Develop Reference

How to fix message boxes appearing behind splash screen?

My WinForms app's main window is slow to load (up to 20 seconds, depending on arguments), so it needs a splash screen.
The main window constructor is slow because it exercises thousands of lines of code (some of it beyond my influence). Sometimes this code pops up message boxes.
I've tried two splash screen designs, they each have problems. Any better ideas?
Splash screen with BackgroundWorker
static void Main(string[] args)
{
var splash = !args.Contains("--no-splash");
if (splash)
{
var bw = new BackgroundWorker();
bw.DoWork += (sender, eventArgs) => ShowSplash();
bw.RunWorkerAsync();
}
var app = new FormMain(args); // slow. sometimes opens blocking message boxes.
Application.Run(app);
}
private static void ShowSplash()
{
using (var splash = new FormSplash())
{
splash.Show();
splash.Refresh();
Thread.Sleep(TimeSpan.FromSeconds(2));
}
}
Problems:
Splash screen sometimes expires before main window open (user thinks app has crashed)
Main window sometimes minimises when splash closes.
Splash screen with WindowsFormsApplicationBase
sealed class App : WindowsFormsApplicationBase
{
protected override void OnCreateSplashScreen()
{
this.SplashScreen = new FormSplash();
}
protected override void OnCreateMainForm()
{
// slow. sometimes opens blocking message boxes.
this.MainForm = new FormMain(this.CommandLineArgs);
}
}
Problems:
Any MessageBoxes opened appear behind splash screen, silently. User won't notice it and thinks app is stuck.
If splash screen is 'always on top', the message box is inaccessible and unclickable.

I agree with Hans Passant in that the code needs to be re-evaluated as the design seems incorrect.
As for the problem at hand, you should be able to resolve this by creating your own instance of a messageBox.
I tested using this code;
public DialogResult TopMostMessageBox(string message, string title, MessageBoxButtons button, MessageBoxIcon icon)
{
return DisplayMessageBox(message, title, button, icon);
}
public DialogResult DisplayMessageBox(string message, string title, MessageBoxButtons buttons, MessageBoxIcon icon)
{
DialogResult result;
using (var topmostForm = new Form {Size = new System.Drawing.Size(1, 1), StartPosition = FormStartPosition.Manual})
{
var rect = SystemInformation.VirtualScreen;
topmostForm.Location = new System.Drawing.Point(rect.Bottom + 10, rect.Right + 10);
topmostForm.Show();
topmostForm.Focus();
topmostForm.BringToFront();
topmostForm.TopMost = true;
result = MessageBox.Show(topmostForm, message, title, buttons, icon);
topmostForm.Dispose();
}
//You might not need all these properties...
return result;
}
//Usage
TopMostMessageBox("Message","Title" MessageBoxButtons.YesNo, MessageBoxIcon.Question)
Again, I need to stress that I agree that the original code needs to be re-factored and am only providing a possible solution to the question.
Hope this helps?

You can implement our own message box and use TopMost property, with TopMost you will get message in-front of splash screen loader.
More about topmost: http://msdn.microsoft.com/en-us/library/system.windows.forms.form.topmost.aspx

In the end, moved the slow code from the constructor to a handler for the OnShown event.
Used WindowsFormsApplicationBase for splash screen as Hans Passant suggested, carefully checked the remaining constructor code to make sure it'll never open an message boxes.

Splash screen to show up in the middle of application

I have a list of report names displayed as Tree hierarchy in ReportViewer control. When user clicks on a report name, an input form loads, user enters some values and presses OK. At this point, Splash screen should load while the backend process is happening (connecting to DB, retrieving values etc). Once the report is loaded in Reportviewer editor, the splashscreen should close.
So far, I am able to display the splash screen however it gets stuck at that point, the actual report does not load and the splash screen stays on forever.
Is it possible to use splashscreen in the middle of application, not at app launch? If so, how do I continue with loading report?
static class Program
{
[STAThread]
static void Main(string[] args)
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new SnapPlusReports());
//new SplashScreenApp().Run(args);
}
}
public class SplashScreenApp : WindowsFormsApplicationBase
{
private static SplashScreenApp _application;
public static void Run(Form form)
{
_application = new SplashScreenApp { MainForm = form };
_application.Run(Environment.GetCommandLineArgs());
}
protected override void OnCreateSplashScreen()
{
this.SplashScreen = new ShowProgress();
base.OnCreateSplashScreen();
}
}

