A collection of strings that represent all the items in a drop-down form field.

To learn more, visit the Working with Fields documentation article.

public class DropDownItemCollection : IEnumerable<string>


Count { get; }Gets the number of elements contained in the collection.
Item { get; set; }Gets or sets the element at the specified index.


Add(string)Adds a string to the end of the collection.
Clear()Removes all elements from the collection.
Contains(string)Determines whether the collection contains the specified value.
GetEnumerator()Returns an enumerator object that can be used to iterate over all items in the collection.
IndexOf(string)Returns the zero-based index of the specified value in the collection.
Insert(int, string)Inserts a string into the collection at the specified index.
Remove(string)Removes the specified value from the collection.
RemoveAt(int)Removes a value at the specified index.


Shows how to insert a combo box field, and edit the elements in its item collection.

Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);

// Insert a combo box, and then verify its collection of drop-down items.
// In Microsoft Word, the user will click the combo box,
// and then choose one of the items of text in the collection to display.
string[] items = { "One", "Two", "Three" };
FormField comboBoxField = builder.InsertComboBox("DropDown", items, 0);
DropDownItemCollection dropDownItems = comboBoxField.DropDownItems;

Assert.AreEqual(3, dropDownItems.Count);
Assert.AreEqual("One", dropDownItems[0]);
Assert.AreEqual(1, dropDownItems.IndexOf("Two"));

// There are two ways of adding a new item to an existing collection of drop-down box items.
// 1 -  Append an item to the end of the collection:

// 2 -  Insert an item before another item at a specified index:
dropDownItems.Insert(3, "Three and a half");

Assert.AreEqual(5, dropDownItems.Count);

// Iterate over the collection and print every element.
using (IEnumerator<string> dropDownCollectionEnumerator = dropDownItems.GetEnumerator())
    while (dropDownCollectionEnumerator.MoveNext())

// There are two ways of removing elements from a collection of drop-down items.
// 1 -  Remove an item with contents equal to the passed string:

// 2 -  Remove an item at an index:

Assert.AreEqual(3, dropDownItems.Count);
Assert.IsFalse(dropDownItems.Contains("Three and a half"));

doc.Save(ArtifactsDir + "FormFields.DropDownItemCollection.html");

// Empty the whole collection of drop-down items.

See Also