Preview a Windows Phone project
When you run a Windows Phone project in Blend for Visual Studio 2012, the project opens in the Windows Phone Emulator or in a Windows Phone device that is attached to your computer. You can also build your project without running it by using the Build Project (CTRL+SHIFT+B) command to build it.
Building your project as you work will help you identify errors as you work. Building your project also makes new user controls, custom controls that are defined in class files, and controls that are defined in .dll files available from the Assets panel.
You can then test your Windows Phone project by running it using the Run Project command (F5 or CTRL+F5).
To build a Windows Phone project
Make sure that you have the correct project open in Blend, and then, on the Project menu, click Build Project.
You can also use the commands Rebuild Project and Clean Project on the Project menu as part of your testing and build efforts. Rebuild Project rebuilds everything, including components that are built from files that have not been changed. Clean Project deletes all intermediate files that are generated by the build, but will not rebuild the project.
In the Results panel, review the build process for any errors that may have been returned. If you encounter an error, the build will be unsuccessful, and you will have to repair the error before you can successfully build the project.
To run a Windows Phone project
With a project open in Blend, click Run Project on the Project menu, or press F5.
If the build succeeded, your project will automatically open in a Windows Phone Emulator or a Windows Phone device, if you have one attached to your computer.
To change whether your application opens in the Windows Phone Emulator or a Windows Phone device, see Modify the Device panel settings.
If the build did not succeed, the Errors tab of the Results panel will list the errors that occurred. You have to repair the errors before you can successfully run the project.