Cannot create an instance of the variable type 'Item' because it does not have the new() constraint

Question

I am trying to test a method - and getting an error:

Cannot create an instance of the variable type \'Item\' because it does not have the new() constr

Answer 1

You can't initialize Generic type object unless you mark it as implementing default constructor using new keyword:

public void CountTestHelper() where Item : IHasRect, new()
 {
    Rectangle rectangle = new Rectangle(0, 0, 100, 100); 
    SomeClass target = new SomeClass(rectangle);            
    Point p = new Point(10,10);
    Item i = new Item();    // constructor has to be parameterless!
    ...
 }

On the other hand, if you're trying to initialize an Item type object defined somewhere else in the application try using the namespace before it:

MyAppNamespace.Item i = new MyAppNamespace.Item(p, 10);