I'm trying to do what is described in this post, display a log in window and when user successfully logs in, close it and open the main window of the application.
If the user logs on successfully, then I want to show the main window, if not, I want to exit the application
but the provided answers (at the time of posting this question) do not work for me since my code to show the windows is running from the App.cs.
I know the reason, its because the first window that starts up is automatically set to be the MainWindow of the application and when I call Close() on it, it exits the application. So the second window doesn't have a chance to open.
My question is how to overcome this? Or is this just not possible the way I described?
public partial class App : Application
{
public App(){}
private void Application_Startup(object sender, StartupEventArgs e)
{
LoginScreen f = new LoginScreen(); //becomes automatically set to application MainWindow
var result = f.ShowDialog(); //View contains a call to Close()
if (result == true) //at this point the LoginScreen is closed
{
MainWindow main = new MainWindow();
App.Current.MainWindow = main;
main.Show(); //no chance to show this, application exits
}
}
}
You can change application shutdown mode to OnExplicitShutdown and then call Application.Shutdown(0) whenever you want to. For example:
public App()
{
App.Current.ShutdownMode = ShutdownMode.OnExplicitShutdown;
}
protected override void OnStartup(StartupEventArgs e)
{
base.OnStartup(e);
if (MessageBox.Show("Continue?", "", MessageBoxButton.YesNo) == MessageBoxResult.No)
App.Current.Shutdown(0);
}
Here in the constructor I'm changing application shudown mode and calling Shutdown method if I need to.
Caution: When you change ShutdownMode make sure to call Shutdown method otherwise your application will be in memory even after main window closes. I've overrided OnClosed method in my MainWindow to do that:
protected override void OnClosed(EventArgs e)
{
base.OnClosed(e);
App.Current.Shutdown(0);
}
App.xaml : (In this file set the start window with the login view)
StartupUri="LoginWindow.xaml"
LoginWindow.xaml : (A file with a login window view)
LoginWindow.xaml.cs : (Code Behind for the view. Place here the function assigned to login. )
private void Login_Click(object sender, RoutedEventArgs e)
{
//Access control. If correct, go ahead. Here you must create a condition check
MainWindow main = new MainWindow();
main.Show();
this.Close();
}
Related
Hey there StackOverflow community!
So I've been working on an application that checks if the user has entered valid credentials in a Login() form, then it switches over to an Intro_Sequence() form (where a .mp4 file is played in fullscreen mode) as a sort of aesthetic addition to the app. So far so good, no problems whatsoever.
The problem comes right after the Intro ends, where supposedly the application should switch over to a third form, called Main().
I have implemented a check whenever Windows Media Player (aka axWMPLib) changes its PlayState to see whether it has finished the playback.
If it has, then the Hide() event is called to conceal the current Form's window, then main.ShowDialog() should open the third form.
Afterwards, I call the Close() event to close the previous Form's window entirely.
Here is the code so far:
public partial class Intro_Sequence : Form
{
public static string Username;
public Intro_Sequence(string username)
{
InitializeComponent();
Username = username;
FormBorderStyle = FormBorderStyle.None;
Bounds = Screen.PrimaryScreen.Bounds;
TopMost = true;
intro.uiMode = "none";
intro.URL = AppDomain.CurrentDomain.BaseDirectory + "\\Intro.mp4";
intro.enableContextMenu = false;
DisableMouseClicks();
}
private void DisableMouseClicks()
{
if (this.Filter == null)
{
this.Filter = new MouseClickMessageFilter();
Application.AddMessageFilter(this.Filter);
}
}
private MouseClickMessageFilter Filter;
private const int LButtonDown = 0x201;
private const int LButtonUp = 0x202;
private const int LButtonDoubleClick = 0x203;
public class MouseClickMessageFilter : IMessageFilter
{
public bool PreFilterMessage(ref System.Windows.Forms.Message m)
{
switch (m.Msg)
{
case LButtonDown:
case LButtonUp:
case LButtonDoubleClick:
return true;
}
return false;
}
}
private void Intro_Sequence_Load(object sender, EventArgs e)
{
}
private void intro_PlayStateChange(object sender, AxWMPLib._WMPOCXEvents_PlayStateChangeEvent e)
{
if(intro.playState == WMPLib.WMPPlayState.wmppsMediaEnded)
{
Main main = new Main(Username);
this.Hide();
main.ShowDialog();
this.Close();
}
}
}
As you can see I have also added a filter to block clicks during playback, so as not to allow the user to pause it.