I have done this before by making a new form at run time dynamically with code. Make sure you set all the options up, especially FormBorderStyle to none, or something like that so the user can't close it. Then simply manipulate labels that appear on that form, and eventually close it once your process is complete.
This way you don't have to worry about threading and a nice side effect is that the initial form won't be clickable.
For example I have an about form that pops up during run time (granted I don't change anything on it but the idea is there:
AboutForm aboutForm = new AboutForm();
aboutForm.StartPosition = FormStartPosition.CenterParent;
Label lblAbout = new Label();
Version applicationVersion = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version;
lblAbout.Text = applicationVersion.ToString();
lblAbout.Location = new Point(145,104);
aboutForm.Controls.Add(lblAbout);
aboutForm.ShowDialog();
This shows the current programs version number, etc. There are other labels that already exist on the form (I created it visually first and then called an instance of it).
Hope this helps!

...Catch other instances and gracefully exit if you need only one copy of your app in memory at a given time
static void Main()
{
Application.EnableVisualStyles();
bool exclusive;
System.Threading.Mutex appMutex = new System.Threading.Mutex(true, "MY_APP", out exclusive);
if (!exclusive)
{
MessageBox.Show("Another instance of xxxx xxxBuilder is already running.","MY_APP",
MessageBoxButtons.OK,
MessageBoxIcon.Exclamation );
return;
}
Application.SetCompatibleTextRenderingDefault(false);
xxxWindowsApplication.InitializeApplication();
Application.Run(new frmMenuBuilderMain());
GC.KeepAlive(appMutex);
}
In the main form load you could do something like:
private void frmMenuBuilderMain_Load(object sender, EventArgs e)
{
//Show Splash with timeout Here--
if(!SystemLogin.PerformLogin())
{
this.Close();
return;
}
tmrLoad.Enabled = true;
}

Displaying a "User control is loading" message while loading a User Control

I have a Winforms Application with a TabStrip Control. During runtime, UserControls are to be loaded into different tabs dynamically.
I want to present a "User Control xyz is loading" message to the user (setting an existing label to visible and changing its text) before the UserControl is loaded and until the loading is completely finished.
My approaches so far:
Trying to load the User Control in a BackgroundWorker thread. This fails, because I have to access Gui-Controls during the load of the UserControl
Trying to show the message in a BackgroundWorker thread. This obviously fails because the BackgroundWorker thread is not the UI thread ;-)
Show the Message, call DoEvents(), load the UserControl. This leads to different behaviour (flickering, ...) everytime I load a UserControl, and I can not control when and how to set it to invisible again.
To sum it up, I have two questions:
How to ensure the message is visible directly, before loading the User control
How to ensure the message is set to invisible again, just in the moment the UserControl is completely loaded (including all DataBindings, grid formattings, etc.)

what we use is similar to this:
create a new form that has whatever you want to show the user,
implement a static method where you can call this form to be created inside itself, to prevent memory leaks
create a new thread within this form so that form is running in a seperated thread and stays responsive; we use an ajax control that shows a progress bar filling up.
within the method you use to start the thread set its properties to topmost true to ensure it stays on top.
for instance do this in your main form:
loadingForm.ShowLoadingScreen("usercontrollname");
//do something
loadingform.CloseLoadingScreen();
in the loading form class;
public LoadingScreen()
{
InitializeComponent();
}
public static void ShowLoadingScreen(string usercontrollname)
{
// do something with the usercontroll name if desired
if (_LoadingScreenThread == null)
{
_LoadingScreenThread = new Thread(new ThreadStart(DoShowLoadingScreen));
_LoadingScreenThread.IsBackground = true;
_LoadingScreenThread.Start();
}
}
public static void CloseLoadingScreen()
{
if (_ls.InvokeRequired)
{
_ls.Invoke(new MethodInvoker(CloseLoadingScreen));
}
else
{
Application.ExitThread();
_ls.Dispose();
_LoadingScreenThread = null;
}
}
private static void DoShowLoadingScreen()
{
_ls = new LoadingScreen();
_ls.FormBorderStyle = FormBorderStyle.None;
_ls.MinimizeBox = false;
_ls.ControlBox = false;
_ls.MaximizeBox = false;
_ls.TopMost = true;
_ls.StartPosition = FormStartPosition.CenterScreen;
Application.Run(_ls);
}

