Web page or in a folder. In most cases, the end user is presented with a simple dialog box asking the user to confirm installation, after which installation proceeds and the application is launched without further intervention. In cases where the application requires elevated permissions, the dialog box also asks the user to grant permission before the installation can continue.

The application is added to the user’s Start menu and to the Add/Remove Programs group in the Control Panel. Unlike other deployment technologies, nothing is added to the Program Files folder, the registry, or the desktop, and no administrative rights are required for installation.

In addition to the deployment location, the deployment manifest also contains an update location (a Web page or network file share) where the application checks for updated versions. ClickOnce Publish properties are used to specify when and how often the application should check for updates. Update behaviour can be specified in the deployment manifest, or it can be presented as user choices in the application’s user interface by means of the ClickOnce APIs (Application Programming Interfaces). In addition, Publish properties can be employed to make updates mandatory or to roll back to an earlier version.

ClickOnce versus the current client install – Comparison Table

The following table compares the features of ClickOnce deployment with the current Client Installer deployment:

Feature

ClickOnce

Current Client Install
Automatic update Yes Yes
Post-installation rollback Yes No
Update from Web Yes No
Does not affect shared components or other applications Yes No
Security permissions granted Grants only permissions necessary for the application (more safe) Grants Full Trust by default (less safe)
Security permissions required Internet or Intranet Zone (Full Trust for CD-ROM installation) Administrator
Installation-time user interface Single prompt Multipart Wizard
Installation of assemblies on demand Yes No
Installation of drivers No Yes (with custom actions)
Add application to Start menu Yes Yes
Add application to Favourites menu No Yes
Application installation location ClickOnce application cache Program Files folder


Comments

Post a Comment

Please register before posting your comment here !!

Popular posts from this blog

Simple and Versatile Navigation – Tree View

-
Image
The system can present a so-called ‘tree view’ of the Assets Register. The hierarchy of Client, Location, Assets and Parts, etc is presented on screen, enabling you to view all the interrelationships and navigate your way around your enterprise’s entire asset population. The tree view is the most convenient and intuitive way in which to explore and scrutinise the enterprise’s asset population, as well as its organisational structure. And it’s interactive. You also have quick access to the compendium of information held for each location, system and equipment item. You can drill-down to find the information you need; click on any item to view its full details. For example, you can view the asset list at each location, a single asset’s assembly hierarchy down to part level, find out where any particular part is used, who supplies it, the technical specification, see a picture of it – and study any other information filed against it. You can expand or collapse branches to drill down to
Read more

Creating Online Portfolio Gallery Tutorials

-
Image
Times really have changed! Only a few years ago it was par for the course to travel across town (or the country) lugging a heavy portfolio case full of treasured works, or mailing them to a faceless stranger. There was the fear of damage, or worse still, hearing the words, "Can you just leave it here with us for a few days," not knowing what will happen to them as soon as we turn our backs. I have a hunch that the printed portfolio will be with us well into the future. However there is a growing trend to put a portfolio on the web. This has obvious advantages; Your site is up 24/7, it's cheap, can be viewed by anyone around the world and the potential audience is huge. Since launching PhotoshopCAFE.com almost 5 years ago, over 3 million people from around the world have viewed my portfolio, this would be impossible without the web. Photoshop makes it very easy to build an online portfolio. I will show you how in just a few steps and we can do it all from the File Br
Read more

Easter Eggs on Windows NT

-
Volcano 1. Right click on the desktop and select Properties. Or open Control Panel from the Start button/Settings menu and select Display. 2. From the Display Properties, select Screen Saver. 3. Select 3D Text (OpenGL) as your screen saver type. 4. Click on the Settings button to configure the screen saver. 5. Change the text that the screen saver will display to "Not Evil". 6. Click OK to save the changes. Click the test button or wait until the screen saver kicks in the next time. 7. This will show the names of all the members of the Windows NT developer team. 8. You can also try the changing the text to "Volcano". 9. This will display the names of a bunch of volcanoes all over the world. Pipes Screensaver 1. Open Control Panel 2. Open Desktop 3. Select 3D Pipes (OpenGL) as the screen saver 4. Click Setup, and set the joint style to mixed. 5. When the screen saver comes on - look closely. Every once in a while, a 'teapot joint' will appear.
Read more