I am trying to start a winForm from a thread, but when i do so, the form show but none of the labels are loaded ( the background where they should be is white ) and the form is frozen.
I've tried it with some other winForms that i know that work just fine and it still doesn't seem to work ? Has anyone encountered this problem ?
I know the question is vague but there isn't really any specific code that I could give to help understand the problem.
That is because the Message Loop runs on UI thread only. And when a control or window is created in any other thread, it cannot access that message loop. And thus, cannot process user input.
To solve this, try creating a window from UI thread and create a thread from that window to do whatever you want to do in different thread.
UI thread is supposed to be one.
Then, I suggest you to open your form calling a method of your original form thread, like in the example below:
(To test it just create an empty form called MainForm and paste this code in it)
public delegate void OpenFormDelegate(string txt);
public partial class MainForm : Form
{
public MainForm()
{
InitializeComponent();
var button1 = new Button();
button1.Text = "Run for 5 secs and open new window";
button1.Dock = DockStyle.Top;
this.Controls.Add(button1);
button1.Click += new EventHandler(button1_Click);
}
private void button1_Click(object sender, EventArgs e)
{
Thread t = new Thread(new ThreadStart(Run));
t.Start();
}
public void Run()
{
Thread.Sleep(5000); // sleep for 5 seconds
this.BeginInvoke(new OpenFormDelegate(OpenNewForm), "Hello World !");
}
public void OpenNewForm(string text)
{
Form f = new Form();
f.Text = text;
f.Show();
}
}
It is related to thread access, when the new form is created it will not be able to access the UI thread. Use the main thread to create the form and new thread to process the infomation.
I need to show splash screen on my application start for few seconds. Does anybody know how to implement this?
Will be much appreciate for the help.
First, create your splash screen as a borderless, immovable form with your image on it, set to initially display at the center of the screen, colored the way you want. All of this can be set from within the designer; specifically, you want to:
Set the form's ControlBox, MaximizeBox, MinimizeBox and ShowIcon properties to "False"
Set the StartPosition property to "CenterScreen"
Set the FormBorderStyle property to "None"
Set the form's MinimumSize and MaximumSize to be the same as its initial Size.
Then, you need to decide where to show it and where to dismiss it. These two tasks need to occur on opposite sides of the main startup logic of your program. This could be in your application's main() routine, or possibly in your main application form's Load handler; wherever you're creating large expensive objects, reading settings from the hard drive, and generally taking a long time to do stuff behind the scenes before the main application screen displays.
Then, all you have to do is create an instance of your form, Show() it, and keep a reference to it while you do your startup initialization. Once your main form has loaded, Close() it.
If your splash screen will have an animated image on it, the window will need to be "double-buffered" as well, and you will need to be absolutely sure that all initialization logic happens outside the GUI thread (meaning you cannot have your main loading logic in the mainform's Load handler; you'll have to create a BackgroundWorker or some other threaded routine.
Here are some guideline steps...
Create a borderless form (this will be your splash screen)
On application start, start a timer (with a few seconds interval)
Show your Splash Form
On Timer.Tick event, stop timer and close Splash form - then show your main application form
Give this a go and if you get stuck then come back and ask more specific questions relating to your problems
simple and easy solution to create splash screen
open new form use name "SPLASH"
change background image whatever you want
select progress bar
select timer
now set timer tick in timer:
private void timer1_Tick(object sender, EventArgs e)
{
progressBar1.Increment(1);
if (progressBar1.Value == 100) timer1.Stop();
}
add new form use name "FORM-1"and use following command in FORM 1.
note: Splash form works before opening your form1
add this library
using System.Threading;
create function
public void splash()
{
Application.Run(new splash());
}
use following command in initialization like below.
public partial class login : Form
{
public login()
{
Thread t = new Thread(new ThreadStart(splash));
t.Start();
Thread.Sleep(15625);
InitializeComponent();
enter code here
t.Abort();
}
}
http://solutions.musanitech.com/c-create-splash-screen/
I wanted a splash screen that would display until the main program form was ready to be displayed, so timers etc were no use to me. I also wanted to keep it as simple as possible.
