TFieldGetData (C++)
Description
This example requires a button, a test edit, and a populated ClientDataSet. Pipe the ClientDataSet through a DataSource to a DGGrid or DBNavigator to control the current field. Cast the data correctly according to the field type when assigning to the test edit.
Code
void __fastcall TForm1::Button1Click(TObject *Sender)
{
// Retrieve the "raw" data from Field1
if (!CDS->Fields->Fields[0]->IsBlob()) // __classid(TField) GetData does not work for BLOB fields.
{
void *MyBuffer = malloc(CDS->Fields->Fields[0]->DataSize);
try
{
if (!CDS->Fields->Fields[0]->GetData(MyBuffer))
MessageDlg(CDS->Fields->Fields[0]->DisplayName + "is blank.", mtInformation, TMsgDlgButtons() << mbOK,0);
else
// Do something with the data;
Edit1->Text = reinterpret_cast<char *>(MyBuffer); // For a string field
}
__finally
{
free(MyBuffer);
}
}
}
__fastcall TForm1::TForm1(TComponent* Owner)
: TForm(Owner)
{
CDS->LoadFromFile("../CDS.XML");
}
Uses
- Data.DB.TField.DataSize ( fr | de | ja )
- Data.DB.TField.GetData ( fr | de | ja )
- Data.DB.TBlobField.IsBlob ( fr | de | ja )
- Data.DB.TField.DisplayName ( fr | de | ja )