TDataSetAfterDelete (C++)

Description

This example displays a message on the form's status bar indicating the record count after a record is deleted. Set the StatusBar SimplePanel property to True.

Code

void __fastcall TForm1::Table1AfterDelete(TDataSet *DataSet)
{
  StatusBar1->SimpleText = Format(
	"There are now %d records in the table",
	ARRAYOFCONST(((int)DataSet->RecordCount)));
}

void __fastcall TForm1::Button1Click(TObject *Sender)
{
  Table1->Delete();
}

__fastcall TForm1::TForm1(TComponent* Owner)
  : TForm(Owner)
{
  Table1 = new TTable(Form1);
  Table1->Active = false; // The Table component must not be active.
  Table1->DatabaseName = "DBDEMOS";
  Table1->TableType = ttParadox;
  Table1->TableName = "CustInfo";
  Table1->Active = False;
  if (!Table1->Exists) // Do not overwrite an existing table.
  {
	Table1->Close();
	Table1->DeleteTable();
  }
  // The Table component must not be active.
  // First, describe the type of table and give
  // it a name.
  // Next, describe the fields in the table.
  Table1->FieldDefs->Clear();
  TFieldDef *pNewDef = Table1->FieldDefs->AddFieldDef();
  pNewDef->Name = "Field1";
  pNewDef->DataType = ftInteger;
  pNewDef->Required = true;
  pNewDef = Table1->FieldDefs->AddFieldDef();
  pNewDef->Name = "Field2";
  pNewDef->DataType = ftString;
  pNewDef->Size = 30;
  // Next, describe any indexes.
  Table1->IndexDefs->Clear();
  /* The first index has no name because it is a Paradox primary key. */
  Table1->IndexDefs->Add("","Field1", TIndexOptions() <<ixPrimary << ixUnique);
  Table1->IndexDefs->Add("Fld2Index","Field2", TIndexOptions() << ixCaseInsensitive);
  // Now that you have specified what you want, create the table.
  Table1->CreateTable();
  Table1->Active = True;
  for (int i = 1; i <= 20; i++)
	Table1->AppendRecord(ARRAYOFCONST((i*111, i*222)));
  DS2->DataSet = Table1;
  DBGrid2->DataSource->DataSet = Table1;
  Table1->AfterDelete = Table1AfterDelete;
  Table1->Active = True;
}

Uses

• Data.DB.TDataSet.AfterDelete ( fr | de | ja )
• System.SysUtils.Format ( fr | de | ja )
• System.AnsiStrings.Format ( fr | de | ja )