Question

In a project here, we have an Object ClassTest, which has many sub objects:

public class ClassTest
{
    public bool[] abTestAvailable = new bool[_TESTS];


    public ClassTest_FCT_Extern Test_FCT_Extern = API.Serializer.Load<ClassTest_FCT_Extern>(API.Workstation.strPath_Hardware + "FCT_Extern.xml");
    // ...

The idea was now, that Test_FCT_Extern sets abTestAvailable during initialization:

public class ClassTest_FCT_Extern
{
    public bool TestAvailable
    {
        get { return API.Test.abTestAvailable[(int)ClassTest.IndividualTest.FCT_Extern]; }
        set { API.Test.abTestAvailable[(int)ClassTest.IndividualTest.FCT_Extern] = value; }
    }

But this fails, because during the creation of the API.Test objects, the API.Test.Test_FCT_Extern is created. So, in this moment API.Test still does not exist and the Array abTestAvailable is not yet initialized.

I have found now a solution for our case, but maybe there are smarter ways to access parents parameters.

Answer 1

In our case, the solution was to make the array static:

public class ClassTest
{
    public static bool[] abTestAvailable = new bool[_TESTS];

The static array is initialized before the Objects are created

public class ClassTest_FCT_Extern
{

    public bool TestAvailable
    {
        get { return ClassTest.abTestAvailable[(int)ClassTest.IndividualTest.FCT_Extern]; }
        set { ClassTest.abTestAvailable[(int)ClassTest.IndividualTest.FCT_Extern] = value; }
    }

works fine, without exception.
Moral: make static if possible!