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c#wpfwinformsicommand

Rewrite "button.Click += ..." using ICommand in WPF


I am using an external SDK.

namespace ProSimSDK 
{
    public class ArmedFailure
   {
     ...
     public static event ArmedFailureEventDelegate onNew;
     public void Reset();
     ...
   }
}

namespace ProSimSDK
{
   public delegate void ArmedFailureEventDelegate(ArmedFailure armedFailure);
}

I have some trouble when I try to rewrite some Winform code by WPF. In Winform:

public Form1()
{
    InitializeComponent();
    ArmedFailure.onNew += new ArmedFailureEventDelegate(ArmedFailure_onNew);
}

// This function will be called when a new armedFailure is received
void ArmedFailure_onNew(ArmedFailure armedFailure)
{
      //Here is the code I need to rewrite in WPF.
      removeButton.Click += new EventHandler(delegate(object sender, EventArgs e)
        {
            failure.Reset();
        });
}

In WPF, I use a listbox. With some guide, I am using ListBox Template and Command. In Window1.xaml:

<DataTemplate x:Key="ListBoxItemTemplate">
    <Grid>
        <TextBlock x:Name="TB" Margin="5,10,5,5" Grid.Column="2" Height="23" Text="{Binding}" VerticalAlignment="Top" />
        <Button HorizontalAlignment="Right" Grid.Column="3" Margin="500,10,5,0" CommandParameter="{Binding}" Command="{Binding ElementName=UC_Failures_Setting, Path=OnClickCommand}" Width="80" Click="Button_Click">remove</Button>
    </Grid>
</DataTemplate>

<ListBox x:Name="listbox" ItemTemplate="{StaticResource ListBoxItemTemplate}" Margin="0,661,982,0" SelectionChanged="ListBox_SelectionChanged">

Window1.xaml.cs

public Window1()
{
    InitializeComponent();

    //How to implement the same functionality of "removeButton.Click += new EventHandler(delegate(object sender, EventArgs e) {failure.Reset();});" shown in Winform???
    OnClickCommand = new ActionCommand(x => listbox.Items.Remove(x));
}

ActionCommand.cs:

 public class ActionCommand: ICommand
 {
    private readonly Action<object> Action;
    private readonly Predicate<object> Predicate;

    public ActionCommand(Action<object> action) : this(action, x => true)
    {

    }
    public ActionCommand(Action<object> action, Predicate<object> predicate)
    {
        Action = action;
        Predicate = predicate;
    }

    public bool CanExecute(object parameter)
    {
        return Predicate(parameter);
    }
    public void Execute(object parameter)
    {
        Action(parameter);
    }

    public event EventHandler CanExecuteChanged
    {
        add
        {
            CommandManager.RequerySuggested += value;
        }
        remove
        {
            CommandManager.RequerySuggested -= value;
        }
    }
}

How does the button in my listbox implement the same functionality of

removeButton.Click += new EventHandler(delegate(object sender, EventArgs e) 
{ failure.Reset(); });

shown in Winform? In WPF I cannot write it this way. Thanks.


Solution

  • if ListBox is populated with ArmedFailure items, then the parameter which command receives, should be ArmedFailure item.

    OnClickCommand = new ActionCommand
    ( 
       x => 
       {
           var failure = (ArmedFailure)x;
           failure.Reset();
           listbox.Items.Remove(x);
       }
    );
    

    everything that was in Button.Click handler in WinForms becomes part of ICommand.Execute in wpf