ListBox Class |  |
Create a list box.
Inheritance HierarchyNamespace: VO
Assembly: VOGUIClasses (in VOGUIClasses.dll) Version: 2.21
SyntaxThe ListBox type exposes the following members.
ConstructorsProperties| Name | Description | |||
|---|---|---|---|---|
 | Background |
The brush used for painting the background of the control. For example, in a single line edit control, the background is the color behind the text in the edit control.
(Inherited from Control.) | ||
| Caption |
The string representing the caption of the list box.
(Overrides Caption.) | ||
| ContextMenu |
A menu object representing the local pop-up menu for a control.
(Inherited from Control.) | ||
| ControlFont |
The font used to draw the text in the control.
(Inherited from TextControl.) | ||
| ControlID |
A number between 1 and 8000 representing the unique ID of a control
(Inherited from Control.) | ||
| CurrentItem |
A string representing the displayed list box or combo box item selected.
(Overrides CurrentItem.) | ||
| CurrentItemNo |
A numeric value, between 1 and the ListBox:ItemCount, indicating which item is currently selected.
(Overrides CurrentItemNo.) | ||
| CurrentText |
ListBox:CurrentText is set to the NULL_STRING, since there is no text editing for list boxes.
(Overrides CurrentText.) | ||
| FieldSpec |
The field specification connected to the control.
(Inherited from Control.) | ||
| HyperLabel |
The hyperlabel connected to the control.
(Inherited from Control.) | ||
| Length |
A numeric value representing the number of characters in the control.
(Inherited from TextControl.) | ||
| Modified |
A logical value that is set to TRUE when a standard edit control or editable combo box is in the process of being modified.
(Inherited from Control.) | ||
| MultiSelection |
Used to identify if the ListBox supports multiple selections.
| ||
| Name |
A string representing the name of the control.
(Inherited from Control.) | ||
| NameSym |
A symbol representing the name of the control.
(Inherited from Control.) | ||
| Origin |
A point representing the location of a control on its owner window, in canvas coordinates.
(Inherited from Control.) | ||
| Owner |
The owner window of a control.
(Inherited from Control.) | ||
| OwnerAlignment |
Constant representing how the window will be aligned within its owner window.
(Inherited from Control.) | ||
| ReadOnly |
Is the control readonly ?
(Inherited from Control.) | ||
| SelectedCount |
A numeric value representing the total number of items that are currently selected in a multiple selection list box.
| ||
| SelectedFile | |||
| Server |
The server object that currently connected to this control. If no server is connected, the value is NIL.
(Inherited from Control.) | ||
| Size |
A dimension representing the size of a control.
(Inherited from Control.) | ||
| Status |
A hyperlabel indicating the status of the control after a validation attempt or other action.
(Inherited from Control.) | ||
| TextColor |
The color used to draw the text in the control. (Refer to the Color:Init() method for details on specifying a color object.)
(Inherited from TextControl.) | ||
| TextValue |
A string representing the display value (first array's element) for the currently selected item.
(Overrides TextValue.) | ||
| ToolTipText |
String value representing the tooltip text used when the user moves the mouse pointer over the control.
(Inherited from Control.) | ||
| UseHLForToolTip |
Logical value determining whether the descriptive text of a control's Hyperlabel should be used as the tooltip text.
(Inherited from Control.) | ||
 | Value |
The value held in the control, in whatever data type the control holds.
(Inherited from Control.) | ||
| ValueChanged |
A logical value representing whether the control's Value has been changed from its prior setting.
(Inherited from Control.) |
Methods| Name | Description | |
|---|---|---|
 | Activate |
Provide a method that is invoked when the control has focus and a window is activated. (Inherited from Control.) |
| AddItem(Usual, Usual) |
Add a new item to a list box at a specified position.
(Inherited from BaseListBox.) |
| AddItem(Usual, Usual, Usual) |
Add a new item to a list box at a specified position.
|
| AsString |
Return the contents of the control (or its identifying label).
(Inherited from Control.) |
| ChangeSelected |
Change a range of items in a multiple selection list box to a specified selection.
|
| Clear | (Overrides Clear.) |
| ClearSelection |
Clear a multiple selection list box of all selections.
|
| Deactivate |
Provide a method that is invoked when the control has focus and a window is deactivated. (Inherited from Control.) |
| DEFAULT | Call the default windows procedure for a control and set the EventReturnValue. (Inherited from Control.) |
| DeleteItem |
Remove an item from a list box.
(Overrides DeleteItem(Usual).) |
| DeselectItem |
Turn off the selection of a specified item in a list box.
|
| Destroy |
Provide a method to de-instantiate a BaseListBox object.
(Inherited from BaseListBox.) |
| Disable |
Disable a control (until a subsequent call to Control:Enable()).
