Button Will Not Fire from Style

Question

Yeah, im not sure what i have done. brain feels like swiss cheese

<Window.Resources>
        <Style TargetType="{x:Type Button}">
            <Setter Property="Focusable" Value="False"/>
            <Setter Property="Background" Value="Transparent"/>
            <Setter Property="Command" Value="{Binding CommandButtonClicked}"/>
            <Setter Property="CommandParameter"  Value="{Binding Mode=OneWay, RelativeSource={RelativeSource Self}}"/>
        </Style>
    </Window.Resources>

Button that will Fire.

            <Grid DockPanel.Dock="Top">
                <TextBox BorderBrush="Transparent" BorderThickness="0" x:Name="txtInput" Padding="50,10,15,15" AcceptsReturn="True" TextChanged="txtInput_TextChanged" TextWrapping="Wrap" Foreground="Crimson" Text="{Binding UserInput, Mode=TwoWay}" Background="Transparent"/>
                <Button Width="30" VerticalAlignment="Top" HorizontalAlignment="Left" Margin="10,3,0,0">
                    <Image Source="Images/Actions list add user.ico" />
                </Button>
            </Grid>

Buttons that will not fire

<ListView x:Name="ListViewUsers" ItemsSource="{Binding UserNames}" DockPanel.Dock="Top" Foreground="Green" BorderBrush="Transparent">
                <ListView.View>
                    <GridView>
                        <GridViewColumn>
                            <GridViewColumn.HeaderTemplate>
                                <DataTemplate>
                                    <Button Margin="3,0,3,0" Width="30">
                                        <Image Source="Images/Actions user group delete.ico"/>
                                    </Button>
                                </DataTemplate>
                            </GridViewColumn.HeaderTemplate>
                            <GridViewColumn.CellTemplate>
                                <DataTemplate>
                                    <Button>
                                        <Image Source="Images/Actions list remove user.ico" Width="25"/>
                                    </Button>
                                </DataTemplate>
                            </GridViewColumn.CellTemplate>
                        </GridViewColumn>
                        <GridViewColumn Header="User ID" DisplayMemberBinding="{Binding}"/>
                    </GridView>
                </ListView.View>
            </ListView>

i have also tried adding in a separate DelegateCommand per button, but that doesnt help either. it seems to be anything that inside this ListView and is Generated at runtime after the initial render will not fire.

any ideas ?

Answer 1

In the "cell" DataTemplate it will have its DataContext set to the "item" within the data collection assigned to the ListView for which the "look" is being provided i.e. a "username".

But your style is using a binding that needs to access the object that contains the "CommandButtonClicked" property.

Thus you need a way to get back to the DataContext that is holding your "CommandButtonClicked" property.....so assuming you had set your "ViewModel" onto your Windows DataContext you could do this...

   <ListView x:Name="ListViewUsers" ItemsSource="{Binding UserNames}" DockPanel.Dock="Top" Foreground="Green" BorderBrush="Transparent">
                    <ListView.View>
                        <GridView>
                            <GridViewColumn>
                                <GridViewColumn.HeaderTemplate>
                                    <DataTemplate>
                                        <Button Margin="3,0,3,0" Width="30" DataContext="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}},Path=DataContext}">
                                            <Image Source="Images/Actions user group delete.ico"/>
                                        </Button>
                                    </DataTemplate>
                                </GridViewColumn.HeaderTemplate>
                                <GridViewColumn.CellTemplate>
                                    <DataTemplate>
                                        <Button DataContext="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}},Path=DataContext}">
                                            <Image Source="Images/Actions list remove user.ico" Width="25"/>
                                        </Button>
                                    </DataTemplate>
                                </GridViewColumn.CellTemplate>
                            </GridViewColumn>
                            <GridViewColumn Header="User ID" DisplayMemberBinding="{Binding}"/>
                        </GridView>
                    </ListView.View>
                </ListView>

There are alternative ways to do what you are doing...just one suggestion...look up routed commands (you could define one and then use it in your style e.g. Command="{x:Static mynamespace::MyCommands.DoSomething}" and then set up a CommandBinding to handle them).