Delphi: generics and TObjectList
I've created a class like
TMyClass = class(TObject)
private
FList1: TObjectList<List1>;
FList2: TObjectList<List2>;
public
end;
Now, I want a method FillArray(Content);
, which preferably should be imp开发者_开发知识库lemented once, i.e. no overload. I believe this is possible using generics, but I'm too inexperienced with these beasts to actually implement it. Do anyone have a clue? Thanks in advance!
The following I believe will only work in Delphi 2010. As it depends on the declaration of TArray<T> in the system unit, that looks like this:
TArray<T> = array of T;
Here is unit I have developed to help with TArray to List conversions
unit ListTools;
interface
uses Generics.Collections;
type
TListTools = class(TObject)
public
// Convert TList<T> to TArray<T>
class function ToArray<T>(AList: TList<T>): TArray<T>;
// Append Array elements in AValues to AList
class procedure AppendList<T>(AList : TList<T>;AValues : TArray<T>);
// Clear List and Append Values to aList
class procedure ToList<T>(AList : TList<T>;AValues : TArray<T>);
end;
implementation
{ TListTools }
class procedure TListTools.AppendList<T>(AList: TList<T>; AValues: TArray<T>);
var
Element : T;
begin
for Element in AValues do
begin
AList.Add(Element);
end;
end;
class function TListTools.ToArray<T>(AList: TList<T>): TArray<T>;
// taken from rtti.pas
var
i : Integer;
begin
SetLength(Result, AList.Count);
for i := 0 to AList.Count - 1 do
Result[i] := AList[i];
end;
class procedure TListTools.ToList<T>(AList: TList<T>; AValues: TArray<T>);
begin
AList.Clear;
AppendList<T>(AList,AValues);
end;
end.
Since TList<T>is the parent class for TObjectList<T> this should work with TObjectList<T> although I have not tried it.
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