(Inherited from Control.) |
| DisableTheme |
Disable the WinXP theme for a control.
(Inherited from Control.) |
| Dispatch |
Provide the prototype dispatcher for events within the system when the control has focus; routing various events to their appropriate event handlers. (Inherited from Control.) |
| Enable |
Enable a control that was previously disabled.
(Inherited from Control.) |
| EnableItemDrag |
Turn the list box into a drag list box.
|
| Expose |
Provide a method that is invoked when the control has focus and whenever part of the window needs repainting. (Inherited from Control.) |
| FillUsing |
Specify the set of values to be displayed in the list box, using an array or a data server. These values act as a constraint on the values that may be entered in the list box, and optionally as a translation between program values and display values.
|
| FindItem |
Search a list box for a specified string, and return the location of the first item in the list box that matches it.
(Inherited from BaseListBox.) |
| FirstSelected |
Returns the position of the first item selected in a multiple selection list box, or 0 if no item is selected.
|
| FocusChange |
Provide a method that is invoked when the control has focus and the input focus changes from the current control to another (or vice versa). (Inherited from Control.) |
| Font |
Change the current font of the text control.
(Inherited from TextControl.) |
| GetExStyle |
Retrieve the Ex styles for the control.
(Inherited from Control.) |
| GetItem |
Retrieve the text of a specified list box item.
(Inherited from BaseListBox.) |
| GetItemValue |
Retrieve the value of a specified list box item.
|
| GetStyle |
Retrieve the styles for the control.
(Inherited from Control.) |
| Handle |
Return the handle for a control.
(Inherited from Control.) |
| HasBorder | Check if a border has been set for the control (Inherited from Control.) |
| HasStyle | Check if a style value has been set for the control (Inherited from Control.) |
| Hide |
Hide a control so it is not visible (until a subsequent call to Control:Show()).
(Inherited from Control.) |
| HorizontalScroll |
Provide a method that is invoked when the control has focus and a horizontal scroll bar is scrolled. (Inherited from Control.) |
| Ime |
Return and optionally set whether Input Method Editor is enabled for this text control.
(Inherited from TextControl.) |
| IsEnabled |
Report if this control is currently enabled.
(Inherited from Control.) |
| IsExStyle | Check if a exstyle value has been set for the control (Inherited from Control.) |
| IsReadOnly |
Report if this control is currently readonly.
(Inherited from Control.) |
| IsSelected |
Determine if the list box item at the specified index position is selected.
|
| IsStyle | Check if a style value has been set for the control (Inherited from Control.) |
| IsVisible |
Report if this control is visible (completely or partially) or hidden.
(Inherited from Control.) |
| KeyDown |
Provide a method that is invoked when the control has focus and a key on the keyboard is pressed. (Inherited from Control.) |
| KeyUp |
Provide a method that is invoked when the control has focus and a key on the keyboard is released. (Inherited from Control.) |
| LinkDF |
Connect a control to a data field in a data server.
(Inherited from Control.) |
| ListFiles |
Fill a list box with the names of all files that match the specified path or file name.
|
| MenuInit |
Provide a method that is invoked when a pop-up menu owned by the control is about to pop up.
(Inherited from Control.) |
| MenuSelect |
Provide a method that is invoked when an item on a menu owned by the control is highlighted.
(Inherited from Control.) |
| MouseButtonDoubleClick |
Provide a method that is invoked when the control has focus, the mouse pointer is positioned over the window, and a mouse button is double-clicked. (Inherited from Control.) |
| MouseButtonDown |
Provide a method that is invoked when the control has focus, the mouse pointer is positioned over the window, and a mouse button is clicked. (Inherited from Control.) |
| MouseButtonUp |
Provide a method that is invoked when the control has focus, the mouse pointer is positioned over the window, and a mouse button is released.
(Inherited from Control.) |
| MouseDrag |
Provide a method that is invoked when the control has focus and a mouse with one or more buttons clicked is moved in the window.
(Inherited from Control.) |
| MouseMove |
Provide a method that is invoked when the control has focus and the mouse is moved in the control.
(Inherited from Control.) |
| Move |
Provide a method that is invoked when the control has focus and the control is moved (either by the user or by the application).
(Inherited from Control.) |
| NextSelected |
After calling ListBox:FirstSelected(), this method is used to cycle through the remaining items selected in a multiple selection list box.
|
| OverRide | This is a compatibility method that is no longer used or needed. (Inherited from Control.) |
| PerformValidations |
Perform all the validations defined to this control's field specification (for example, required, maximum and minimum digits, maximum and minimum value, validation rule) and return the result of the test.
(Inherited from Control.) |
| RegisterTimer |
Register a timer method to be invoked for the control.
