Other Instructions
Type...End Type
Une structure est une collection de variables qui peuvent être manipulées comme une seule entité. En d'autres termes, on peut faire l'analogie entre une structure et une enregistrement, ou un morceau d'enregistrement.
L'API utilise souvent des structures prédefinies mais ce sont des structures UNO, un type de structure très specialisé
Définition
Avec l'instruction Type...End Type, vous pouvez définir votre propre structure (non-UNO)
Type aMenuItem 'déclare le nom de la structure 'Défini les champs dans la structure. 'chaque définition ressemble à une instruction DIM, sabs la commande "Dim" aCommand as String aText as String End Type 'ferme la définition
Instance
La définition Type n'est qu'un modèle, pas l'ensemble de variables existantes. Pour avoir une instance de ce type, véritables variables qui peuvent etre manipulées, utiliser l'instruction Dim ... as New :
Dim maItem as New aMenuItem
Portée
La définition de Type doit être écrite au début du module (avant lea première instruction Sub ou Function)
Pour le version 3.0 de OpenOffice.org, contrairement aux variables, il est impossible de rendre le type déclaré disponible à un autre module.
Une instance du nouveau type est une variable et répond donc aux règles de portées des variables (voir Scope and Life Span of Variables).
Un exemple de définition et d'utilisation d'un champ dans une instance est donné dans la section With...End With.
With...End With
Qualifiers
In general, Basic does not look inside a container, such as an Object, to see what names might be defined there. If you want to use such a name, you must tell Basic where to look. You do that by using the name of the object as a qualifier. Write it before the inner name, and separate it by a period:
MyObject.SomeName
Since containers may hold other containers, you may need more than one qualifier. Write the qualifiers in order, from outer to inner:
OuterObject.InnerObject.FarInsideObject.SomeName
These names may also be described as, "concatenated with the dot-operator ('.')".
The With Alternative
The With...End With bracketing statements provide an alternative to writing out all the qualifiers, every time - and some of the qualifiers in the API can be quite long. You specify the qualifiers in the With statement. Until Basic encounters the End With statement, it looks for partly-qualified names: names that begin with a period (unary dot-operator). The compiler uses the qualifiers from the With as though they were written in front of the partly-qualified name.
Example 1: A User-defined Struct
This example shows how you may define and use a struct, and how to reference the items within it, both with and without With. Either way, the names of the data fields (from the Type definition) must be qualified by the name of the instance (from the Dim statement).
Type aMenuItem aCommand as String aText as String End Type Sub Main 'Create an instance of the user-defined struct. ' Note the keyword, "New". Dim maItem as New aMenuItem With maItem .aCommand = ".uno:Copy" .aText = "~Copy" End With MsgBox "Command: " & maItem.aCommand & Chr(13) _ & "Text: " & maItem.aText End Sub
Example 2: Case statement
In Cells and Ranges, the following example has the qualifiers in the Case statements written out completely, for clarity. You can write it more easily, this way:
Dim Doc As Object Dim Sheet As Object Dim Cell As Object Doc = StarDesktop.CurrentComponent Sheet = Doc.Sheets(0) Cell = Sheet.getCellByPosition(1,1) 'Cell "B2" (0-based!) Cell.Value = 1000 With com.sun.star.table.CellContentType Select Case Cell.Type Case .EMPTY MsgBox "Content: Empty" Case .VALUE MsgBox "Content: Value" Case .TEXT MsgBox "Content: Text" Case .FORMULA MsgBox "Content: Formula" End Select End With
Notice that the With construct must be entirely outside of the Select construct.
Content on this page is licensed under the Public Documentation License (PDL). |