I have a custom static library i´m trying to use it with Windows Phone Runtime.
I could not add in to the Windows Runtime.
Is there a way to use Static Libraries in Windows Runtime "Windows Phone 8"
You can add a static lib to a Runtime Component the same way you add a static library in a Console app in Visual C++.
Taken from this MSDN page...
To use the functionality from the static library in the app
After you create a console app, an empty program is created for you. The name for the source file is the same as the name that you chose earlier. In this example, it's named MyExecRefsLib.cpp.
Before you can use the math routines in the static library, you must reference it.
To do this, open the shortcut menu for the MyExecRefsLib project in Solution Explorer, and then choose References. In the MyExecRefsLib Property Pages dialog box, expand the Common Properties node, select Framework and References, and then choose the Add New Reference button. For more information about the References dialog box, see Framework and References, Common Properties, Property Pages Dialog Box.
The Add Reference dialog box lists the libraries that you can reference. The Projects tab lists the projects in the current solution and any libraries that they contain. On the Projects tab, select the MathFuncsLib check box, and then choose the OK button.
To reference the MathFuncsLib.h header file, you must modify the included directories path. In the Property Pages dialog box for MyExecRefsLib, expand the Configuration Properties node, expand the C/C++ node, and then select General. Next to Additional Include Directories, specify the path of the MathFuncsLib directory or browse for it.
To browse for the directory path, open the property value drop-down list, and then choose Edit. In the Additional Include Directories dialog box, in the text box, select a blank line and then choose the ellipsis button (…) at the end of the line. In the Select Directory dialog box, select the MathFuncsLib directory and then choose Select Folder button to save your selection and close the dialog box. In the Additional Include Directories dialog box, choose the OK button, and then in the Property Pages dialog box, choose the OK button to save your changes to the project.