Try again your second approach:
Trying to show the message in a BackgroundWorker thread. This obviously fails because the BackgroundWorker thread is not the UI thread ;-)
But this time, use the following code in your background thread in order to update your label:
label.Invoke((MethodInvoker) delegate {
label.Text = "User Control xyz is loading";
label.Visible = true;
});
// Load your user control
// ...
label.Invoke((MethodInvoker) delegate {
label.Visible = false;
});
Invoke allows you to update your UI in another thread.

Working from #wterbeek's example, I modified the class for my own purposes:
center it over the loading form
modification of its opacity
sizing it to the parent size
show it as a dialog and block all user interaction
I was required to show a throbber
I received a null error on line:
if (_ls.InvokeRequired)
so I added a _shown condition (if the action completes so fast that the _LoadingScreenThread thread is not even run) to check if the form exists or not.
Also, if the _LoadingScreenThread is not started, Application.Exit will close the main thread.
I thought to post it for it may help someone else. Comments in the code will explain more.
public partial class LoadingScreen : Form {
private static Thread _LoadingScreenThread;
private static LoadingScreen _ls;
//condition required to check if the form has been loaded
private static bool _shown = false;
private static Form _parent;
public LoadingScreen() {
InitializeComponent();
}
//added the parent to the initializer
//CHECKS FOR NULL HAVE NOT BEEN IMPLEMENTED
public static void ShowLoadingScreen(string usercontrollname, Form parent) {
// do something with the usercontroll name if desired
_parent = parent;
if (_LoadingScreenThread == null) {
_LoadingScreenThread = new Thread(new ThreadStart(DoShowLoadingScreen));
_LoadingScreenThread.SetApartmentState(ApartmentState.STA);
_LoadingScreenThread.IsBackground = true;
_LoadingScreenThread.Start();
}
}
public static void CloseLoadingScreen() {
//if the operation is too short, the _ls is not correctly initialized and it throws
//a null error
if (_ls!=null && _ls.InvokeRequired) {
_ls.Invoke(new MethodInvoker(CloseLoadingScreen));
} else {
if (_shown)
{
//if the operation is too short and the thread is not started
//this would close the main thread
_shown = false;
Application.ExitThread();
}
if (_LoadingScreenThread != null)
_LoadingScreenThread.Interrupt();
//this check prevents the appearance of the loader
//or its closing/disposing if shown
//have not found the answer
//if (_ls !=null)
//{
_ls.Close();
_ls.Dispose();
//}
_LoadingScreenThread = null;
}
}
private static void DoShowLoadingScreen() {
_ls = new LoadingScreen();
_ls.FormBorderStyle = FormBorderStyle.None;
_ls.MinimizeBox = false;
_ls.ControlBox = false;
_ls.MaximizeBox = false;
_ls.TopMost = true;
//get the parent size
_ls.Size = _parent.Size;
//get the location of the parent in order to show the form over the
//target form
_ls.Location = _parent.Location;
//in order to use the size and the location specified above
//we need to set the start position to "Manual"
_ls.StartPosition =FormStartPosition.Manual;
//set the opacity
_ls.Opacity = 0.5;
_shown = true;
//Replaced Application.Run with ShowDialog to show as dialog
//Application.Run(_ls);
_ls.ShowDialog();
}
}

Delaying Window for Splash Screen

I am developing a project and I want to add to it a splash screen. I have checked questions here on Stackoverflow and other blogs and MSDN etc. but could not find the solution I am looking for.
I want my SplashScreen,
1- appear and stay on the screen 3-4 seconds but at the same time I want my Main Window NOT TO appear. When my splash screen fades out completely then Main Window should appear. Many of the examples I have checked out do not implement this. Even though I set SplashScreen.Close.(TimeSpan.FromMiliseconds(4000)) MainWindow still apeear immediately front or back of SplashScreen. They say "add an image to your project, make it's Build Action SplashScreen or Resource, if you want to handle fade out time go App.xaml.cs file and implement your own Main() method and put your logic." I know that already. It does not work.
2- If possible I want my splashscreen NOT TO fade out slowly. I want it to disappear suddenly.(if this is not possible or really hard for a intermediate developer to do it, it is ok. you may disregard.)
And please I want C# code not Xaml. My project is based on WPF adn .NET 4.0 client profile.
Thank you.