However, when I execute this code, it works perfectly fine until it finishes the video and then closes abruptly.
I tried putting breakpoints and everything seems to be fine.
It does call everything I tell it to call, yet the form doesn't even appear.
I have also tried several other alternatives, like not closing the Form at all, calling Show() instead of ShowDialog() and even not Hiding it at all.
It is as if it either freezes there or closes instantly without any sign of the Main form showing.
I also tried calling the Main() form from the Login() and it works perfectly from there.
I really don't know what is going on.
Any help would be appreciated.
How about something like this?
There are three forms. There's a Login form (in this case, it's just an empty form - you close it by clicking on the red X). It is popped up modally from within the Main form (while the main form is hidden).
There's a Splash screen on which your video is to play. I fake out the video by using await Task.Delay(4000); to get a pause. After the 4 second delay, I raise an event (equivalent to your media player event). What I do is show this modally from the main form. I put the event handler in this form; when the event is raised, I close the splash screen modal. The entire (non-designer) code for that form looks like (and, since there are no controls on this form, the designer code is pretty lean):
public partial class SplashScreen : Form
{
public event EventHandler SplashFinished;
public SplashScreen()
{
InitializeComponent();
this.SplashFinished += SplashScreen_SplashFinished;
}
private async void SplashScreen_Load(object sender, EventArgs e)
{
await Task.Delay(4000);
SplashFinished?.Invoke(this, new EventArgs());
}
private void SplashScreen_SplashFinished(object sender, EventArgs e)
{
this.DialogResult = DialogResult.OK;
this.Close();
}
}
Then there's the Main form. It gets fired up in the normal way from Program.cs:
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
The only thing that I added to that form (from the out-of-the-box code) is:
private void Form1_Load(object sender, EventArgs e)
{
this.Hide();
var login = new LoginForm();
//should really check this, but for now
login.ShowDialog(this);
var splash = new SplashScreen();
splash.ShowDialog(this);
this.Show();
}
So, when the app starts, the user is shown the login form (the main form is hidden). He does what is needed to do (and the result is checked in the main form's Form1_Load handler.
If everything is cool, a new SplashScreen form is created and shown modally. When it pops up, the video starts (in this case, the video is simply an asynchronous timer). When the video ends, the SplashScreen handles the finished event, and uses it to close itself.
Once control returns to the main form, it displays itself.
I want to have a return value from my WPF window without close it.
I have an DLL with WPF usercontrol inside, I call it from my DLL code.
I have to call it, it returns me datas, then I send it datas.
But I don't want to create two different instance of the same window.
My code :
MP.UserControl1 a = new MP.UserControl1();
a.ShowDialog();
if (a.DialogResult.HasValue && a.DialogResult.Value == true)
{
a.Hide();
InitialDatas = a.inputData;
}
else
return 0;
Then I elaborate InitialDatas
And now I want to call a method inside my "a", and show it again, without create a new window.
Code :
a.SetValue(result, off1, InitialDatas);
a.ShowDialog();
I got error message : Cannot set visibility or call Show, ShowDialog or EnsureHandle after a window has been closed
Is it possible to solve?
I would solve this with an event model. You could do the following:
Create an event in the Form
Create an event handler in the caller
Subscribe to the event and do your logic
The called form:
namespace MyApplication
{
public delegate void MyEventHandler(object source, EventArgs e);
public class MyForm : Form
{
public event MyEventHandler OnInitialData;
private void btnOk_Click(object sender, EventArgs e)
{
OnInitialData?.Invoke(this, null);
}
}
}
In your other Form:
MP.UserControl1 a = new MP.UserControl1();
a.OnInitialData += UCA_OnInitialData;
private void UCA_OnInitialData(object sender, EventArgs e)
{
MP.UserControl1 a = sender as MP.UserControl1;
a.SetValue(result, off1, a.inputData);
}
a.ShowDialog();
As the error message states, you cannot close the window and then open it again.
Instead of closing a window you could hide it by calling the Hide() method and then showing it again by calling the Show() method.
But since the ShowDialog() method doesn't return until the window has been closed, this won't work for a dialog window though. If you require a modal window, you will have to create a new instance of the window and open this one. This shouldn't really be an issue though.
