Ngược lại với thành phần trình đơn riêng của mình, bạn cần phải rõ ràng tên các mục menu khi bạn thêm vào để tạo thành. Bạn có thể làm điều này trong một trong hai cách: • Trực tiếp nhập giá trị cho tài sản Tên. • Nhập các giá trị | Viewing and editing data with TDBGrid cells. For example you can use a blank column to display aggregated values on the last record of a group of records that the aggregate summarizes. Another possibility is to display a bitmap or bar chart that graphically depicts some aspect of the record s data. Two or more persistent columns can be associated with the same field in a dataset. For example you might display a part number field at the left and right extremes of a wide grid to make it easier to find the part number without having to scroll the grid. Note Because persistent columns do not have to be associated with a field in a dataset and because multiple columns can reference the same field a customized grid s FieldCount property can be less than or equal to the grid s column count. Also note that if the currently selected column in a customized grid is not associated with a field the grid s SelectedField property is NULL and the SelectedIndex property is -1. Persistent columns can be configured to display grid cells as a combo box drop-down list of lookup values from another dataset or from a static pick list or as an ellipsis button . in a cell that can be clicked upon to launch special data viewers or dialogs related to the current cell. Creating persistent columns To customize the appearance of grid at design time you invoke the Columns editor to create a set of persistent column objects for the grid. At runtime the State property for a grid with persistent column objects is automatically set to csCustomized. To create persistent columns for a grid control 1 Select the grid component in the form. 2 Invoke the Columns editor by double clicking on the grid s Columns property in the Object Inspector. The Columns list box displays the persistent columns that have been defined for the selected grid. When you first bring up the Columns editor this list is empty because the grid is in its default state containing only dynamic columns. You can create persistent .
