I would like to run some code onload of a form in WPF. Is it possible to do this? I am not able to find where to write code for form onload.
Judging by the responses below it seems like what I am asking is not something that is typically done in WPF? In Vb.Net winforms it is easy, you just go to the onload event and add the code that you need ran on load. For whatever reason, in C# WPF it seem very difficult or there is no standard way to do this. Can someone please tell me what is the best way to do this?
You can subscribe to the Window's Loaded event and do your work in the event handler:
public MyWindow()
{
Loaded += MyWindow_Loaded;
}
private void MyWindow_Loaded(object sender, RoutedEventArgs e)
{
// do work here
}
Alternatively, depending on your scenario, you may be able to do your work in OnInitialized instead. See the Loaded event docs for a discussion of the difference between the two.
Use the Loaded event of the Window. You can configure this in the XAML like below:
<Window x:Class="WpfTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Your App" Loaded="Window_Loaded">
Here is what the Window_Loaded event would look like:
private void Window_Loaded(object sender, RoutedEventArgs e)
{
// do stuff
}
This question was asked 4 years ago, but this answer may help others too so here goes -->
To do it simply and quickly - down and dirty, put the code you want to run in a method in the code-behind. then simply call the method before the MainWindow() InitializeComponent(). This poses dangers, but most times it works because the components are loaded before window initiation/display.
(This is working code from one of my projects.)
Let's say you want to play a short wave file when the app fires up. It would look like this;
using ...
using System.Windows.Media;
namespace yourNamespace_Name
{
/// sumary >
/// Interaction logic for MainWindow.xaml
/// /sumary>
public partial class MainWindow : System.Windows.Window
{
public MainWindow()
{
/*call your pre-written method w/ all the code you wish to
* run on project load. It is wise to set the method access
* modifier to 'private' so as to minimize security risks.*/
playTada();
InitializeComponent();
}
private void playTada()
{
var player = new System.Media.SoundPlayer();
player.Stream = Properties.Resources.tada;
// add the waveFile to resources, the easiest way is to copy the file to
// the desktop, resize the IDE window so the file is visible, right
// click the Project in the solution explorer & select properties, click
// the resources tab, & drag and drop the wave file into the resources
// window. Then just reference it in the method.
// for example: "player.Stream = Properties.Resources.tada;"
player.Play();
//add garbage collection before initialization of main window
GC.Collect();
GC.WaitForPendingFinalizers();
}
}
}
Hope this helps those that are searching. :-)
Loaded event is raised after project is build. To do stuff before, you can ovveride OnStartup method in App.xaml.cs.
public partial class App : Application
{
protected override void OnStartup(StartupEventArgs e)
{
//...
base.OnStartup(e);
}
}
Related
I apologize if the question title isn't really specific, I'm not exactly sure how to condense the problem I'm having down to a few words. But to simplifiy the problem I'm having, here is my issue:
I'm creating a tool using WPF that consists of a TextBox that will contain a path to a directory and a Button that will allow you to Browse to a certain directory. Now, when I select the Browse button, it pops up a dialog, allows the user to select a directory and then I have some methods that will disable some buttons and updates some Brushes on the screen if the path doesn't meet a certain set of criteria. No problems there, got that working.
My problem is the TextBox that this Browse button correlates with. This TextBox is using a binding as such:
In my MainWindow.xaml (Yes, this is the simplified, focused version):
<Window>
<TextBox Text="{Binding Directory}" TextChanged="Directory_TextChanged" />
<Button Content="Browse..." Click="Browse_Click"/>
</Window>
In my code MainWindow.xaml.cs file:
public partial class MainWindow: Window
{
private ViewModel myViewModel;
public MainWindow()
{
myViewModel = new ViewModel();
this.DataContext = myViewModel;
}
private void Browse_Click(object sender, RoutedEventArgs e)
{
// Dialog stuff that's working
viewModel.Directory = dialog.SelectedPath;
}
private void InstallDir_TextChanged(object sender, TextChangedEventArgs e)
{
ValidatePath(); /* Disables/enables buttons and updates brushes based on validation. Also working */
}
private void ValidatePath() {/* */}
}
Like I mentioned earlier, the browse button works fine. I'm trying to figure out however, how I can get this to work if I type a directory alongside it. Because if I type something in the textbox, that would mean that inside of the InstallDir_TextChanged() function I would have to set viewModel.Directory, but since I have the INotifyPropertyChanged attached to this ViewModel, this function would get called recursively.
I tried doing the validation stuff within the viewmodel, but I couldn't figure out how to update the brushes/buttons in MainWindow if I did this. (Still relatively new to C# so I haven't learned the ins and outs yet. This is the first WPF tool I've been making from scratch, so just a disclaimer).
