Devexpress Winforms Loading Indicators

DevExpress WinForms Loading Indicators

DevExpress.XtraSplashScreen.SplashScreenManager is the single static component that manages all loading indicator types in DevExpress WinForms. It provides four distinct indicator categories suited to different scenarios: a Splash Screen shown at app startup, a Wait Form that blocks the whole window during operations, an Overlay Form that blocks a specific panel or control (the WinForms equivalent of the WPF LoadingDecorator), and a ProgressPanel control for inline non-blocking feedback.

All types run in a separate thread (except ProgressPanel, which is a plain control) so they stay animated while your main thread performs work.

When to Use This Skill

• Choosing between the four indicator types for a given scenario.
• Showing a splash screen before the main form loads (ShowFluentSplashScreen / ShowForm).
• Showing a Wait Form during a long operation and updating its caption/description dynamically.
• Overlaying a specific control or form with a semi-transparent spinner (Overlay Form / Loading Decorator pattern).
• Dropping a ProgressPanel onto a form for inline progress feedback.
• Implementing try/finally patterns to guarantee overlays are always closed.
• Customizing the Overlay Form with a custom painter (OverlayWindowPainterBase).

Prerequisites & Installation

NuGet Package

Assembly and Namespaces

using DevExpress.XtraSplashScreen;   // SplashScreenManager, IOverlaySplashScreenHandle
using DevExpress.XtraWaitForm;        // WaitForm base class, ProgressPanel

Assembly: DevExpress.XtraEditors.v26.1.dll

Host Form

Always use XtraForm or RibbonForm — never a plain Form. This ensures skin propagation works correctly for Wait Forms and Overlay Forms.

Before You Start — Ask the Developer

If the host agent has a structured question-asking tool available, use it to ask these questions one at a time with clear options — for example, Claude Code's AskUserQuestion tool or GitHub Copilot's askQuestions tool. If no such tool is available, ask the questions directly in the chat response before generating code.

1. When does the indicator appear — at app startup, or during a runtime operation triggered by a button/event?
2. What should be blocked — the entire form, one panel/control, or nothing (just visual feedback)?
3. Does the user need to see progress text that updates during the operation (e.g., "Row 42 of 1000")?
4. Can the user cancel the operation?
5. Is async/await used, or is the work done on a background thread? (Both work; async is the recommended pattern.)

Documentation & Navigation Guide

Getting Started (NuGet, Setup, Minimal Code)

Refer to references/getting-started.md (.NET 8+) or references/getting-started-dotnet-fw.md (.NET Framework 4.x) When you need to: install the NuGet package, know which assembly/namespace to reference, or see the minimum code to show any of the four indicator types.

Indicator Types — Comparison and API Patterns

Refer to references/indicators-comparison.md When you need to: choose between Splash Screen, Wait Form, Overlay Form, and ProgressPanel; understand API patterns in depth; customize the Overlay Form with a custom painter; send custom data to a Wait Form via SendCommand; understand the "Loading Decorator" → Overlay Form mapping from WPF.

Quick Start: Most Common Case

Overlay Form over a grid while data loads:

private async void btnRefresh_Click(object sender, EventArgs e)
{
    IOverlaySplashScreenHandle handle = SplashScreenManager.ShowOverlayForm(gridControl1);
    try {
        await LoadDataAsync();
    }
    finally {
        SplashScreenManager.CloseOverlayForm(handle);
    }
}

Wait Form for a long background task:

// requires SplashScreenManager component + generated WaitForm1
splashScreenManager1.ShowWaitForm();
try {
    splashScreenManager1.SetWaitFormCaption("Exporting...");
    await ExportAsync();
}
finally {
    splashScreenManager1.CloseWaitForm();
}

Fluent Splash Screen at app startup (Program.cs + MainForm):

// Program.cs — shown before the message loop starts
SplashScreenManager.ShowFluentSplashScreen(
    title:   "My App",
    subtitle: "Loading...",
    loadingIndicatorType: FluentLoadingIndicatorType.Dots
);
Application.Run(new MainForm());