My application starts with (abbreviated):
static void Main()
{
Splash frmSplash = new Splash();
frmSplash.Show();
Application.Run(new ReportExplorer(frmSplash));
}
Then, ReportExplorer has the following:
public ReportExplorer(Splash frmSplash)
{
this.frmSplash = frmSplash;
InitializeComponent();
}
Finally, after all the initialisation is complete:
if (frmSplash != null)
{
frmSplash.Close();
frmSplash = null;
}
Maybe I'm missing something, but this seems a lot easier than mucking about with threads and timers.
create splash
private void timer1_Tick(object sender, EventArgs e)
{
counter++;
progressBar1.Value = counter *5;
// label2.Text = (5*counter).ToString();
if (counter ==20)
{
timer1.Stop();
this.Close();
}
}
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.BackColor = System.Drawing.SystemColors.GradientInactiveCaption;
this.ClientSize = new System.Drawing.Size(397, 283);
this.ControlBox = false;
this.Controls.Add(this.label2);
this.Controls.Add(this.progressBar1);
this.Controls.Add(this.label1);
this.ForeColor = System.Drawing.SystemColors.ControlLightLight;
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
this.Name = "Splash";
this.ShowIcon = false;
this.ShowInTaskbar = false;
this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
this.ResumeLayout(false);
this.PerformLayout();
Then in your application
sp = new Splash();
sp.ShowDialog();
The other answers here cover this well, but it is worth knowing that there is built in functionality for splash screens in Visual Studio: If you open the project properties for the windows form app and look at the Application tab, there is a "Splash screen:" option at the bottom. You simply pick which form in your app you want to display as the splash screen and it will take care of showing it when the app starts and hiding it once your main form is displayed.
You still need to set up your form as described above (with the correct borders, positioning, sizing etc.)
None of the other answers gave me exactly what I was looking for. Read on for my solution to the problem.
I want a splash screen to fade in from 0% opacity to 100% opacity while things boot up, with a minimum display time of 2000ms (to allow the full fade in effect to show). Once everything is ready, I want the splash screen to display for a further 500ms while the main screen displays behind the splash screen. Then I want the splash screen to go away, leaving the main screen running.
Note that I use the MVP pattern for winforms. If you don't use MVP, you will need to simplify the below example a little.
Long story short, you need to create an AppContext class that inherits from ApplicationContext. I have put this in my Program.cs as below:
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.SetHighDpiMode(HighDpiMode.SystemAware);
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new AppContext());
}
}
public class AppContext : ApplicationContext
{
private IMainPresenter _mainPresenter;
private bool _ready;
public AppContext()
{
_ready = false;
using (ISplashPresenter splashPresenter = new SplashPresenter(new SplashView()))
{
Stopwatch sw = Stopwatch.StartNew();
_mainPresenter = new MainPresenter(new MainView());
_mainPresenter.Closed += MainPresenter_Closed;
new Thread(() =>
{
// !!! Do work here !!!
if (sw.ElapsedMilliseconds < 2000)
Thread.Sleep(2000 - (int)sw.ElapsedMilliseconds);
_ready = true;
})
.Start();
while (!_ready)
{
Application.DoEvents();
Thread.Sleep(1);
}
_mainPresenter.Show();
_ready = false;
new Thread(() =>
{
Thread.Sleep(500);
_ready = true;
})
.Start();
while (!_ready)
{
Application.DoEvents();
Thread.Sleep(1);
}
}
}
private void MainPresenter_Closed(object sender, EventArgs e)
{
ExitThread();
}
}
There are several implementation specific details that I haven't gone into here, such as ISplashPresenter implementing IDisposable and exactly how the fade in is managed; if enough people request it I will edit this answer to include a complete example.