Why don't you make your splash screen a fully qualified XAML <window> and in your App.xaml set it up as your StartupUri:
<Application x:Class="MyApp.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="SplashWindow.xaml">
Then in your splash window's Load Event you initialize the main window (preferably somewhere else so the instance sticks around when you close the splash). From here you can also specify a timer for x-seconds to go off and show the main window / hide the splash window.
using System.Threading;
/// -------------------------------
private Timer t;
private void Window_Loaded(object sender, RoutedEventArgs e)
{
App.MainWindow = new MainWindow(); // Creates but wont show
t = new Timer(new TimerCallback(CloseSplash), null, new TimeSpan(0,0,10), new TimeSpan(0,0,0,0,-1));
// Do Other load stuff here?
}
private void CloseSplash(object info)
{
// Dispatch to UI Thread
Dispatcher.Invoke(DispatcherPriority.Normal, x => CloseSplashMain());
}
private void CloseSplashMain()
{
App.MainWindow.Show()
this.Close();
}
You'll have to change your app's main window behaviour though, otherwise closing the splash window will cause the app to close.
public partial class App : Application
{
private void Application_Startup(object sender, StartupEventArgs e)
{
App.Current.ShutdownMode = ShutdownMode.OnLastWindowClose;
}
}
Also don't forget to dispose your timer when you're done. It's an IDisposable and will keep firing that method unless it's stopped.

There are answers but I find a an easier one. Just use the Thread.Sleep(int miliSeconds) method in the main window's constructor. This will delay your app in order to open specified miliseconds later.

In the constructor of App.xaml.cs open your splash screen, wait for a few seconds, then close before proceeding with rest of the app. I am using Unity, so I close the splash screen somewhere after the Boostrapper has initialized some services.
public partial class App : Application
{
private static SplashScreen _splashScreen;
public App()
{
OpenSplashScreen();
new Bootstrapper().Run();
}
private void OpenSplashScreen()
{
_splashScreen = new SplashScreen("SplashScreen/splash.jpg");
_splashScreen.Show(false);
}
internal static void CloseSplashScreen(double time)
{
_splashScreen.Close(TimeSpan.FromSeconds(0));
_splashScreen = null;
}
}
where Bootstrapper.cs is listed below:
public class Bootstrapper : UnityBootstrapper
{
protected override void ConfigureContainer()
{
base.ConfigureContainer();
var section = (UnityConfigurationSection)ConfigurationManager.GetSection("unity");
section.Configure(Container);
// initialize some services before
App.CloseSplashScreen(0);
}
protected override IModuleEnumerator GetModuleEnumerator()
{
return new ExtendedConfigurationModuleEnumerator();
}
protected override DependencyObject CreateShell()
{
MainWindow shell = new MainWindow(Container);
shell.Show();
return shell;
}
}

The best way and using the API is
SplashScreen splash = new SplashScreen("splashscreen.jpg");
splash.Show(false);
splash.Close(TimeSpan.FromMilliseconds(2));
InitializeComponent();

Any way to create a hidden main window in C#?

I just want a c# application with a hidden main window that will process and respond to window messages.
I can create a form without showing it, and can then call Application.Run() without passing in a form, but how can I hook the created form into the message loop?
Is there another way to go about this?
Thanks in advance for any tips!

Excellent! That link pointed me in the right direction. This seems to work:
Form f = new Form1();
f.FormBorderStyle = FormBorderStyle.FixedToolWindow;
f.ShowInTaskbar = false;
f.StartPosition = FormStartPosition.Manual;
f.Location = new System.Drawing.Point(-2000, -2000);
f.Size = new System.Drawing.Size(1, 1);
Application.Run(f);
To keep it from showing up in Alt-Tab, you need it to be a tool window. Unfortunately, this prevents it from starting minimized. But setting the start position to Manual and positioning it offscreen does the trick!

