Why is my busy page not working? - wpf

Question

I'm trying to develop a busy Window as said here and here. I want a grid to be visible whenver I need it to be visible, for example while I'm doing a long task.
I did this til now:
The XAML:
<Window x:Class="LoadingWindow2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:loadingWindow2="clr-namespace:LoadingWindow2"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<loadingWindow2:BoolToVisibilityConverter x:Key="boolConverter"/>
</Window.Resources>
<Grid>
<Label HorizontalAlignment="Right">
<Hyperlink Command="{Binding Path=DoSomething}">Do Something</Hyperlink>
</Label>
<Border BorderBrush="Black" BorderThickness="1" Background="#80000000" Visibility="{Binding IsBusy, Converter={StaticResource boolConverter}}" Grid.RowSpan="3">
<Grid>
<TextBlock Margin="0" TextWrapping="Wrap" Text="Please Wait..." HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="24" FontWeight="Bold" Foreground="#7EFFFFFF"/>
</Grid>
</Border>
</Grid>
My .cs:
The BusyViewModel.cs:
public class BusyViewModel : INotifyPropertyChanged
{
private ICommand doSomethingCommand;
public event PropertyChangedEventHandler PropertyChanged;
public bool IsBusy { get; set; }
public ICommand DoSomething
{
get { return doSomethingCommand ?? (doSomethingCommand = new DelegateCommand(LongRunningTask)); }
}
private void LongRunningTask()
{
var task = new Task(ComputeResults);
task.Start();
}
private void ComputeResults()
{
this.IsBusy = true;
Thread.Sleep(5000);
this.IsBusy = false;
}
}
The DelegateCommand.cs:
public class DelegateCommand : ICommand
{
private readonly Action executeMethod;
private readonly Func<bool> canExecuteMethod;
public DelegateCommand(Action executeMethod)
: this(executeMethod, () => true)
{
}
public DelegateCommand(Action executeMethod, Func<bool> canExecuteMethod)
{
if (executeMethod == null)
throw new ArgumentNullException("executeMethod");
if (canExecuteMethod == null)
throw new ArgumentNullException("canExecuteMethod");
this.executeMethod = executeMethod;
this.canExecuteMethod = canExecuteMethod;
}
public event EventHandler CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
public bool CanExecute(object stupid)
{
return CanExecute();
}
public bool CanExecute()
{
return canExecuteMethod();
}
public void Execute(object parameter)
{
Execute();
}
public void Execute()
{
executeMethod();
}
public void OnCanExecuteChanged()
{
CommandManager.InvalidateRequerySuggested();
}
}
MainWindow.xaml.cs:
public MainWindow()
{
InitializeComponent();
this.DataContext = new BusyViewModel();
}
I downloaded the source code from the first link I copied, and the busy Grid is showing. But in my case... is NOT!!! What I'm doing wrong here?
EDIT: I deleted the Converter as suggested. But it's not working yet... I add my `MainWindow.xaml.cs"
The whole source: here

Answer 1

There is a converter available from WPF already, the "booleanToVisibilityConverter" that does the job.
See http://msdn.microsoft.com/de-de/library/system.windows.controls.booleantovisibilityconverter%28v=vs.110%29.aspx
Edit your xaml like this:
<Window x:Class="LoadingWindow2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:loadingWindow2="clr-namespace:LoadingWindow2"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<BooleanToVisibilityConverter x:Key="boolConverter"/>
</Window.Resources>
<Grid x:Name="ROOT">
<Label HorizontalAlignment="Right">
<Hyperlink Command="{Binding Path=DoSomething}">Do Something</Hyperlink>
</Label>
<Border BorderBrush="Black" BorderThickness="1" Background="#80000000" Visibility="{Binding Path=IsBusy, Converter={StaticResource boolConverter}}" Grid.RowSpan="3">
<Grid>
<TextBlock Margin="0" TextWrapping="Wrap" Text="Please Wait..."
horizontalAlignment="Center" VerticalAlignment="Center" FontSize="24" FontWeight="Bold" Foreground="#7EFFFFFF"/>
</Border>
</Grid>
EDIT: Implementation of BusyViewMOdel
public class BusyViewModel : INotifyPropertyChanged
{
private ICommand doSomethingCommand;
public event PropertyChangedEventHandler PropertyChanged;
private bool _isBusy = false;
public bool IsBusy
{
get { return _isBusy; }
set
{
_isBusy = value;
OnPropertyChanged("IsBusy");
}
}
// Create the OnPropertyChanged method to raise the event
protected void OnPropertyChanged(string name)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(name));
}
}
public ICommand DoSomething
{
get { return doSomethingCommand ?? (doSomethingCommand = new DelegateCommand(LongRunningTask)); }
}
private void LongRunningTask()
{
var task = new Task(ComputeResults);
task.Start();
}
private void ComputeResults()
{
this.IsBusy = true;
Thread.Sleep(5000);
this.IsBusy = false;
}
}
See http://msdn.microsoft.com/de-de/library/ms743695%28v=vs.110%29.aspx
EDIT: Try to set the data context on the root grid by giving the grid a name and instead of this.DataContext = ... in public MainWindow() ...do ROOT.DataContext = .... See updated xaml!
EDIT: Got it working. See this code of class BusyViewModel.
private void LongRunningTask()
{
var task = new Task(ComputeResults);
task.Start();
}
private void ComputeResults()
{
this.IsBusy = true; // you did _isBusy = true. but to invoke OnPropertyChanged you need to use the setter, thus IsBusy! Works now even if set in the worker thread. Put it back to ComputeResults!
Thread.Sleep(5000);
this.IsBusy = false;
}