First you should create a form with or without Border (border-less is preferred for these things)
public class SplashForm : Form
{
Form _Parent;
BackgroundWorker worker;
public SplashForm(Form parent)
{
InitializeComponent();
BackgroundWorker worker = new BackgroundWorker();
this.worker.DoWork += new System.ComponentModel.DoWorkEventHandler(this.worker _DoWork);
backgroundWorker1.RunWorkerAsync();
_Parent = parent;
}
private void worker _DoWork(object sender, DoWorkEventArgs e)
{
Thread.sleep(500);
this.hide();
_Parent.show();
}
}
At Main you should use that
static class Program
{
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new SplashForm());
}
}
Maybe a bit late to answer but i would like to share my way.
I found an easy way with threads in the main program for a winform application.
Lets say you have your form "splashscreen" with an animation, and your "main" which has all your application code.
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Thread mythread;
mythread = new Thread(new ThreadStart(ThreadLoop));
mythread.Start();
Application.Run(new MainForm(mythread));
}
public static void ThreadLoop()
{
Application.Run(new SplashScreenForm());
}
In your main form in the constructor:
public MainForm(Thread splashscreenthread)
{
InitializeComponent();
//add your constructor code
splashscreenthread.Abort();
}
This way the splashscreen will last just the time for your main form to load.
Your splashcreen form should have his own way to animate/display information.
In my project my splashscreen start a new thread, and every x milliseconds it changes his main picture to another which is a slightly different gear, giving the illusion of a rotation.
example of my splashscreen:
int status = 0;
private bool IsRunning = false;
public Form1()
{
InitializeComponent();
StartAnimation();
}
public void StartAnimation()
{
backgroundWorker1.WorkerReportsProgress = false;
backgroundWorker1.WorkerSupportsCancellation = true;
IsRunning = true;
backgroundWorker1.RunWorkerAsync();
}
public void StopAnimation()
{
backgroundWorker1.CancelAsync();
}
delegate void UpdatingThreadAnimation();
public void UpdateAnimationFromThread()
{
try
{
if (label1.InvokeRequired == false)
{
UpdateAnimation();
}
else
{
UpdatingThreadAnimation d = new UpdatingThreadAnimation(UpdateAnimationFromThread);
this.Invoke(d, new object[] { });
}
}
catch(Exception e)
{
}
}
private void UpdateAnimation()
{
if(status ==0)
{
// mypicture.image = image1
}else if(status ==1)
{
// mypicture.image = image2
}
//doing as much as needed
status++;
if(status>1) //change here if you have more image, the idea is to set a cycle of images
{
status = 0;
}
this.Refresh();
}
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
BackgroundWorker worker = sender as BackgroundWorker;
while (IsRunning == true)
{
System.Threading.Thread.Sleep(100);
UpdateAnimationFromThread();
}
}
Hope this will help some people.
Sorry if i have made some mistakes. English is not my first language.
Here is the easiest way of creating a splash screen:
First of all, add the following line of code before the namespace in Form1.cs code:
using System.Threading;
Now, follow the following steps:
Add a new form in you application
Name this new form as FormSplashScreen
In the BackgroundImage property, choose an image from one of your folders
Add a progressBar
In the Dock property, set it as Bottom
In MarksAnimationSpeed property, set as 50
In your main form, named as Form1.cs by default, create the following method:
private void StartSplashScreen()
{
Application.Run(new Forms.FormSplashScreen());
}
In the constructor method of Form1.cs, add the following code:
public Form1()
{
Thread t = new Thread(new ThreadStart(StartSplashScreen));
t.Start();
Thread.Sleep(5000);
InitializeComponent();//This code is automatically generated by Visual Studio
t.Abort();
}
Now, just run the application, it is going to work perfectly.
Here's my 2023 take on a 2011 question.
