Configuring Interaction Providers

Updated on Aug 5, 2026

RadInlineAIAssistant does not read from or write to its target element directly. Instead, it delegates all of that to an InteractionProvider—an implementation of the IInlineAssistantInteractionProvider interface, set through the InteractionProvider property.

The IInlineAssistantInteractionProvider Interface

IInlineAssistantInteractionProvider exposes the following members:

• TargetElement—Gets the FrameworkElement that the assistant interacts with. It is used as the Popup placement target.
• FullText—Gets the full text of the target element.
• SelectedText—Gets the currently selected text in the target element.
• InsertText(string)—Inserts the specified text at the current caret position.
• ReplaceSelectedText(string)—Replaces the currently selected text with the specified text.
• CanInsertText(string)—Determines whether text can currently be inserted. Backs the CanExecute state of the Insert command.
• CanReplaceSelectedText(string)—Determines whether the current selection can be replaced. Backs the CanExecute state of the Replace command.
• GetPosition()—Returns the screen point where the assistant popup should open, or null if it should not open (for example, because the caret is currently scrolled outside of the visible viewport).

InteractionProvider must be set before IsOpen is set to true. Otherwise, an InvalidOperationException is thrown.

Built-in Providers

The following built-in providers are available:

• InlineAIAssistantTextBoxProvider—Implements the interface for a TextBox. It is created automatically for you when the assistant is attached to a TextBox and no InteractionProvider has been set yet.
• InlineAIAssistantRadRichTextBoxProvider—Implements the interface for a RadRichTextBox, reading and writing the document's plain text. It ships with the RichTextBox assembly and is not created automatically—set it explicitly. To use it, add a reference to the assembly (or NuGet package) that contains the RadRichTextBox control, as described in the RadRichTextBox Getting Started article.

Attaching a RadInlineAIAssistant to a RadRichTextBox

C#

RadInlineAIAssistant assistant = new RadInlineAIAssistant();
assistant.InteractionProvider = new InlineAIAssistantRadRichTextBoxProvider(this.radRichTextBox);
assistant.PromptRequest += this.OnPromptRequest;

RadInlineAIAssistant.SetInlineAIAssistant(this.radRichTextBox, assistant);

Implementing a Custom Provider

For any other target element, implement IInlineAssistantInteractionProvider yourself and assign it to InteractionProvider before opening the assistant. This is also useful when you want to customize the built-in behavior, for example by deriving from InlineAIAssistantTextBoxProvider or InlineAIAssistantRadRichTextBoxProvider and overriding one or more of their virtual members, such as GetPosition, to control exactly where the assistant popup opens.

If your target element is a RadRichTextBox, use the built-in InlineAIAssistantRadRichTextBoxProvider described above instead of implementing a custom provider.

The following example implements the interface for the native WPF RichTextBox, which has no built-in provider.

Implementing IInlineAssistantInteractionProvider for a RichTextBox

C#

public class InlineAIAssistantRichTextBoxProvider : IInlineAssistantInteractionProvider
{
    private RichTextBox richTextBox;

    public InlineAIAssistantRichTextBoxProvider(RichTextBox richTextBox)
    {
        this.richTextBox = richTextBox;
    }

    public FrameworkElement TargetElement => this.richTextBox;

    public string FullText => new TextRange(this.richTextBox.Document.ContentStart, this.richTextBox.Document.ContentEnd).Text;

    public string SelectedText => this.richTextBox.Selection.Text;

    public bool CanInsertText(string text)
    {
        return !this.richTextBox.IsReadOnly;
    }

    public bool CanReplaceSelectedText(string text)
    {
        return !this.richTextBox.IsReadOnly && !this.richTextBox.Selection.IsEmpty;
    }

    public void InsertText(string text)
    {
        this.richTextBox.CaretPosition.InsertTextInRun(text);
    }

    public void ReplaceSelectedText(string text)
    {
        this.richTextBox.Selection.Text = text;
    }

    public Point? GetPosition()
    {
        Rect caretRect = this.richTextBox.CaretPosition.GetCharacterRect(LogicalDirection.Forward);
        Rect viewportRect = new Rect(0, 0, this.richTextBox.ActualWidth, this.richTextBox.ActualHeight);

        if (!viewportRect.Contains(caretRect.BottomRight))
        {
            // The caret is scrolled outside of the visible area, so the assistant should not open.
            return null;
        }

        return this.richTextBox.PointToScreen(caretRect.BottomRight);
    }
}

Attaching the custom provider to a RichTextBox

C#

RadInlineAIAssistant assistant = new RadInlineAIAssistant();
assistant.InteractionProvider = new InlineAIAssistantRichTextBoxProvider(this.richTextBox);
assistant.PromptRequest += this.OnPromptRequest;

RadInlineAIAssistant.SetInlineAIAssistant(this.richTextBox, assistant);

See Also

• Getting Started
• Configuring Commands
• Handling Responses