Would anyone have any ideas (or logic) I can approach to try and accomplish this? If there's any further clarification needed, that's not an issue. I don't need an exact definitive answer. Maybe some advice that could point me in the correct direction would definitely suffice. I don't have a problem trying to figure stuff out.
I'm using the WinForms version of <WebBrowser> in my WPF app, a la <WindowsFormsHost> because in general it works a lot better than the Windows.Controls version. However I have one problem that has to do with touch screens.
Normally I set the ManipulationBoundaryFeedback event handler on controls to immediately handle the event, thereby preventing any boundary feedback, and I've tried to do so with this code:
MainWindow.xaml
<WindowsFormsHost IsManipulationEnabled="True" ManipulationBoundaryFeedback="WindowsFormsHost_OnManipulationBoundaryFeedback">
<forms:WebBrowser />
</WindowsFormsHost>
MainWindow.xaml.cs
private void WindowsFormsHost_OnManipulationBoundaryFeedback(object sender, ManipulationBoundaryFeedbackEventArgs e)
{
e.Handled = true;
}
On ordinary WPF controls, generally speaking, this works. And what I mean by "works" is that if you use your finger on the touch screen and drag up or down, you don't get the effects of touch screen intertia; that is, it doesn't shift the entire window up or down once you hit the boundary.
Here's a picture to illustrate what's happening:
As you can see, if I drag down within the browser, it pulls the entire window with it. What can I do to prevent this?
Not sure if you still need this answer but to prevent this unnecessary behavior simply inherit WindowsFormsHost class and override OnManipulationBoundaryFeedback like this:
public class MyClass : WindowsFormsHost
{
// Override is optional to remove unnecessary behavior
protected override void OnManipulationBoundaryFeedback(ManipulationBoundaryFeedbackEventArgs e)
{
// uncomment this to use base class implementation
//base.OnManipulationBoundaryFeedback(e);
e.Handled = true;
}
}
Edited
I have made a small test and added this code for my control
protected override void OnManipulationBoundaryFeedback(ManipulationBoundaryFeedbackEventArgs e)
{
Debug.WriteLine("OnManipulationBoundaryFeedback");
}
private void MyControl_ManipulationBoundaryFeedback(object sender, ManipulationBoundaryFeedbackEventArgs e)
{
Debug.WriteLine("MyControl_ManipulationBoundaryFeedback");
}
and Output was the following
OnManipulationBoundaryFeedback
MyControl_ManipulationBoundaryFeedback
OnManipulationBoundaryFeedback
MyControl_ManipulationBoundaryFeedback
OnManipulationBoundaryFeedback
MyControl_ManipulationBoundaryFeedback
OnManipulationBoundaryFeedback
MyControl_ManipulationBoundaryFeedback
So you can see that OnManipulationBoundaryFeedback launched first and then it invokes ManipulationBoundaryFeedbackEvent handlers
You could turn off this behavior for the whole system:
Open registry ( run regedit command ) and set HKEY_CURRENT_USER\Software\Microsoft\Wisp\Touch Bouncing to 0;
if HKEY_CURRENT_USER\Software\Microsoft\Wisp\Touch not exist Bouncing item, add it( DWORD type, Not QWORD or String) and set it value to 0.
However, this is not a good approch, even if it solve my problem. Look at this manipulationboundaryfeedback-does-not-work-in-webbrowser-in-wpf.
I'm building an XAML app for Win 8 metro and ran into a "problem".
I have my mainpage.xaml with a button and in the mainpage.xaml.cs i have my constructor with initializecomponent(). when i click the button i call this function method:
private void GoToOtherPage()
{
this.Frame.Navigate(typeof(MySecondPage));
}
and works just fine.
However, in the contructor i also have a condition, and if true just carry on, but if it's false i want to run the GoToOtherPage() as well.
the constructor then looks somtehing like this
Public Mainpage()
{
InitializeComponent();
if(....)
{
//do some stuff
}
else
{
GoToOtherPage();
}
}
Since the initializecomponent() not is ready when this happens, i get the error Object reference not set to an instance of an object. which i (think) have found is refferring to this.Frame.
How should i do this the correct way? Put something like "WaitForThisFormToBeReady()" before the .Navigate or am i just on the complete wrong track here?
I think this.Frame becomes non-null after the page has been navigated to, so you could override OnNavigatedTo to handle it. Otherwise you can grab the Frame through (Frame)Window.Current.Content, a property on your App class or a NavigationService implementation - depending on how far you went with design patternizing your app.
I have developed a C# wpf application with Visual Studio 2012. I published it with Inno Setup. When I start my program by double clicking the item it starts ans show me GUI "A". When I minimize, it goes to notifications in task bar and shows GUI "B". What I need is let this start with windows start-up. When it starts with start-up I do not want to show GUI "A", just directly minimize it in notifications.