Over time, I've done this many times in many ways. The approach that currently use:
Force the main form Handle creation so that the message that creates the splash can be posted into the main form's message queue using BeginInvoke. This allows the main form ctor to return. Ordinarily the handle (the native hWnd) doesn't come into existence until it's shown. Therefore, it needs to be coerced while it's still hidden.
Override the SetVisibleCore() preventing the main window from becoming visible until the Splash has finished processing.
public partial class MainForm : Form
{
public MainForm()
{
InitializeComponent();
Debug.Assert(!IsHandleCreated, "Expecting handle is not yet created.");
// Ordinarily we don't get the handle until
// window is shown. But we want it now.
_ = Handle;
Debug.Assert(IsHandleCreated, "Expecting handle exists.");
// Call BeginInvoke on the new handle so as not to block the CTor.
BeginInvoke(new Action(()=> execSplashFlow()));
}
protected override void SetVisibleCore(bool value) =>
base.SetVisibleCore(value && _initialized);
bool _initialized = false;
private void execSplashFlow()
{
using (var splash = new SplashForm())
{
splash.ShowDialog();
}
_initialized= true;
WindowState = FormWindowState.Maximized;
Show();
}
}
Splash Example
The async initialization can be performed in the Splash class itself or it can fire events causing the main app to do things. Either way, when it closes itself the main form will set the _initialized bool to true and it is now capable of becoming visible.
public partial class SplashForm : Form
{
public SplashForm()
{
InitializeComponent();
StartPosition = FormStartPosition.CenterScreen;
FormBorderStyle = FormBorderStyle.None;
}
protected async override void OnVisibleChanged(EventArgs e)
{
base.OnVisibleChanged(e);
if (Visible)
{
labelProgress.Text = "Updating installation...";
progressBar.Value = 5;
await Task.Delay(1000);
progressBar.Value = 25;
// SIMULATED background task like making an API call or loading a
// database (long-running task that doesn't require the UI thread).
labelProgress.Text = "Loading avatars...";
await Task.Delay(1000);
labelProgress.Text = "Fetching game history...";
progressBar.Value = 50;
await Task.Delay(1000);
labelProgress.Text = "Initializing scenario...";
progressBar.Value = 75;
await Task.Delay(1000);
labelProgress.Text = "Success!";
progressBar.Value = 100;
await Task.Delay(1000);
DialogResult= DialogResult.OK;
}
}
}
Try this code
public partial class ssplashscreen : Form
{
public ssplashscreen()
{
InitializeComponent();
}
private void timer1_Tick(object sender, EventArgs e)
{
progressBar1.Increment(1);
if (progressBar1.Value == 100)
{
timer1.Stop();
this.Hide();
Form frm = new login();
frm.Show();
}
}
}
Try This:
namespace SplashScreen
{
public partial class frmSplashScreen : Form
{
public frmSplashScreen()
{
InitializeComponent();
}
public int LeftTime { get; set; }
private void frmSplashScreen_Load(object sender, EventArgs e)
{
LeftTime = 20;
timer1.Start();
}
private void timer1_Tick(object sender, EventArgs e)
{
if (LeftTime > 0)
{
LeftTime--;
}
else
{
timer1.Stop();
new frmHomeScreen().Show();
this.Hide();
}
}
}
}
I am trying to start a winForm from a thread, but when i do so, the form show but none of the labels are loaded ( the background where they should be is white ) and the form is frozen.
I've tried it with some other winForms that i know that work just fine and it still doesn't seem to work ? Has anyone encountered this problem ?
I know the question is vague but there isn't really any specific code that I could give to help understand the problem.
That is because the Message Loop runs on UI thread only. And when a control or window is created in any other thread, it cannot access that message loop. And thus, cannot process user input.
To solve this, try creating a window from UI thread and create a thread from that window to do whatever you want to do in different thread.
UI thread is supposed to be one.
