Pass descendant object as command parameter

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Hello ! So i am creating a WPF application using the MVVM architectural pattern. Inside this application i have a listview. I have binded the SizeChanged event of the window to a command using this piece of XAML code:

<i:EventTrigger EventName="SizeChanged">
            <i:InvokeCommandAction Command="{Binding WindowSizeChangedCommand}"/>
        </i:EventTrigger>

Now, what i want is to pass to this command a parameter, which is the listview width.

I tried to to this by the following code:

<i:EventTrigger EventName="SizeChanged">
            <i:InvokeCommandAction Command="{Binding WindowSizeChangedCommand}" CommandParameter="{Binding Width, ElementName=listView}"/>
        </i:EventTrigger>

The thing is that it doesn't work ! Hhahahahaha I know how to find an ancestor object with XAML. But i don't know how to do the opposite. Any ideas what to do ?? THank you very much for your time !

What I have tried:

<pre><i:EventTrigger EventName="SizeChanged">
            <i:InvokeCommandAction Command="{Binding WindowSizeChangedCommand}" CommandParameter="{Binding Width, ElementName=listView}"/>
        </i:EventTrigger>

Posted 14-Apr-17 11:25am

xXxRevolutionxXx

Updated 18-Apr-17 10:26am

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J. Calhoun 18-Apr-17 16:03pm

What does your WindowSizeChangedCommand look like? Also, a tip, there was an issue that CommandParameter needed to be declared before the Command, I am not sure if that issue was resolved, or what version you are using but it is worth a try... but with command paramater declared first the relay should have something like "new RelayCommand(param => WindowSizeChange(param)); the param would be the CommandParameter that you passed in.

Also, I found that using width gave me NaN, but the property "Actual Width" gave me the actual number.

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J. Calhoun · Answer 1 · 2017-04-18T10:26:00

<i:EventTrigger EventName="SizeChanged">
            <i:InvokeCommandAction Command="{Binding WindowSizeChangedCommand}" CommandParameter="{Binding ElementName=listView, Path=ActualWidth}"/>
        </i:EventTrigger>

C#

public RelayCommand WindowSizeChangedCommand
{
    get
    {
        if (WindowSizeChangedCommand == null)
                WindowSizeChangedCommand = new RelayCommand(param => WidowSizeChanged(param));

            return WindowSizeChangedCommand;
    }
}

public void WindowSizeChanged(object param)
{
    int width = Convert.ToInt32(param);
}

I tried this exact code putting the event trigger under the <window> tag, and it works for me.