Generate Expressions from Prompts (WPF Report Designer)

• Feb 26, 2026
• 4 minutes to read

Prompt to Expression converts natural language into valid expressions. Instead of writing complex expressions, users describe the desired logic in plain text.

The system sends the prompt to the configured AI service, which generates a valid expression. The Expression Editor or Filter Editor displays the result immediately. If Prompt to Expression fails to create a valid expression, it displays a message that informs the user that a valid expression was not generated.

Run Demo: Prompt to Expression

How It Works

Expression Editor

1. The user opens the Expression Editor, enters a prompt in the Prompt to Expression field, and clicks Send.

   

2. AI generates the expression and the Expression Editor displays the result.

   

Filter Editor

1. The user opens the Filter Editor, enters a prompt in the Prompt to Expression field, and clicks Send.

   

2. AI generates a filter expression and the Filter Editor displays the result.

   

Activate Prompt to Expression

Prerequisites

• .NET 8+ SDK / .NET Framework v4.7.2
• Visual Studio 2022+

Install NuGet Packages

• DevExpress.AIIntegration.Wpf.Reporting
• Microsoft.Extensions.AI (Version=”9.7.1-preview.1.25365.4”)
• Azure.AI.OpenAI (Version=”2.2.0-beta.5”)

This help topic uses Azure OpenAI. See the following help topic for information about NuGet packages required for other supported AI services: AI-powered Extensions.

Note

DevExpress AI-powered extensions follow the “bring your own key” principle. DevExpress does not offer a REST API and does not ship any built-in LLMs/SLMs. You need an active Azure/Open AI subscription to obtain the REST API endpoint, key, and model deployment name. These variables must be specified at application startup to register AI clients and enable DevExpress AI-powered Extensions in your application.

Register AI Client

The following code snippet registers an Azure OpenAI client at application startup:

C#

using Azure.AI.OpenAI;
using DevExpress.AIIntegration;
using Microsoft.Extensions.AI;
using System.ClientModel;

internal static class Program {
    static string AzureOpenAIEndpoint { get { return "AZURE_OPENAI_ENDPOINT"; } }
    static string AzureOpenAIKey { get { return "AZURE_OPENAI_APIKEY"; } }
    static string DeploymentName { get { return "MODEL_NAME"; } } // For example, gpt-5.2.
    [STAThread]
    static void Main(){
        IChatClient client = new AzureOpenAIClient(
            new Uri(AzureOpenAIEndpoint),
            new ApiKeyCredential(AzureOpenAIKey))
                .GetChatClient(DeploymentName).AsIChatClient(); 
        AIExtensionsContainerDesktop.Default.RegisterChatClient(client);
        ApplicationConfiguration.Initialize();
        Application.Run(new Form1());
    }
}

VB.NET

Imports Azure.AI.OpenAI
Imports DevExpress.AIIntegration
Imports Microsoft.Extensions.AI
Imports System.ClientModel

Friend Module Program
    Private ReadOnly Property AzureOpenAIEndpoint() As String
        Get
            Return "AZURE_OPENAI_ENDPOINT"
        End Get
    End Property
    Private ReadOnly Property AzureOpenAIKey() As String
        Get
            Return "AZURE_OPENAI_APIKEY"
        End Get
    End Property
    Private ReadOnly Property DeploymentName() As String
        Get
            Return "MODEL_NAME"
        End Get
    End Property
        <STAThread>
        Sub Main()
        Dim client As IChatClient = (New AzureOpenAIClient(New Uri(AzureOpenAIEndpoint), New ApiKeyCredential(AzureOpenAIKey))).GetChatClient(DeploymentName).AsIChatClient()
        AIExtensionsContainerDesktop.Default.RegisterChatClient(client)
        ApplicationConfiguration.Initialize()
        Application.Run(New Form1())
        End Sub
End Module

Tip

How to Register OpenAI, Azure OpenAI, Ollama, and Semantic Kernel Clients.

Create and Configure Behavior Object

Attach the ReportPromptToExpressionBehavior to the Report Designer to enable AI-powered Prompt-to-Report functionality.

The following properties are available:

ReportPromptToExpressionBehavior.RetryAttemptCount

Specifies the number of additional attempts the AI makes to regenerate an expression if the previous result is invalid.

ReportPromptToExpressionBehavior.PromptAugmentation

Appends additional instructions to each user prompt.

ReportPromptToExpressionBehavior.Temperature

Specifies creativity in AI responses. Set 1 for models (for example, GPT-5, o1, and o3 series) that ignore this parameter to avoid compatibility errors. The default value is 0.

Markup

The following code snippet creates a ReportPromptToExpressionBehavior and configures its Temperature and RetryAttemptCount settings:

XAML

<dx:ThemedWindow
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
    xmlns:dxrud="http://schemas.devexpress.com/winfx/2008/xaml/reports/userdesigner"
    xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm" 
    xmlns:dxai="http://schemas.devexpress.com/winfx/2008/xaml/ai"
    x:Class="DXWPFReportApp.MainWindow"
    Title="Report Designer" Height="800" Width="1000">
    <Grid>
        <dxrud:ReportDesigner x:Name="reportDesigner" Height="NaN" Width="NaN">
            <dxmvvm:Interaction.Behaviors>
                <dxai:ReportPromptToExpressionBehavior x:Name="promptToExpressionBehavior" RetryAttemptCount="3" Temperature="1"/>
            </dxmvvm:Interaction.Behaviors>
        </dxrud:ReportDesigner>
    </Grid>
</dx:ThemedWindow>

Runtime

The following code snippet registers a ReportPromptToExpressionBehavior and attaches it to the WPF Report Designer (reportDesigner):

C#

using DevExpress.Xpf.Core;
using DevExpress.Mvvm.UI.Interactivity;
using DevExpress.AIIntegration.Wpf.Reporting;

namespace WPFReportApp {
    public partial class MainWindow : ThemedWindow {
        public MainWindow() {
            InitializeComponent();
            var promptToExpressionBehavior = new ReportPromptToExpressionBehavior() {
                RetryAttemptCount = 3,
                Temperature = 1
            };
            var behaviors = Interaction.GetBehaviors(reportDesigner);
            behaviors.Add(promptToExpressionBehavior);
            reportDesigner.OpenDocument(new Report1());
        }
    }
}

VB.NET

Imports DevExpress.Xpf.Core
Imports DevExpress.Mvvm.UI.Interactivity
Imports DevExpress.AIIntegration.Wpf.Reporting

Namespace WPFReportApp
    Partial Public Class MainWindow
        Inherits ThemedWindow

        Public Sub New()
            InitializeComponent()
            Dim promptToExpressionBehavior = New ReportPromptToExpressionBehavior() With {
                .RetryAttemptCount = 3,
                .Temperature = 0
            }
            Dim behaviors = Interaction.GetBehaviors(reportDesigner)
            behaviors.Add(promptToExpressionBehavior)
            reportDesigner.OpenDocument(New Report1())
        End Sub
    End Class
End Namespace