Then, I suggest you to open your form calling a method of your original form thread, like in the example below:
(To test it just create an empty form called MainForm and paste this code in it)
public delegate void OpenFormDelegate(string txt);
public partial class MainForm : Form
{
public MainForm()
{
InitializeComponent();
var button1 = new Button();
button1.Text = "Run for 5 secs and open new window";
button1.Dock = DockStyle.Top;
this.Controls.Add(button1);
button1.Click += new EventHandler(button1_Click);
}
private void button1_Click(object sender, EventArgs e)
{
Thread t = new Thread(new ThreadStart(Run));
t.Start();
}
public void Run()
{
Thread.Sleep(5000); // sleep for 5 seconds
this.BeginInvoke(new OpenFormDelegate(OpenNewForm), "Hello World !");
}
public void OpenNewForm(string text)
{
Form f = new Form();
f.Text = text;
f.Show();
}
}
It is related to thread access, when the new form is created it will not be able to access the UI thread. Use the main thread to create the form and new thread to process the infomation.
I got to load some data out of a db4o database which takes 1 or 2 seconds at the startup of my app, the rest has to wait because first of all the data has to be loaded. doing this in an own thread would mean that the rest has to wait for the thread-finishing. I'd like to do a splash screen or something during the data is loaded for what also need an own thread, right? how would you do?
I'm using csharp, .net 3.5 and winforms
Showing a splash screen at startup is easy to do. In your application's Main() method (in Program.cs), put something like this before the Application.Run(...) line:
SplashForm splashy = new SplashForm();
splashy.Show();
Application.Run(new MainForm(splashy));
Modify the code and constructor for your main form so that it looks something like this:
private SplashForm _splashy;
public MainForm(SplashForm splashy)
{
_splashy = splashy;
InitializeComponent();
}
Then at the end of your MainForm's Load event (which presumably contains the database code), put this code:
_splashy.Close();
_splashy.Dispose();
If you choose to do your database access with a separate Thread or BackgroundWorker, then you don't really need a splash screen so much as you need some sort of progress indicator form that appears while the BackgroundWorker is doing its thing. That would be done differently from my answer here.
One way, probably better ways though. Create a new dialog form that will be your progress window/splash screen. Throw a bitmap or whatever on it as the only item. Instantiate the dialog from your main program. Override the Load event for the progress form and from there launch the new thread that will do the background processing work for loading up the data. This way you can just call ShowDialog from your main app.
if you use System.ComponentModel.BackgroundWorker then you can easily wire up events for when the thread completes and automaticaly exit the dialog from that event. Control is returned back to the calling application and you're done.
I've done this sort of thing in an application before and it works fine but I'm sure it's a novice approach. Here's sample code from the Load event in the form that launches the background thread (in my case I'm opening and parsing large files):
private void FileThreadStatusDialog_Load(object sender, EventArgs e)
{
Cursor = Cursors.WaitCursor;
if (m_OpenMode)
{
this.Text = "Opening...";
StatusText.Text = m_FileName;
FileThread = new BackgroundWorker();
FileThread.RunWorkerCompleted += new RunWorkerCompletedEventHandler(FileThread_RunWorkerCompleted);
FileThread.DoWork += new DoWorkEventHandler(FileOpenThread_DoWork);
FileThread.WorkerSupportsCancellation = false;
FileThread.RunWorkerAsync();
}
else
{
this.Text = "Saving...";
StatusText.Text = m_FileName;
FileThread = new BackgroundWorker();
FileThread.RunWorkerCompleted += new RunWorkerCompletedEventHandler(FileThread_RunWorkerCompleted);
FileThread.DoWork += new DoWorkEventHandler(FileSaveThread_DoWork);
FileThread.WorkerSupportsCancellation = false;
FileThread.RunWorkerAsync();
}
}
And here's what the work completed method looks like which exist the form:
private void FileThread_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
FileThread = null;
DialogResult = DialogResult.OK;
Close();
}
Here's how I open up the progress dialog from the main dialog:
