Im working on a WPF application. I have a label called "Status_label" in MainWindow.xaml
. and I want to change its content from a different class (signIn.cs).
Normally I'm able to do this
var mainWin = Application.Current.Windows.Cast<Window>().FirstOrDefault(window => window is MainWindow) as MainWindow;
mainWin.status_lable.Content = "Irantha signed in";
But my problem is,when I'm trying to access it via different thread in signIn.cs class, it gives an error:
The calling thread cannot access this object because a different thread owns it.
Can I solve this by using Dispatcher.Invoke(new Action(() =>{..........
or something else?
EDIT: I'm gonna call this label change action from different class as-well-as separate thread
MainWindow.xaml
<Label HorizontalAlignment="Left" Margin="14,312,0,0" Name="status_lable" Width="361"/>
SignIn.cs
internal void getStudentAttendence()
{
Thread captureFingerPrints = new Thread(startCapturing);
captureFingerPrints.Start();
}
void mySeparateThreadMethod()
{
var mainWin = Application.Current.Windows.Cast<Window>().FirstOrDefault(window => window is MainWindow) as MainWindow;
mainWin.status_lable.Dispatcher.Invoke(new Action(()=> mainWin.status_lable.Content ="Irantha signed in"));
}
line var mainWin return errorThe calling thread cannot access this object because a different thread owns it.
Please guide me,
Thank you
Thank you! I wound up with a slightly different solution, but you definitely pointed me in the right direction with your answer.
For my application, I have a lot of controls in main, and most of the method calls on main were occurring from within the scope of main, so it was simpler to use the default { get; set } within MainWindow.xaml.cs (or to just define the controls in XAML).
In my parent window's code-behind, I launch the MainWindow in a separate thread like this (simplified example). The key is to define main globally, even though it is instantiated inside of Window_Loaded():
Then in my MainWindow code-behind, I just interact with the controls as though it is a simple single-threaded application (there is no control of the parent thread from the child thread in my case). I can, however, control main from the parent thread like this:
By doing it this way, I avoid the complexity of defining everything in code-behind and using the dispatcher from within the code-behind of MainWindow.xaml.cs. There are only a few spots in my application where I modify main from the parent window, so this was simpler for me, but your approach seems equally valid. Thanks again!
I resolved my question, hope somebody will need this. But don't know whether this is the optimized way.
In my mainWindow.xaml.cs :
from my SignIn.cs class
This works fine for me. You can find more details from here, Change WPF window label content from another class and separate thread
cheers!!
Thanks to the answers, they led me in the right direction. I ended up with this simple solution:
Then in my eventhandler in another class that runs in a different thred:
This to show the minimized window when i message is received via a namedPipeline.
try below snippet: