TParams.Items Property

Lists the individual field parameters of a TParams object.

Pascal

property Items [Index: Integer]: TParam;

C++

__property TParam Items[int Index];

Description

Use Items to iterate through all the field parameters. Index identifies the index in the range 0 to Count - 1. Items can reference a particular parameter by its index, but the ParamByName method is preferred when working with named parameters, because it does not depend on the order of the parameters.

C++ Examples:

Copy Code

/*
This example requires a TClientDataSet and a button on a form.
Put swSystem in the uses clause for gsAppPath.
*/
void __fastcall TForm1::Button1Click(TObject *Sender)
{
for (int I = 0; I < CDS->Params->Count; I++)
{
  if (CDS->Params->Items[I]->IsNull &&
      CDS->Params->Items[I]->DataType == ftInteger)
    CDS->Params->Items[I]->AsInteger = -1;
}}

#include <swSystem.hpp>

void __fastcall TForm1::FormCreate(TObject *Sender)
{
  CDS->LoadFromFile(gsAppPath + "../CDS.XML");
  CDS->Params->CreateParam(ftInteger, "StateParam", ptInput);
  CDS->Params->CreateParam(ftInteger, "MyParam", ptInput);
}

Delphi Examples:

Copy Code

{
This example fills in the parameters of a client dataset
from the entries of a list box.
} 
procedure TForm1.Button4Click(Sender: TObject);
var
  I: Integer;
  ListItem: string;
begin
  { Call FetchParams to ensure parameters reflect server metadata }
  ClientDataSet1.FetchParams;
  with ClientDataSet1.Params do
  begin
    for I := 0 to Count - 1 do
    begin
      ListItem := ListBox1.Items[I];
      case Items[I].DataType of
        ftString:
          Items[I].AsString := ListItem;
        ftSmallInt:
          Items[I].AsSmallInt := StrToIntDef(ListItem, 0);
        ftInteger:
          Items[I].AsInteger := StrToIntDef(ListItem, 0);
        ftWord:
          Items[I].AsWord := StrToIntDef(ListItem, 0);
        ftBoolean:
          begin
            if ListItem = 'True' then
              Items[I].AsBoolean := True
            else
              Items[I].AsBoolean := False;
          end;
        ftFloat:
          Items[I].AsFloat := StrToFloat(ListItem);
        ftCurrency:
          Items[I].AsCurrency := StrToFloat(ListItem);
        ftBCD:
          Items[I].AsBCD := StrToCurr(ListItem);
        ftDate:
          Items[I].AsDate := StrToDate(ListItem);
        ftTime:
          Items[I].AsTime := StrToTime(ListItem);
        ftDateTime:
          Items[I].AsDateTime := StrToDateTime(ListItem);
      end;
    end;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  ListBox1.Items.Add('Here is a string');
  ListBox1.Items.Add('4');
  ListBox1.Items.Add('3456789');
  ListBox1.Items.Add('34');
  ListBox1.Items.Add('0');
  ListBox1.Items.Add('12.56');
  ListBox1.Items.Add('4.23');
  ListBox1.Items.Add('99.5');
  ListBox1.Items.Add('4/12/53');
  ListBox1.Items.Add('7:45:00');
  ListBox1.Items.Add('4/12/53 7:45:00');

end;

Copy Code

{
This example requires a TClientDataSet and a button on a form.
Put swSystem in the uses clause for gsAppPath.
}
procedure TForm1.Button1Click(Sender: TObject);
var
  I : Integer;
begin
{ Assign -1 to any integer parameter which does not have a value. }
for I := 0 to CDS.Params.Count - 1 do
  if (CDS.Params.Items[I].IsNull) and
     (CDS.Params.Items[I].DataType = ftInteger) then
    { Items is the default property, so you can omit its name }
    CDS.Params[I].AsInteger := -1;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  CDS.LoadFromFile(gsAppPath + 'CDS.XML');
  CDS.Params.CreateParam(ftInteger, 'StateParam', ptInput);
  CDS.Params.CreateParam(ftInteger, 'MyParam', ptInput);
end;