Creating new Field Definition Classes

Creating a field definition class for a new input control is simply a case of descending a new class from BaseFieldDefinition and overriding the BuildInputControl() method.

As an example, we'll see how to implement a fictional numeric integer input control, called IntegerEditor.

First, create a new class descended from BaseFieldDefinition:

public class IntegerEditorFieldDefinition : BaseFieldDefinition {


Our fictional control has two properties we want to be able to customize - MinValue and MaxValue . To allow this, we'll add similar properties to our new class:

    public int MinValue { get; set; }

    public int MaxValue { get; set; }

Next, we need to override BuildInputControl to create an instance of IntegerEditor. The method needs to:
  1. Create an instance of IntegerEditor
  2. Set up a binding for the IntegerEditor.Value property
  3. Optionally set up a Binding for the IsEnabled property
  4. Set the InputControl and ContainerControl properties

    protected override void BuildInputControl() {
        IntegerEditor editor = new IntegerEditor() {
            MinValue = this.MinValue,
            MaxValue = this.MaxValue
        Binding valueBinding = new Binding(PropertyName);
        BindingOperations.SetBinding(editor, IntegerEditor.ValueProperty, valueBinding);
        if (!String.IsNullOrWhiteSpace(EnabledPropertyName))
            Binding enabledBinding = new Binding(EnabledPropertyName);
            if (InvertEnabledState)
                // InverseBooleanConverter is in the AutoForm namespace
                enabledBinding.Converter = new InverseBooleanConverter();
            BindingOperations.SetBinding(textBox, TextBox.IsEnabledProperty, enabledBinding);
        ContainerControl = InputControl = textBox;

All that remains is to register the new field definition:

    FieldDefinitionRegistry.Register<int, IntegerEditorFieldDefinition>();

Last edited Oct 18, 2014 at 5:03 PM by DevKnightlie, version 1