This topic has not yet been rated - Rate this topic

MapEnumerator Class

Dynamics AX 4.0

Dynamics AX 2009

The MapEnumerator class allows you to traverse through the elements within a map.

Copy


class MapEnumerator extends Object

Run On

Called

Methods

Method	Description
current	Obsolete; use MapEnumerator.currentKey instead.
currentKey	Returns the key from the (key, value) pair that is currently pointed to by the enumerator.
currentValue	Returns the value from the (key, value) pair that is currently pointed to by the enumerator.
definitionString	Returns a description of the enumerator.
moveNext	Determines whether the enumerator points to a valid map element.
new	Creates an enumerator for a map.
reset	Moves the enumerator to point to just before the first element in the map.
toString	Returns a description of the content of the element in the map that the enumerator is currently pointing to.

Remarks

Map enumerators start before the first element in the list. You must call the MapEnumerator.moveNext method to make it point to the first element in the list.

It is a best practice to use the MapEnumerator class instead of the MapIterator class, because enumerators are automatically created on the same tier as the map (when calling the Map.getEnumerator method). Using the MapIterator class avoids a potential problem in code marked as Called from, where the iterator and map can end up on separate tiers. In addition, because map enumerators require less code than map iterators, they perform slightly better. The only situation where you have to use a map iterator, is when you want to delete items from a list (use the MapIterator.delete method).

Example

The following example creates a map for the tables contained within a project. An enumerator is created for the map, and the MapEnumerator.moveNext method is used to iterate over the tables. The MapEnumerator.currentKey method is used to add the name of each table in the original map as the key for each element in a new map, and a DictTable object is created as the value for each element in the new map. (DictTable allows you to access information about a table.)

Copy

{
    Map map = Map::create(
        SysUmlDataModel::getProjectTablesClient(projectNode));
    MapEnumerator enum = map.getEnumerator();
    TableName tableName;
;

    while (enum.moveNext())
    {
        tableName = enum.currentKey();
        map.insert(tableName, new DictTable(tablename2id(tableName)));
    }
    return map;
}