So I guess the answer to your question is simply no. You cannot re-open a closed dialog window.
I'm trying to bring my MainWindow into view when I close a specific window within the same application. I have tried to do this but with the code I have created it just creates a new instance of MainWindow and I end up having 2 MainWindows instead of a desired one. Here is the code below that I have got.
private void Weight_Click(object sender, RoutedEventArgs e)
{
try
{
MultipleConverters.Windows.Weight WeightCalculation = new Windows.Weight();
WeightCalculation.Show();
this.WindowState = WindowState.Minimized;
}
// This code above works fine and minimizes the mainwindow and brings into view the selected window.
private void Quit_Click(object sender, RoutedEventArgs e)
{
this.Close();
MainWindow bringIntoView = new MainWindow();
bringIntoView.Show();
}
// Now with this code above is the problem code. This code is within the new window and what Iam trying to achieve is when this window is closed the mainwindow will be brought back into scope rather than creating a new instance of it, and leaving me with 2 Mainwindows rather than the desired 1 Mainwindow. any help would be great.
Use the Owner property to store the reference to the main window, you can then use that property to bring the window back up.
private void Weight_Click(object sender, RoutedEventArgs e)
{
try
{
MultipleConverters.Windows.Weight WeightCalculation = new Windows.Weight();
WeightCalculation.Owner = this;
WeightCalculation.Show();
this.WindowState = WindowState.Minimized;
}
elsewhere
private void Quit_Click(object sender, RoutedEventArgs e)
{
this.Close();
Owner.WindowState = WindowState.Normal;
}
However based on the behavior you are showing you may want to look in to using ShowDialog() instead of minimizing the parent window and use that instead.
private void Weight_Click(object sender, RoutedEventArgs e)
{
try
{
MultipleConverters.Windows.Weight WeightCalculation = new Windows.Weight();
WeightCalculation.Owner = this;
WeightCalculation.ShowDialog(); //The code pauses here till the dialog is closed.
}
Application.Current.MainWindow.Activate();
There is a handy property Application.Current.MainWindow that you can use to access the main window declared in App.xaml, you should just be able to show it by calling:
Application.Current.MainWindow.Show();
Application.Current.MainWindow.Activate();
To simplify things, you could create a static method on your MainWindow which handles all this:
public static void TryReveal()
{
var mainWindow = Application.Current.MainWindow;
if (mainWindow == null)
{
// The main window has probably been closed.
// This will stop .Show() and .Activate()
// from throwing an exception if the window is closed.
return;
}
if (mainWindow.WindowState == WindowState.Minimized)
{
mainWindow.WindowState = WindowState.Normal;
}
// Reveals if hidden
mainWindow.Show();
// Brings to foreground
mainWindow.Activate();
}
And then your other windows can just call MainWindow.TryReveal(). That way your windows don't need any reference to the main window as the static method handles it.
The best way you could handle this in WPF though is (I think) using a messaging implementation (eg. MVVM Light's Messaging system, or Caliburn.Micro's EventAggregator). Your MainWindow would subscribe to a "MainWindowViewStateMessage" or something like that (defined by you) and your other windows would pass it through the messaging system. The main window would intercept it and do the necessary work.
private void Quit_Click(object sender, RoutedEventArgs e)
{
this.Close();
MainWindow bringIntoView = new MainWindow();
bringIntoView.Show();
}
You're creating a new instance of MainWindow and then showing it. This is why a new MainForm is shown.
One thing you can do is set a property on the WeightCalculation window like this:
public MainWindow _mainWindow { get; set; }
Before showing the WeightCaculation, set _mainWindow to your current instance of MainWindow :
MultipleConverters.Windows.Weight WeightCalculation = new Windows.Weight();
WeightCalculation._mainWindow = this;
WeightCalculation.Show();
this.WindowState = WindowState.Minimized;
and from the new form you can now interact with the MainWindow.
