Question

I’ve placed a static class TestClass in the App_Code folder. The class contains a static method TestMethod. From Default.aspx.cs via Button_Click method, I’m trying to invoke TestMethod. – test = TestClass.TestMethod().
This gives error: ‘TestClass’ is inaccessible due to its protection level.

It feels like the static class and the _Default class should be placed into a common namespace, but this would “exclude” the Default.aspx controls references.

What am I doing wrong?

Answer 1

You need to declare TestClass as public:

public static class TestClass
{
    public static SomeType TestMethod()
    {
    }
}

The default visibility is internal for types and private for members of a type definition. The App_Code folder gets compiled into its own assembly, different from the assembly that is created when compiling the code behinds. internal types cannot be shared between assemblies (that’s not 100% true but true in this case), hence why you are having this problem.