I have a wpf application that needs to be called with several command line arguments. How do I show them in the labels that I have put in the window just for that reason? I tried to implement data binding, but without success, - the variable is read and assigned correctly, but for some absurd reason is not shown on screen, in the label I want. Here is the code:
public partial class MainWindow : Window
{
public Notification _notif = new Notification();
public MainWindow()
{
InitializeComponent();
this.DataContext = new Notification();
}
protected override void OnClosed(EventArgs e)
{
base.OnClosed(e);
App.Current.Shutdown();
}
}
public partial class App : Application
{
protected override void OnStartup(StartupEventArgs e){
if (e.Args.Length >= 4)
{
MainWindow mainWindow = new MainWindow();
Label count_label = (Label)mainWindow.FindName("count");
count_label.DataContext = mainWindow._notif;
System.Diagnostics.Debug.WriteLine(mainWindow._notif.count + " - notif.count");
// bind the Date to the UI
count_label.SetBinding(Label.ContentProperty, new Binding("count")
{
Source = mainWindow._notif,
Mode = BindingMode.TwoWay
});
//assigning values to the labels
System.Diagnostics.Debug.WriteLine(count_label.Content + " - content of the label 'count'");
mainWindow._notif.count = e.Args[0];
System.Diagnostics.Debug.WriteLine(e.Args[0] + " is the argument n. 0");
System.Diagnostics.Debug.WriteLine(mainWindow._notif.count + " - notif.count");
System.Diagnostics.Debug.WriteLine(count_label.Content + "-------------------");
System.Diagnostics.Debug.WriteLine(count_label.Content + " - content of the label 'count'");
mainWindow._notif.count = "1234";
System.Diagnostics.Debug.WriteLine(mainWindow._notif.count + " - notif.count");
System.Diagnostics.Debug.WriteLine(count_label.Content + " - content of the label 'count'");
}
}
}
public class Notification : INotifyPropertyChanged
{
private string _count;
public string count {
get {
return _count;
}
set {
_count = value;
OnPropertyChanged("count");
}
}
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
#endregion
}
And here you can see a snippet from the xaml:
<Label x:Name="count" Content="{Binding count}" HorizontalAlignment="Center" Margin="0,10,486,0" VerticalAlignment="Top" RenderTransformOrigin="-2.895,-0.769" Height="80" Width="145" FontFamily="Arial" FontSize="64" HorizontalContentAlignment="Center"/>
Thank you anticipately.
The example illustrate how to display arguments in a label.
This is the entry point of the application:
public partial class App : Application
{
protected override void OnStartup(StartupEventArgs e)
{
var argumentsInfo = BuildArgumentsInfo(e.Args);
var viewModel = new MainWindowViewModel(argumentsInfo);
var window = new MainWindow(viewModel);
window.Show();
}
private string BuildArgumentsInfo(string[] args)
{
return args.Any()
? args.Aggregate((arg1, arg2) => arg1 + " " + arg2)
: "No arguments";
}
}
This is the view model (a data context of the view):
public interface IMainWindowViewModel
{
string Arguments { get; set; }
}
public class MainWindowViewModel : IMainWindowViewModel, INotifyPropertyChanged
{
private string _arguments;
public MainWindowViewModel(string argumentsInfo)
{
Arguments = argumentsInfo;
}
public string Arguments
{
get { return _arguments; }
set
{
_arguments = value;
RaisePropertyChanged("Arguments");
}
}
public event PropertyChangedEventHandler PropertyChanged = delegate {};
private void RaisePropertyChanged(string propertyName)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
This is the view (code behind):
public partial class MainWindow : Window
{
public MainWindow(IMainWindowViewModel viewModel)
{
InitializeComponent();
DataContext = viewModel;
}
}
And this is a label in the view (XAML):
<Label Content ="{Binding Arguments}"></Label>
Important! Your must delete StartupUri="MainWindow.xaml
from App.xaml file because MainWindow
is launched from a code behind.
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