TCustomConnection.DataSetCount Property

Indicates the number of datasets associated with the connection component.

Pascal

property DataSetCount: Integer;

C++

__property int DataSetCount;

Description

Use DataSetCount to determine the number of datasets listed by the DataSets property. Depending on the TCustomConnection descendant, DataSets may include only the active datasets that use the connection component (as is the case with TDatabase and TSQLConnection), or it may list all datasets, regardless of whether they are active (as is the case with TADODatabase and DataSnap connection components TSOAPConnection). If DataSets includes only active datasets, the value of DataSetCount changes when datasets are opened and closed.

Use DataSetCount as an upper bound when iterating through the DataSets property.

Delphi Examples:

Copy Code

{
The following code fragment illustrates how DataSets and
DataSetCount can be used to ensure that an action is taken
for every open dataset.  Assign CheckButtonActive as the
AfterClose and AfterOpen event handlers for TClientDataSet1.
}
procedure TForm1.Button1Click(Sender: TObject);
var
  I: Integer;
begin
  if not RemoteServer1.Connected then
    RemoteServer1.Connected := True;
  ClientDataSet1.Close;
  with RemoteServer1 do
  begin
    for I := 0 to DataSetCount - 1 do
      DataSets[I].EnableControls;
  end;
  ClientDataSet1.Open;
end;

procedure TForm1.Button3Click(Sender: TObject);
var
  I: Integer;
begin
  ClientDataSet1.Close;
  RemoteServer1.Connected := False;
  with RemoteServer1 do
  begin
    for I := 0 to DataSetCount - 1 do
      DataSets[I].DisableControls;
  end;
end;

procedure TForm1.CheckButtonActive(DataSet: TDataSet);
begin
  Button1.Enabled := not ClientDataSet1.Active;
  Button2.Enabled := ClientDataSet1.Active;
  Button3.Enabled := ClientDataSet1.Active;
end;