4、 DrawDataCell事件是绘制单元格，当获得焦点网格所对应的字段与组合框所对应的字段一致时，移动组合框到获得焦点的网格上，并且 使组合框可视，从而达到在DBGrid指定列上显示DBComboBox的功能。设置DBGrid1的OnDrawDataCell事件如下： procedure TForm1.DBGrid1DrawDataCell(Sender: TObject; const Rect: TRect; Field: TField; State: TGridDrawState); begin if (gdFocused in State) then begin if (Field.FieldName = DBComboBox1.DataField ) then begin DBComboBox1.Left := Rect.Left + DBGrid1.Left; DBComboBox1.Top := Rect.Top + DBGrid1.top; DBComboBox1.Width := Rect.Right - Rect.Left; DBComboBox1.Height := Rect.Bottom - Rect.Top; DBComboBox1.Visible := True; end; end; end;
5、 DBGrid指定单元格未获得焦点时不显示DBComboBox，设置DBGrid1的OnColExit事件如下： procedure TForm1.DBGrid1ColExit(Sender: TObject); begin If DBGrid1.SelectedField.FieldName = DBComboBox1.DataField then begin DBComboBox1.Visible := false; end; end;
6、 当DBGrid指定列获得焦点时DrawDataCell事件只是绘制单元格，并显示DBComboBox，但是DBComboBox并没有获得焦点，数据的输入还是在单元格上进行。在DBGrid1的KeyPress事件中调用SendMessage这个 Windows API函数将数据输入传输到DBComboBox上，从而达到在DBComboBox上进行数据输入。因此还要设置KeyPress事件如下： procedure TForm1.DBGrid1KeyPress(Sender: TObject; var Key: Char); begin if (key < > chr(9)) then begin if (DBGrid1.SelectedField.FieldName =DBComboBox1.DataField) then begin DBComboBox1.SetFocus; SendMessage(DBComboBox1.Handle, WM_Char, Word(Key), 0); end; end; end;