I'm building a GUI application with C# and gtk#. I've encountered an issue recently and was looking for the best solution to this problem:
I have a modal window that pops up for the user to enter a number. This window is a separate window accessed from my main window and it's set up like this:
public class MainWindow()
{
public NumberEntry numEntry;
Whenever I need numerical input from the user, I call ShowAll() on the public Window property of NumberEntry like:
numEntry.win.ShowAll();
And all of this works fine. Afterwards, to get the value they entered, I call:
int entered = numEntry.valueEntered;
The issue is obviously that code continues executing immediately after the ShowAll() line is finished, and numEntry.valueEntered is always 0. What I'd like to do (and have been trying to do), is to suspend the main thread, and open up the number entry window in a second thread, and join back to the main thread when this is complete. Suspending the main thread seems to prevent GUI changes making the program freeze when I try to open the number entry window. I'd also like to avoid callback methods if at all possible, seeing as how this would get rather complicated after awhile. Any advice? Thanks!
Seems like when GTK window is closed all its child controls are cleared. So to get the result from the custom dialog window you may do the following (I am not gtk guru but its works for me):
1. Create a new dialog window with your controls (I used Xamarin studio). Add result properties, OK and Cancel handlers and override OnDeleteEvent method:
public partial class MyDialog : Gtk.Dialog
{
public string Results {
get;
private set;
}
public MyDialog ()
{
this.Build ();
}
protected override bool OnDeleteEvent (Gdk.Event evnt)
{
Results = entry2.Text; // if user pressed on X button..
return base.OnDeleteEvent (evnt);
}
protected void OnButtonOkClicked (object sender, EventArgs e)
{
Results = entry2.Text;
Destroy ();
}
protected void OnButtonCancelClicked (object sender, EventArgs e)
{
Results = string.Empty;
Destroy ();
}
}
2. In your main window create a dialog object and attach to its Destroyed event your event handler:
protected void OnButtonClicked (object sender, EventArgs e)
{
var dialog = new MyDialog ();
dialog.Destroyed += HandleClose;
}
3. Get the results when dialog is closed:
void HandleClose (object sender, EventArgs e)
{
var dialog = sender as MyDialog;
var textResult = dialog.Results;
}
If you whant you also may specify a dialog result property and etс.
I have login window. From this login window, i am intializing the main window.
Once login successfully happened, i close the login window.
Now i am having two other windows, which i am calling from Main Window.
Once i close the main Window, I am able to close the other two windows as well as Main Window.
But program still runs in memory. I have to close it manually from the Visual Studio.
How should i close the Program all instances fully??
This is the Main window Close Event code.
private void usimClose(object sender, EventArgs e)
{
newScreen2.Close();
newScreen3.Close();
this.Close();
}
This is my Login Window Code. Once the user click on the submit button.
private void btnLogin_Click(object sender, RoutedEventArgs e)
{
if (txtUserName.Text.Length == 0)
{
errormessage.Text = "Please Enter UserName";
txtUserName.Focus();
}
else
{
LoginStatus _status = _Login.LoginUsimgClient(txtUserName.Text, txtPassword.Password.ToString());
if (_status.BoolLoginstatus)
{
mainWindow.RunApplication();
string struserName = _status.StringUserFirstName;
mainWindow.userName.Text = "Welcome " + struserName;
mainWindow.Show();
this.Close();
}
else
{
errormessage.Text = _status.StringErrorDescription;
txtUserName.Text = String.Empty;
txtPassword.Password = String.Empty;
}
}
}
Try Application.Current.Shutdown();
From MSDN
Calling Shutdown explicitly causes an application to shut down,
regardless of the ShutdownMode setting. However, if ShutdownMode is
set to OnExplicitShutdown, you must call Shutdown to shut down an
application.
Important note
When Shutdown is called, the application will shut down irrespective
of whether the Closing event of any open windows is canceled.
This method can be called only from the thread that created the
Application object.
You can close all windows using this
App.Current.Shutdown();
or
you can manually close it
Window parentwin = Window.GetWindow();
parentwin.Close();
If you starting point is your MainWindow, then just start there.
Firstly, host the LoginForm in your MainWindow, and show it using ShowDialog() to force the user to interact with the LoginForm. Return the result of a successful/unsuccessful interaction to the MainForm.
private void MainWindow_OnLoaded(object sender, RoutedEventArgs e)
{
var form = new LoginForm();
var result = form.ShowDialog();
if (result ?? false)
{
// Carry on opening up other windows
}
else
{
// Show some kind of error message to the user and shut down
}
}
Otherwise, technically your LoginForm is hosting your MainForm which is, frankly, odd.
Have a look at my answer here: How to close wpf window from another project
An Application.Current.Shutdown() will stop the application in a very abrupt way.
It is better to gracefully keep track of the windows and close them.