The ASPxGridLookup editor combines the functionality of the DevExpress ASP.NET Drop-down Editor (ASPxDropDownEdit) and ASP.NET Grid View (ASPxGridView) controls to allow end-users to easily select values from a drop-down grid containing lookup items. The ASPxGridView control is seamlessly embedded into the editor's drop-down window, providing the editor with a powerful customizable data-processing and data-representation functionality. The ASPxGridLookup emulates a combo box that allows end-users to select multiple items within its drop-down list in the demo.
One of the major data-processing features adopted from the ASPxGridView is the capability to allow end-users to select multiple list items within the drop-down grid. The selection behavior is controlled by the editor's SelectionMode property, which can be set to ‘Single’ (only one item can be selected within the editor) or ‘Multiple’ (multiple items can be selected within the editor). This demo illustrates how multi-item selection can be implemented easily within ASPxGridLookup using the functionality of the built-in grid.
In this demo, the SelectionMode property is set to ‘Multiple’. End-users can select items by clicking check boxes within the drop-down grid, or by entering tag names separated with a comma into the editor's edit box.
To display check boxes within a drop-down grid, a specific command column is created and its ShowSelectCheckbox property is set to true. In addition, end-users are allowed to filter items within the drop-down grid. This feature is enabled by setting the editor's GridSettings.ShowFilterRow property to true.
Tag names can be entered into the editor’s edit box directly. This functionality is controlled by the TextFormatString property, which defines the column ("TagName") whose values should be entered and represented within the edit box. By default, a semicolon character (;) is used as the value separator. List items (grid rows) that correspond to the tag names entered are automatically selected after the value is submitted (for instance, by pressing the ENTER key).
When used together, all of these features provide end-users with easy-to-use features for searching and selecting the required data.