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ComboBox.ObjectCollection.Add Method

Adds an item to the list of items for a ComboBox.

[Visual Basic]
Public Function Add( _
   ByVal item As Object _
) As Integer
public int Add(
 object item
public: int Add(
 Object* item
public function Add(
   item : Object
) : int;


An object representing the item to add to the collection.

Return Value

The zero-based index of the item in the collection.


Exception Type Condition
ArgumentNullException The item parameter was a null reference (Nothing in Visual Basic).


This method adds an item to the combo box. If the Sorted property of the ComboBox is set to true, the item is inserted into the list alphabetically. Otherwise, the item is inserted at the end of the list.

A visual representation of the item is displayed in the combo box. This content representation is specified by the DisplayMember property. If the DisplayMember property is a null reference (Nothing in Visual Basic), the item's ToString method is called to obtain the string that is displayed in the combo box; otherwise, the property of the stored object as specified by the DisplayMember property is displayed. A SystemException occurs if there is insufficient space available to store the new item. To add a set of items to the combo box it is best to use the AddRange method. If you choose to use the Add method to add a number of items to the combo box, use the BeginUpdate method to suspend repainting during your add and the EndUpdate method to resume repainting. You can use the Insert method to specify the location in the list where an item is added. When an object is added to the collection, the ComboBox calls the object's ToString method to obtain the string to display in the list.


Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

See Also

ComboBox.ObjectCollection Class | ComboBox.ObjectCollection Members | System.Windows.Forms Namespace