ListView内部的按钮C＃

Question

I've successfully put a button inside each listview item. But I want to obtain the Item on which the button is.. In this case each item is a Friend and has a button on click of the button I want to now which friend it is. How can I achieve this?

VIEW

 <ListView x:Name="dataGrid" ItemsSource="{Binding Friends}" Height="314" BorderThickness="0" SelectedItem="{Binding SelectedItemFriends}">
        <ListView.ItemTemplate>
            <DataTemplate>
                <StackPanel Orientation="Horizontal">
                    <Image Source="Resources\Images\ic_status.png" Height="24" Width="18"/>
                    <StackPanel Margin="5" Orientation="Vertical">
                            <TextBlock FontWeight="Bold" Text="{Binding name}"/>                                
                        <StackPanel x:Name="RemoveItems" Margin="5" Orientation="Vertical">
                            <TextBlock Text="{Binding lastLocation}"/>
                            <TextBlock Text="{Binding timestamp}"/>
                        </StackPanel>
                        <StackPanel x:Name="AdditionItems" Margin="5" Orientation="Vertical" Visibility="Collapsed">
                            <TextBlock Text="{Binding Path=loc.area}"/>
                            <TextBlock Text="{Binding Path=loc.building}"/>
                            <TextBlock Text="{Binding Path=loc.floor}"/>
                            <TextBlock Text="{Binding Path=loc.room}"/>
                        </StackPanel>
                    </StackPanel>
                    <Button Style="{DynamicResource FlatButtonStyle}" Command="{Binding DataContext.SelectViewCommand, ElementName=GeneralWindowView}"  CommandParameter="ChatViewModel"  x:Name="button1" Content="Chat" Margin="10">
                        <Button.Template>
                            <ControlTemplate>
                                <Image Source="Resources\Images\chat_image.png"/>
                            </ControlTemplate>
                        </Button.Template>
                    </Button>
                </StackPanel>
                <DataTemplate.Triggers>
                    <DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ListViewItem}}, Path=IsSelected}" Value="true">
                        <Setter TargetName="AdditionItems" Property="Visibility" Value="Visible"/>
                        <Setter TargetName="RemoveItems" Property="Visibility" Value="Collapsed"/>
                    </DataTrigger>
                </DataTemplate.Triggers>
            </DataTemplate>
        </ListView.ItemTemplate>
    </ListView>

Best regards, Antoine

Answer 1

You can bind the CommandParameter to the ListViewItem to which the Button belongs. Something like:

<Button x:Name="button1"
        Command="{Binding DataContext.SelectViewCommand,
          ElementName=GeneralWindowView}"
        CommandParameter="{Binding}">

In this way, the CommandParameter is always the ViewModel of the ListViewItem on which the Button stays.

As a side node, I think that if the SelectViewCommand deals with the current ListViewItem , maybe the Command should stay on the ViewModel of the ListViewItem , not the one on the GeneralWindowView ...

Any way, hope this helps.

Answer 2

You could do something like this....

class Friend
{
    // Other properties......
    public string Link_1 { get; set; }
}

set Link_1 = "ChatViewModel" somewhere

XAML

<Button x:Name="button1" Command="{Binding DataContext.SelectViewCommand, ElementName=GeneralWindowView}" CommandParameter="{Binding}">

then in your SelectViewCommand Command handler

public void OnSelectViewCommand (dynamic obj)
{
    this.Current_ViewModel = this.GetViewModel(obj.Link_1);
}

EDIT........

There is another way that directly addresses the issue of sending multiple parameters in the CommandParameter...

XAML

add the manespace

xmlns:Converters="clr-namespace:CommandParameterExample.Converters"

add the Resource

<UserControl.Resources>
    <Converters:CommandParameter_Converter x:Key="CommandParameter_Converter" />
</UserControl.Resources>

Add a hidden Text Block

<TextBlock Visibility="Collapsed" Name="VM" Text="ChatViewModel"></TextBlock>

Here is your Button

<Button Content="Chat" Command="{Binding DataContext.SelectViewCommand, ElementName=GeneralWindowView}" >
    <Button.CommandParameter>
        <MultiBinding Converter="{StaticResource CommandParameter_Converter}">
            <Binding/>
            <Binding Path="Text" ElementName="VM"/>
        </MultiBinding>
    </Button.CommandParameter>
</Button>

Here is the CommandParameter_Converter

class CommandParameter_Converter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        return values.Clone(); // simply return an array
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

and here is your SelectViewCommand

public void OnSelectViewCommand (object parameter)
{
    var values = (object[])parameter;
    var FriendObject = (dynamic)values[0];
    var ViewModelName = (string)values[1];
}

This is the correct way to resolve your issue (sending 2 arguments in CommandParameter). But as you can see, it's rather involved....