FileThreadStatusDialog thread = new FileThreadStatusDialog(m_Engine, dlg.FileName, true);
if (thread.ShowDialog(this) == DialogResult.OK)
{
m_Engine = thread.Engine;
FillTree();
}
One might want to force drawing of splashy in MusiGenesis' answer by adding
Application.DoEvents();
immediately after
splashy.Show();
EDIT 2
Okay, based on the advice on the answers below I eliminated my thread approach and now my program looks like this:
program.cs
static void Main(){
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
FrmWWCShell FrmWWCShell = null;
var splash = new FrmSplash();
splash.SplashFormInitialized += delegate
{
FrmWWCShell = new FrmWWCShell();
splash.Close();
};
Application.Run(splash);
Application.Run(FrmWWCShell);
}
And FrmSplash.cs like this:
public partial class FrmSplash : Form
{
public FrmSplash()
{
InitializeComponent();
}
protected override void OnLoad(EventArgs e)
{
splashTimer.Interval = 1;
splashTimer.Tick +=
delegate { if (SplashFormInitialized != null) SplashFormInitialized(this, EventArgs.Empty); };
splashTimer.Enabled = true;
}
public event EventHandler SplashFormInitialized;
}
The problem is that it doesn't work at all now. The splash screen pops up for a split second, the marque progress bar never even initializes, and then disappears while I wait the 10 secs for the dll's and Main Form to show up while staring at nothing....
Color me severely confused now!
ORIGINAL POST--> for reference
I implemented a App Loading splash screen that operates on a seperate thread while all of the dll's are loading and the form is getting "Painted." That works as expected. What is strange is that now when the Splash form exits it sends my main Form to the back, if there is anything else open(i.e. Outlook). I start the thread in Program.cs,
static class Program
{
public static Thread splashThread;
[STAThread]
static void Main()
{
splashThread = new Thread(doSplash);
splashThread.Start();
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new FrmWWCShell());
}
private static void doSplash()
{
var splashForm = new FrmSplash();
splashForm.ShowDialog();
}
}
And then I end it once my FrmSearch_Shown event is fired.
private void FrmSearch_Shown(object sender, EventArgs e)
{
Program.splashThread.Abort();
this.Show();
this.BringToFront();
}
I, as you can see, have tried calling a Show() and/or BringToFront() on FrmSearch and it still "jumps" to the back.
What am I missing?
What else can I try?
Am I doing this so horribly ignorant that it is my process that is causing this?
Should I file for early retirement?
Thanks for any insight!
EDIT 1
I tried setting the TopMost Property on my Main Form to TRUE. This keeps my form from hiding but it also keeps the user from looking at any other app. Seems a little narcissistic of me...
First of all, it's very important that UI work is done on the primary application thread. I'm actually kind of surprised that you're not getting more serious errors already by showing the splash screen on a background thread.
Here's a technique I've used:
Use Application.Run on your splash form rather than your "real" form.
In your splash form, have an initialized event:
public event EventHandler SplashFormInitialized
Create a timer that fires in one millisecond, and triggers that event.
Then in your application run method you can load your real form, then close your splash form and do an Application.Run on the real form
var realForm = null;
var splash = new SplashForm();
splash.SplashFormInitialized += delegate {
// As long as you use a system.windows.forms.Timer in the splash form, this
// handler will be called on the UI thread
realForm = new FrmWWCShell();
//do any other init
splash.Close();
}
Application.Run(splash); //will block until the splash form is closed
Application.Run(realForm);
The splash might include:
overrides OnLoad(...)
{
/* Using a timer will let the splash screen load and display itself before
calling this handler
*/
timer.Interval = 1;
timer.Tick += delegate {
if (SplashFormInitialized != null) SplashFormInitialized(this, EventArgs.Empty);
};
timer.Enabled = true;
}
Try calling Application.DoEvents() right after show.
Warning: do not call DoEvents very often, but this is one of those time.
EDIT: Clyde noticed something I did not: you are threading this. Don't run any UI on another thread. Take out the thread, leave in the Application.DoEvents().