Mega Code Archive
Extended TStringList
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Title: Extended TStringList
Question: How to use TStringList AddObject Effectively
Answer:
In our application there are situation where we are using many time TStringlist.AddObject
for example in 1 unit I have to use it then
in that unit i have to creatr a class
type
TFloatVal = Class
code: String;
value: Integer;
sum: Real;
end
then to use above class everytime i have to create an Object
say
object: TFloatVal;
object:= TFloatVal.Create;
object.code := somestring;
object.value := someInteger;
object.sum := someFloat;
stringList.AddObject(somestring, object);
This don't end here In our Application many places we have to face this situation, so evreytime we have to do the same process So why dont we use TExtendedStringList
type
TExtendedStringList = class (TStringList)
private
ValList : TStringList;
NameArr : array of string;
public
constructor Create(ANamearray: array of string);
destructor Destroy; override;
procedure AddObjects(const S: string; AValues: array of string);
function GetObjectValuesbyName(const S: string; AName: String):string;
procedure Clear; override;
end;
{ TExtendedStringList }
// Adding Objects values are in array
procedure TExtendedStringList.AddObjects(const S: string;
AValues: array of string);
var
i: Integer;
begin
ValList := TStringList.Create;
for i:= low(NameArr) to High(NameArr) do
ValList.Add(NameArr[i] + '=' + AValues[i]);
AddObject(S, TObject(ValList));
end;
// while clearing freeing all the object that stringlist holds
procedure TExtendedStringList.Clear;
var
i: Integer;
begin
for i:= Count-1 downto 0 do
begin
TStringList(Objects[i]).Free;
end;
inherited;
end;
// Creating with the parameter array of string
constructor TExtendedStringList.Create(ANamearray: array of string);
var
i : Integer;
begin
setLength(NameArr, Length(ANamearray));
for i:= low(ANamearray) to High(ANamearray) do
NameArr[i] := ANamearray[i];
inherited Create;
end;
// Here we are freeing all the object
destructor TExtendedStringList.Destroy;
var
i: Integer;
begin
for i:= Count-1 downto 0 do
begin
TStringList(Objects[i]).Free;
end;
inherited;
end;
//Here we are returing the value of the name
function TExtendedStringList.GetObjectValuesbyName(const S: string;
AName: String): string;
var
indx: Integer;
begin
indx := IndexOf(S);
if (indx = -1) or (ValList.IndexOfName(AName) = -1) then
begin
Result := SysUtils.EmptyStr;
Exit;
end;
Result := TStringList(Objects[indx]).Values[AName] ;
end;
Use of above class
procedure TForm1.Button1Click(Sender: TObject);
var
sum,sum1,sum2: Real;
shallist: TExtendedStringList;
begin
shallist := TExtendedStringList.Create(['Sum','sum1','sum2']) ;
sum := 10.99;
sum1 := 11;
sum2:= 25;
shallist.AddObjects('AA', [Floattostr(sum),Floattostr(sum1),Floattostr(sum2)]);
sum := 12.99;
sum1 := 21;
sum2:= 45;
shallist.AddObjects('BB', [Floattostr(sum),Floattostr(sum1),Floattostr(sum2)]);
showmessage(shallist.GetObjectValuesbyName('AA', 'sum2'));
shallist.Free;
end;
Any Comment and suggestion are welcome ya we can make it more effective.
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