(Inherited from Control.) |
| RemoveEditBalloonTip |
Removes the current BallonTip from the Edit control that has inherited from this class.
(Inherited from TextControl.) |
| RePaint |
Send an ExposeEvent to repaint the control
(Inherited from Control.) |
| Resize |
Provide a method that is invoked when the control has focus and the control changes size.
(Inherited from Control.) |
| RestoreUpdate |
Resume all drawing updates for a control (after Control:SuspendUpdate() is called).
(Inherited from Control.) |
| SelectItem |
Turn on the selection of an item in a list box.
|
| SetCueBanner |
Add a cue banner to the Edit control that has inherited from this class.
(Inherited from TextControl.) |
| SetExStyle |
Set the exstyle for the control.
(Inherited from Control.) |
| SetFocus |
Pass input focus to a control, thereby directing all mouse and keyboard input to the control.
(Inherited from Control.) |
| SetParent |
Change the parent handle for the control.
(Inherited from Control.) |
| SetStyle |
Set the style for the control.
(Inherited from Control.) |
| SetTop |
Move a specified item to the top of the list box.
(Inherited from BaseListBox.) |
| Show |
Display a control so it is visible.
(Inherited from Control.) |
| ShowEditBalloonTip |
Add a BallonTip to the Edit control that has inherited from this class.
(Inherited from TextControl.) |
| SuspendUpdate |
Temporarily suspend all drawing updates for a control; drawing resumes with a call to Control:RestoreUpdate().
(Inherited from Control.) |
| Timer |
Provide a method to be invoked at specific intervals defined when the timer is registered though the RegisterTimer() method.
(Inherited from Control.) |
| ValidateControl | This method validates if the control has been created and when not then it triggers the control creation (Inherited from Control.) |
| VerticalScroll |
Provide a method that is invoked when the control has focus and a vertical scroll bar is scrolled.
(Inherited from Control.) |
Fields| Name | Description | |
|---|---|---|
 | EventReturnValue | (Inherited from Control.) |
| oCargo | Cargo slot. (Inherited from VObject.) |
Remarks
List boxes and combo boxes display a list of items or choices to the user. The list box methods will allow you to add, arrange, remove, and interrogate the list of items. When one of the items is selected, ListBox:CurrentItem, ListBox:CurrentItemNo, ListBox:TextValue, and ListBox:Value are updated. Either a one-dimensional or two-dimensional array is specified in the FillUsing() method, with a row for each of the items available for selection. With a two-dimensional array, the first element is called the display value, and the second element is called the return value. When an item is selected, ListBox:TextValue contains the first element (the display value), and ListBox:Value contains the second element (the return value). If no item is selected, ListBox:TextValue is NULL_STRING and ListBox:Value is NIL.
A list box may be bound to a field (character, date, logical, numeric, or memo) in a server. The field's data value is stored in ListBox:Value. The list box compares the data value to the second element values specified in the FillUsing() array, and if a match is found, the first element (the display value) is stored in ListBox:TextValue. In a "no-match" situation, the list box shows no item selected, ListBox:CurrentItem is NULL_STRING, ListBox:CurrentItemNo is set to 0, and ListBox:TextValue and ListBox:Value reflect the field contents. If an item is selected, ListBox:CurrentItemNo is set to a number between 1 and ListBox:ItemCount, and the corresponding second element is stored as ListBox:Value and as the field's data value.
You can also create a multiple selection list box, which allows you to manage multiple items within a list box. Any number of items in a list box can be selected together (referred to as multiple selection). Each item is toggled on/off each time the user clicks on it.
A multiple selection list box is created by selecting the LBOXMULTIPLESEL style when creating a ListBox object. Certain properties and methods of this class apply specifically to multiple selection list boxes, including SelectedCount access, ChangeSelected(), ClearSelection(), DeselectItem(), FirstSelected(), NextSelected(), and SelectItem().
 Tip |
|---|
| All array index references start at 1. |
Examples
This example creates and fills a list box with a list of animals:
A X# list box is equivalent to a Windows list box with the LBS_NOTIFY and LBS_SORT styles.
List boxes are normally specified in the resource entity like this:
X#
1CLASS MyWindow INHERIT TopAppWindow 2HIDDEN oLB AS OBJECT 3METHOD Init() CLASS MyWindow 4SUPER:Init() 5oLB := ListBox{SELF,42,Point{10,10},; 6Dimension{100,40}} 7oLB:AddItem("Pig") 8oLB:AddItem("Cow") 9oLB:AddItem("Horse") 10oLB:Show()
X#
1RESOURCE IDD_ABOUT DIALOG 20, 20, 160, 80 2STYLE WS_POPUP | WS_DLGFRAME 3BEGIN 4LISTBOX IDL_ITEMLIST, 10, 10, 90, 40 5END
See Also