In the process of re-writing a VC++ TaskTray App, in C# .NET, I found the following method truly workable to achieve the following.
No initial form dislayed at startup
Running Message Loop that can be used with Invoke/BeginInvoke as needed as IsWindowHandle is true
The steps I followed:
Used an ApplicationContext in Application.Run() Instead of a form. See http://www.codeproject.com/Articles/18683/Creating-a-Tasktray-Application for the example I used.
Set the Form's ShowInTaskbar property to true within the GUI Designer. (This seems counter productive but it works)
Override the OnLoad() method in your Form Class setting Visible and ShowInTaskbar to false as shown below.
protected override void OnLoad(EventArgs e)
{
Visible = false;
ShowInTaskbar = false;
base.OnLoad(e);
}

I know this is old question, but it ranks well in google, so I will provide my solution anyway.
I do two things:
private void Form_Load(object sender, EventArgs e)
{
Opacity = 0;
}
private void Form_Shown(object sender, EventArgs e)
{
Visible = false;
Opacity = 100;
}

The best way is to use the following 1-2 lines in the constuctor:
this.WindowState = FormWindowState.Minimized;
this.ShowInTaskbar = false; // This is optional
You can even set the Minimized property in the VS Property window.

You can create a class that inherits from System.Windows.Forms.NativeWindow (which provides basic message loop capability) and reference the Handle property in its constructor to create its handle and hook it into the message loop. Once you call Application.Run, you will be able to process messages from it.

I solved the problem like this:
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Main main = new Main();
Application.Run();
//Application.Run(new Main());
}
This code resides in the Program.cs file, and you can see the original Application.Run method call commented out. I just create a Main class object (my main form class is named Main) and start application message loop w/o any parameters. This starts the application, initializes any form components but doesn't show the form.
Note: you have to have some method to get your window showing (like system tray icon, hotkey or timer or anything you might like).

public partial class Form1 : Form
{
private bool _isApplicationRun;
public Form1(bool applicationRun)
{
InitializeComponent();
_isApplicationRun = applicationRun;
}
protected override void SetVisibleCore(bool value)
{
if (_isApplicationRun)
{
_isApplicationRun = false;
base.SetVisibleCore(false);
return;
}
base.SetVisibleCore(value);
}
}
static class Program
{
[STAThread]
static void Main()
{
Application.Run(new Form1(true));
}
}

Why can't you just pass the form when you call Application.Run? Given that it's clearly a blocking call, on what event do you want to show the form? Just calling form.Show() should be enough.

Using Kami's answer as an inspiration, I created a more complete concept. If you use this solution, don't ever show the hidden window. If you do, the user might close it and then you've lost the ability to control the application exit in an orderly way. This approach can be used to manage a Timer, NotifyIcon, or any other component that is happy living on an invisible form.
using System;
using System.Windows.Forms;
namespace SimpleHiddenWinform
{
internal class HiddenForm : Form
{
private Timer _timer;
private ApplicationContext _ctx;
public HiddenForm(ApplicationContext ctx)
{
_ctx = ctx;
_timer = new Timer()
{
Interval = 5000, //5 second delay
Enabled = true
};
_timer.Tick += new EventHandler(_timer_Tick);
}
void _timer_Tick(object sender, EventArgs e)
{
//tell the main message loop to quit
_ctx.ExitThread();
}
}
static class Program
{
[STAThread]
static void Main()
{
var ctx = new ApplicationContext();
var frmHidden = new HiddenForm(ctx);
//pass the application context, not the form
Application.Run(ctx);
}
}
}

Form1 f1=new Form1();
f1.WindowState = FormWindowState.Minimized;
f1.ShowInTaskbar = false;

in the Form1 code file add this.Visible = false; to the constructor.
This will hide the window but it will flash for a sec before it is hidden. Alternatively you can write your own Application.Run command.
for more info http://social.msdn.microsoft.com/forums/en-US/winforms/thread/dece45c8-9076-497e-9414-8cd9b34f572f/
also you may want to set the this.ShowInTaskbar to false.

You should look at creating a 'service' as this is an application without a form.
See http://support.microsoft.com/kb/816169