How can I achieve that ?
Create a task in the Windows Scheduler at the program's first run or at the install time (if possible). You can create a batch script that will do it for you. You may consult this link to learn how to work with schtasks. There a are a number of parameters that you can set in the Scheduler to allow to launch the application at session login.
As for starting your application in "minimized" mode, you will need to implement it yourself. When the application starts, you may pass parameters to the application. You should create a property that will tell your application to launch in minimized mode. To read the arguments from the Command line, you may consult this other post.
Example : C:\apps\Foo.exe -minimized
Good luck
Create one Static Variable Name as IsAppStartCall in your GUI A.
static bool IsAppStartCall = true;
2.Create Parameterised constructor for GUI A and in that check IsAppStartCall or not.
public void GUIA(bool isAppStartCall)
{
IsAppStartCall = isAppStartCall;
// do your other tasks here
}
3.Now in your Window Loaded event check above code like this
//in loaded event last statement should be like this.
//this will ensure that whenever AppstartCall=true is there then and then it will set this window to mimimise otherwise not.
if(IsAppStartCall)
{
this.WindowState=WindowState.Minimized;
IsAppStartCall= false; //as once we achieved this functionality we will set it to false
}
Find Solution that worked me
GUIA.xaml
<Window x:Class="WpfApplication1.GUIA"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Button x:Name="btnCloseAnotherWindow" Click="btnCloseAnotherWindow_Click" Content="Click Me" Width="100" Height="100"/>
</Grid>
</Window>
GUIA.xaml.cs
namespace WpfApplication1
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class GUIA : Window
{
static bool IsAppStart = true;
public GUIA()
{
InitializeComponent();
this.Loaded += GUIA_Loaded;
}
public GUIA(bool isAppStart)
{
IsAppStart = isAppStart;
this.Loaded += GUIA_Loaded;
}
void GUIA_Loaded(object sender, RoutedEventArgs e)
{
if (IsAppStart)
{
this.WindowState = System.Windows.WindowState.Minimized;
}
}
private void btnCloseAnotherWindow_Click(object sender, RoutedEventArgs e)
{
GUIA obj = new GUIA(false);
obj.Show();
}
}
}
You should design your app to accept a commandline parameter to indicate that it starts in the minimised state. Your startup commandline can then pass that argument and you can decide how to start based on whether it's present and/or its value.
I'm new into WPF and have a problem I can't seem to find a solution for.
I'm writing a G19 (Keyboard) applet. This Keyboard has a 320x240 display attached, which you can access with C#.
I'm using WPF for this, because I don't need to do any GDI drawing anymore and use the normal controls instead.
So. It works as I wish. Everything draws properly except one UserControl. I have downloaded this control -> http://marqueedriproll.codeplex.com/
In the designer, the control works, the Loaded event get's fired and the animation is good.
When I run my application, I just see the label and the text. The animation does not work, and the Loaded event does not fire anymore.
Any help is appreciated.
The main function is my wrapper. The wrapper is already a Usercontrol and displays plugins which are switchable. This wrapper has the Frame Control(Wrapper1). I replace the content of this frame every time I switch the plugin.
public void SetPlugin(IPlugin plugin)
{
if (this.MainPlugin != null)
{
this.MainPlugin.OnHide();
((UserControl)this.MainPlugin).Visibility = System.Windows.Visibility.Hidden;
}
this.MainPlugin = plugin;
((UserControl)this.MainPlugin).Visibility = System.Windows.Visibility.Visible;
this.MainPlugin.OnShow();
this.Wrapper1.Content = this.MainPlugin;
}
I think it's the right approach to handle a plugin system that way. The plugin get's drawed on my keyboard.
What I don't understand is why the usercontrol only works in the designer view and not in the running application.
The basic code of the scrolling label is so:
public MarqueeText()
{
this.Loaded += new RoutedEventHandler(MarqueeText_Loaded);
InitializeComponent();
canMain.Height = this.Height;
canMain.Width = this.Width;
}
void MarqueeText_Loaded(object sender, RoutedEventArgs e)
{
StartMarqueeing(_marqueeType);
}
I don't see a reason why it doesn't work. Actually Ive always found a way to fix a problem but this time I see nothing.
Thanks in advance. Your help is really required today.
Have a great saturday! :)
I am guessing you are rendering to a bitmap target, rather than onscreen. If you are using RenderTargetBitmap, you have a couple of responsibilities. You need to set both a presentation source, and make sure you run events on the dispatcher.
Normally, App.xaml or Application.Run does this for you, but if you are not using a Window, you are on your own.
See this related question for details.