Prompt to Expression

• Mar 25, 2026
• 4 minutes to read

Prompt to Expression converts natural language into valid filter and column expressions for data-aware WPF controls. Users describe the desired behavior using their natural language instead of writing complex expressions:

Sample Filter Expression

Display delayed shipments

Sample Column Expression

Display total cost

The system sends the prompt to the configured AI service that generates a valid expression for the control. The Expression Editor or Filter Editor displays and validates the result immediately.

Run Demo: Prompt to Expression

Supported Controls

• GridControl (Expression Editor and Filter Editor)
• TreeListControl (Expression Editor and Filter Editor)
• ExpressionEditorControl (standalone Expression Editor)
• FilterEditorControl (standalone Filter Editor)

Note

• Prompt to Expression works at runtime only.
• Legacy Expression and Filter Editors are not supported.

Use AI-powered Expressions

Filter Editor

1. Opens the Filter Editor.

   

2. Input intent in the Prompt to Expression field using natural language and click Send.

   

3. AI generates a filter expression. The Filter Editor displays the result.

   

Expression Editor

1. Open the Expression Editor for an unbound column.

   

2. Input an intent in the Prompt to Expression field using a natural language and click Send.

   

3. AI generates the expression. The Expression Editor displays the result.

   

Activate Prompt to Expression

Prerequisites

.NET 8 SDK / .NET Framework v4.7.2

Install DevExpress NuGet Packages

1. DevExpress.AIIntegration.Wpf
2. DevExpress.Mvvm.UI
3. DevExpress.Mvvm.UI.Interactivity

Register AI Client

See the following help topic for information on required NuGet packages and system requirements: Register an AI Client.

The following code snippet registers an Azure OpenAI client at application startup within the AIExtensionsContainerDesktop container:

C#

using Azure.AI.OpenAI;
using DevExpress.AIIntegration;
using DevExpress.Xpf.Core;
using Microsoft.Extensions.AI;
using System;
using System.Windows;

namespace AIAssistantApp {
    public partial class App : Application {
        static App() {
            CompatibilitySettings.UseLightweightThemes = true;
        }

        protected override void OnStartup(StartupEventArgs e) {
            base.OnStartup(e);
            ApplicationThemeHelper.ApplicationThemeName = "Win11Light";

            // For example, ModelId = "gpt-4o-mini"
            IChatClient azureChatClient = new Azure.AI.OpenAI.AzureOpenAIClient(new Uri(AzureOpenAIEndpoint),
                new System.ClientModel.ApiKeyCredential(AzureOpenAIKey)).GetChatClient(ModelId).AsIChatClient();
            AIExtensionsContainerDesktop.Default.RegisterChatClient(azureChatClient);
        }
    }
}

VB.NET

Imports Azure.AI.OpenAI
Imports DevExpress.AIIntegration
Imports DevExpress.Xpf.Core
Imports Microsoft.Extensions.AI
Imports System
Imports System.Windows

Namespace AIAssistantApp
    Partial Public Class App
        Inherits Application

        Shared Sub New()
            CompatibilitySettings.UseLightweightThemes = True
        End Sub

        Protected Overrides Sub OnStartup(ByVal e As StartupEventArgs)
            MyBase.OnStartup(e)
            ApplicationThemeHelper.ApplicationThemeName = "Win11Light"

            ' For example, ModelId = "gpt-4o-mini"
            Dim azureChatClient As IChatClient = New AzureOpenAIClient(New Uri(AzureOpenAIEndpoint), 
                New System.ClientModel.ApiKeyCredential(AzureOpenAIKey)).GetChatClient(ModelId).AsIChatClient()
            AIExtensionsContainerDesktop.Default.RegisterChatClient(azureChatClient)
        End Sub
    End Class
End Namespace

Attach Prompt to Expression Behavior

Attach PromptToExpressionBehavior to a supported control in XAML or in code.

XAML

<ThemedWindow xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
              xmlns:dxai="http://schemas.devexpress.com/winfx/2008/xaml/ai"
              xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm">
    <dxg:GridControl ItemsSource="{Binding Employees}">
        <dxmvvm:Interaction.Behaviors>
            <dxai:PromptToExpressionBehavior
                RetryAttemptCount="3"
                Temperature="0.3"
                AugmentWithFunctionInfo="True" />
        </dxmvvm:Interaction.Behaviors>
        <dxg:GridControl.View>
            <dxg:TableView />
        </dxg:GridControl.View>
    </dxg:GridControl>
</ThemedWindow>

---

Code-Behind

using DevExpress.AIIntegration.Wpf;
using DevExpress.Mvvm.UI.Interactivity;

var behavior = new PromptToExpressionBehavior {
    RetryAttemptCount = 3,
    Temperature = 0.3f,
    AugmentWithFunctionInfo = true
};
Interaction.GetBehaviors(gridControl).Add(behavior);

Behavior Properties

RetryAttemptCount

Gets or sets the number of subsequent attempts to generate a valid expression using the AI service after the initial failure. This is a dependency property.

Temperature

Gets or sets the balance between creativity and consistency in AI responses. This is a dependency property.

PromptAugmentation

Gets or sets additional instructions that modify the prompt before processing. This is a dependency property.

AugmentWithFunctionInfo

Gets or sets whether to inject information about supported functions and operators into each user prompt. This is a dependency property.

EnableInExpressionEditor

Gets or sets whether to display the AI prompt control in the Expression Editor. This is a dependency property.

EnableInFilterEditor

Gets or sets whether to display the AI prompt control in the Filter Editor. This is a dependency property.

Keyboard Navigation

Use the following keystrokes to interact with the Prompt to Expression interface:

Key	Action
Enter	Moves the caret to the next line.
Ctrl + Enter	Sends a prompt to the AI service.
Esc	Cancels a request.

Specific Notes

Runtime Scope

Design-time Filter Editor and Expression Editor are not supported.

Retry Policy

Use RetryAttemptCount to specify the number of subsequent attempts to generate an expression after the initial failure.

Error Handling

Expression Editor and Filter Editor validate generated expressions and display an error message when all attempts to generate a valid expression failed.