Causes and Countermeasures of Silverlight Update check failure outside the browser

When deploying Silverlight outside the browser, to make the Silverlight application deployed locallyProgramTo stay up to date, you usually need to add the update check function in the application. For specific implementation, see here.

In addition to the "using a new version of Silverlight that has not been installed by the user in the application" mentioned in the article, this may cause an update check failure. In addition, you may also encounter "unable to update the application, the certificate/signature status of the installed application and the updated alternative is different." . The security mechanism of Silverlight requires that the installed applications and update alternatives must have the same certificate/signature status. If the xap package is not signed, this requirement cannot be met. Therefore, if you are preparing to perform an update check during off-browser deployment of the Silverlight application in the formal environment (not available in the local development environment), you must sign the xap package.

If you can apply for a formal digital certificate, it is certainly the best solution. If you only apply it within the enterprise or within a small scope, you can also use a self-made certificate to sign the xap package. The steps are as follows:

1. Use makecert to create a self-made digital signature:

Makecert-r-pe-SS privatecertstore-n "cn = myname" mycert. Cer

If 'makecert 'is not an internal or external command... the cause is that the path where makecert is located is not added to the path of the system environment variable. This problem can be avoided by using Visual Studio command prompt.

2. Use the certificate generated in the previous step to sign the xap package:

Signtool sign/v/s privatecertstore/n myname MyApp. xap

Because the certificate is self-made and not added to the trusted area, "unable to verify publisher" still appears when the Silverlight application is installed locally ." But the Silverlight application signed by the preceding steps can already meet the requirement that the "installed application and update alternative must have the same certificate/signature status.