Inheritance and Generics? Factory class?

Cuong Me

6y638Learn iOS Programming

I have a grid class (will remove most of the properties to keep it short)

public class WinGrid

{

public List Rows

{

...

}

public class WinGridRow

{

public WinGridRow(WinGrid parent)

{

// Many properties and methods

}

Basically I want to inherit the Grid class but the Rows property returns a list of GridRow. The GridRow class does what I what to do but I want to inherit it and add more specific methods and properties. I what to know the best approach and to go about it. Generics? Factory?

Any help will be appreciated.

Thanks

6 Replies

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Guest User6y ago
Sounds like something is in a different scope. It's hard to tell without being able to see the code.
Cuong Me6y ago
public List<WinGridRow> Rows
{
... new WinGridRow(this,......).ToList()
}
becomes

public List<T> Rows
{
... new T(this,......).ToList()
}

'this' (WinGrid) is now WinGrid. How do I fix the error?
Cuong Me6y ago
That's what I did but get error:

The type or namespace name 'T' could not be found (are you missing a using directive or an assembly reference?)

Do I need to change the WinGrid constructor?

public class WinGrid where T : WinGridRow
{
public WinGrid(..., ...)
public List Rows
{
...
}
}
Guest User6y ago
Everyting that was WinGridRow should now be T
Cuong Me6y ago
The exisiting Rows property in WinGrid looks like

public List<WinGridRow> Rows
{
... new WinGridRow(this,......).ToList()
}

I've replaced public List<WinGridRow> Rows -> public List<T> Rows
What's the syntax for new WinGridRow?

Sorry, still quite new with generics :(
Guest User6y ago
I'd suggest generics. That way you pass in the class you want to use. I'd use WinGridRow as the base class, so you can be sure that you can only pass descendant classes of WinGridRow.

public class WinGrid where T : WinGridRow
{

public List Rows
{
...
}
}

If the WinGrid has to use specific properties of one of your descendant classes, you may have to make some methods virtual, so you can override them where needed.