This article describes the following topics:
This class corresponds to the FormFieldType.ComboBox enum value and represents a drop down control with choices that can be selected.
ComboBoxField provides the following properties:
Value: Gets or sets single choice that is selected. This choice is represented by the ChoiceOption class that has a single Value and UserInterfaceValue properties. The UserInterfaceValue property is optional and when null, the Value property is used to display the choice in the user interface.
DefaultValue: Gets or sets the default selected choice used when the AcroForm is reset to its default values.
Widgets: The collection of Widget annotations, which represent the field on the PDF pages. The widgets are created by using the collection's AddWidget() method and can be removed by using the Remove() method. As the widget collection implements the IEnumerable interface, the available widget instances can be iterated.
Options: A ChoiceOptionCollection instance containing all available choices for this field. In order to modify this collection, you can use its indexer property and its Add(), RemoveAt() and Clear() methods. Each ChoiceOption instance can be added only once to such a collection. If you try adding the same instance more than once in the collection, an exception will be thrown.
ShouldCommitOnSelectionChange: Boolean value indicating whether to commit the selected value on selection change.
HasEditableTextBox: Boolean value indicating whether the drop down should provide additional text box input, allowing the user to input value that may be different from the provided choices.
ShouldSpellCheck: Boolean value indicating whether the text should be spell checked during its input.
Example 1: Create a ComboBoxField and add it to a page
ComboBoxField comboBoxField = new ComboBoxField("SampleComboBox"); comboBoxField.Options.Add(new ChoiceOption("First Value")); comboBoxField.Options.Add(new ChoiceOption("Second Value")); comboBoxField.Options.Add(new ChoiceOption("Third Value")); comboBoxField.Value = comboBoxField.Options; VariableContentWidget widget = comboBoxField.Widgets.AddWidget(); widget.Rect = new Rect(100, 100, 200, 30); widget.RecalculateContent(); document.AcroForm.FormFields.Add(comboBoxField); document.Pages.Annotations.Add(widget);