ClickOnce

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ClickOnce is a technology from Microsoft that enables Windows applications to be started over the Internet with just one click. Such applications are also known as smart clients . It supports applications developed with Windows Forms or Windows Presentation Foundation ; other applications can be updated using the so-called Updater Application Block . ClickOnce is similar to Java Web Start for the Java platform or Zero Install for Linux .

description

ClickOnce gives the user the ability to install and run programs just by clicking a link on a web page. The core principle of ClickOnce is to bring the simplicity of web applications to Windows users. In addition, ClickOnce aims at solving three other problems of conventional models of software distribution : the difficulty of updating a deployed program , the side effects of a program on the user's computer, and the need for elevated (administrative) user rights to install programs.

Programs distributed via ClickOnce are classified as "little influencing" because they are only installed for the individual user, not for the entire computer (ClickOnce cache). No administrator rights are required to install. Each ClickOnce program is separate from the other. This means that one ClickOnce application cannot change or destroy another.

ClickOnce uses CAS ( Code Access Security ) to ensure that system functions cannot be accessed by a ClickOnce program from the Internet, which guarantees the security of the data and the system in general.

Programs

The ClickOnce model supports two types of applications: installed programs (similar to conventional Windows applications with Windows Start menu integration) and online applications (browser hosted programs that are not installed, only run and cached are). ClickOnce programs can be distributed from a website, network share, or even from a file location.

The ClickOnce distribution technology is integrated into the Visual Studio 2005/2008 project system and is natively supported by the MSBuild technology.

After ClickOnce only worked with Internet Explorer for a long time, Service Pack 1 for .NET Framework 3.5 also supports Mozilla Firefox . When installing the service pack, an extension ( add-on ) called “Microsoft .NET Framework Assistant” is installed in Firefox, which in the first versions could only be uninstalled by intervening in the registry . The user agent identification is optionally supplemented with the information about the installed .NET version so that the server can react to its existence - as with Internet Explorer.

Manifestos

A ClickOnce application by two XML - manifestos controls: a deployment manifest and a program manifesto. The deployment manifest file describes the distribution model: the current version, update behavior, identity of the publisher, and a digital signature. This manifesto should be used by the administrators who regulate the distribution. The program manifest - an .exe.manifest file - describes the assemblies of the program, referenced libraries, and lists permissions that are required by the program. This file is intended to be used by the developer of the program. To start a ClickOnce application, the user clicks on the deployment manifest file.

Updates

ClickOnce programs are self-updating; you can automatically check for the availability of a newer version at startup and replace any updated files. ClickOnce also offers some update options for programs to be installed . For example, programs can be configured so that they check for available updates as soon as they are started or after they are started. ClickOnce also offers a programming interface to adapt the update behavior to personal needs. There is also support for required or mandatory updates, managing ongoing updates, and ensuring that the entire user base can be upgraded to a new version in no time.

See also

literature

  • Sayed Y. Hashimi, Sayed Ibrahim Hashimi: Deploying .NET Applications: Learning MSBuild and ClickOnce , Springer 2008, ISBN 978-1590596524

Individual evidence

  1. ↑ Updater Application Block version 2.0
  2. ↑ http://msdn.microsoft.com/de-de/library/cc716877.aspx
  3. ↑ http://www.it-visions.de/glossar/alle/692/Click-Once-Deployment.aspx
  4. ↑ http://www.apress.com/9781590596524

Web links