The splash runs on its own thread, so you must close it explicitly once the main form is ready — otherwise it can keep the app alive on exit (see Troubleshooting). Close it from the main form, e.g. in OnShown:

// MainForm.cs
protected override void OnShown(EventArgs e) {
    base.OnShown(e);
    SplashScreenManager.CloseForm();   // close the startup splash once the form is visible
}

Key API Reference

SplashScreenManager (static)

ShowOverlayForm — pick one signature (do not mix)

There are distinct overloads; choose one and use only its parameters. Do not combine the OverlayWindowOptions object with the individual named parameters in the same call (e.g. ShowOverlayForm(control, options, startupDelay: 300) does not compile).

// 1) Simplest — overlay over a control with defaults
var h = SplashScreenManager.ShowOverlayForm(gridControl1);

// 2) With an options object (configure once, pass it alone)
var options = new OverlayWindowOptions(backColor: Color.Black, opacity: 0.5);
var h = SplashScreenManager.ShowOverlayForm(gridControl1, options);

// 3) The multi-parameter named overload (no options object)
var h = SplashScreenManager.ShowOverlayForm(
    owner: gridControl1, startupDelay: 300, opacity: 128, fadeIn: true, fadeOut: true);

Note the two different opacity scales: on the multi-parameter ShowOverlayForm overload opacity is an int? (0–255), while OverlayWindowOptions(opacity: …) takes a double (0.0–1.0). imageSize (in the multi-parameter overload) is a Size? — pass new Size(w, h), not a made-up ImageSize.Default.

SplashScreenManager (instance — from designer component)

ProgressPanel

Two similar animation enums — don't confuse them. ProgressPanel.WaitAnimationType is a WaitingAnimatorType (Default/Line/Ring/Bar). The Overlay Form's animationType parameter is a different enum, DevExpress.XtraSplashScreen.WaitAnimationType, which only has Image and Line — there is no WaitAnimationType.Ring for the overlay.

Troubleshooting

Constraints & Important Notes

• "Loading Decorator" in WinForms — there is no LoadingDecorator class in WinForms (it exists in WPF). Use the Overlay Form (SplashScreenManager.ShowOverlayForm) for the same effect.
• ProgressPanel is main-thread only — it does not run in a separate thread. It stays animated only if the UI message loop is not blocked (use async/await).
• Wait Form must be created by SplashScreenManager — you cannot new WaitForm1() and show it like a regular form; the manager sets it up in a separate thread.
• Never update Wait Form controls directly from the main thread — use SendCommand / ProcessCommand for anything beyond SetWaitFormCaption / SetWaitFormDescription.
• Overlay Form requires an initialized control handle — ShowOverlayForm before Form.Load throws InvalidOperationException.
• Never generate skin / look-and-feel code for a loading indicator — do not add BonusSkins.Register(), UserLookAndFeel.Default.SetSkinStyle(...), WindowsFormsSettings.LoadApplicationSettings(), or SkinManager calls. The indicators inherit the application's existing skin; skin setup is the application's responsibility and is out of scope here.
• Never wait with Application.DoEvents() — do not write a while (!done) Application.DoEvents(); busy-loop to keep an indicator responsive. Use async/await (and Task.Run for CPU-bound work) so the UI message loop keeps running; the indicator animates on its own.
• Adding assembly references (.NET Framework): Resolve the required assemblies via the DevExpress Docs MCP and add the corresponding NuGet package. Avoid manually editing the .csproj references node to add new assembly references.

Using DevExpress Documentation MCP

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• Search: devexpress_docs_search(technologies=["WindowsForms"], question="<keywords>")
• Fetch: devexpress_docs_get_content(url="<url-from-search>")

Use MCP for: the full ShowOverlayForm / ShowFluentSplashScreen overload surfaces, OverlayWindowOptions / FluentSplashScreenOptions members, custom painters (OverlayWindowPainterBase), Wait Form cancellation with CancellationTokenSource, and SendCommand / ProcessCommand for passing custom data to a Wait Form.

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