Tasks managing app using MVVM and NHibernate

<UserControl x:Class="WpfApp.Views.TaskManagerView"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
             xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions"
             mc:Ignorable="d"
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="20" MaxHeight="20" MinHeight="20" />
            <RowDefinition />
            <RowDefinition Height="40" MaxHeight="40" MinHeight="40" />
        </Grid.RowDefinitions>
        <!-- Seleccion de dia-->
        <DatePicker Grid.Row="0"  SelectedDate="{Binding Path=SelectedDay}"/>
        <!-- Editor de Task -->
        <StackPanel Grid.Row="1" Orientation="Vertical">
            <StackPanel Orientation="Horizontal">
                <Label Content="Prj"/>
                <TextBox Width="200" Text="{Binding Path=CurrentTask.TaskProject.Code}" IsEnabled="False" />
                <Button Name="btShowProjectPicker" Content="...">
                    <i:Interaction.Triggers>
                        <i:EventTrigger EventName="Click">
                            <ei:CallMethodAction TargetObject="{Binding}" MethodName="ShowProjectPicker"/>
                        </i:EventTrigger>
                    </i:Interaction.Triggers>
                </Button>
                <Label FontWeight="Bold" Foreground="Red" Visibility="{Binding Path=TaskProjectInvalid}">!</Label>
            </StackPanel>
            <StackPanel Orientation="Horizontal">
                <Label Content="Act"/>
                <TextBox Width="200" Text="{Binding Path=CurrentTask.TaskActivity.Name}" IsEnabled="False" />
                <Button Name="btShowActivityPicker" Content="...">
                    <i:Interaction.Triggers>
                        <i:EventTrigger EventName="Click">
                            <ei:CallMethodAction TargetObject="{Binding}" MethodName="ShowActivityPicker"/>
                        </i:EventTrigger>
                    </i:Interaction.Triggers>
                </Button>
                <Label FontWeight="Bold" Foreground="Red" Visibility="{Binding Path=TaskActivityInvalid}">!</Label>
            </StackPanel>
            <StackPanel Orientation="Horizontal">
                <Label Content="Hours"/>
                <TextBox Width="40">
                    <Binding>
                        <Binding.Path>CurrentTask.TaskHours</Binding.Path>
                        <Binding.Mode>TwoWay</Binding.Mode>
                    </Binding>
                </TextBox>
                <Label FontWeight="Bold" Foreground="Red" Visibility="{Binding Path=TaskHoursInvalid}">!</Label>
            </StackPanel>
            <ListBox MinHeight="160" ItemsSource="{Binding Path=TasksOfDay}" SelectedValue="{Binding Path=ListSelection, Mode=TwoWay}">
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal">
                            <Label Content="{Binding Path=TaskHours}"/>
                            <Label Content=" / "/>
                            <Label Content="{Binding Path=TaskProject.Code}"/>
                            <Label Content=" / "/>
                            <Label Content="{Binding Path=TaskActivity.Name}"/>
                        </StackPanel>
                    </DataTemplate>
                </ListBox.ItemTemplate>
                <!--<i:Interaction.Triggers>
                    <i:EventTrigger EventName="SelectionChanged">
                        <ei:CallMethodAction TargetObject="{Binding}" MethodName="TaskListSelectionChanged"/>
                    </i:EventTrigger>
                </i:Interaction.Triggers>-->
            </ListBox>          
        </StackPanel>
        <!-- Botones de accion-->
        <StackPanel Grid.Row="2" Orientation="Horizontal">
            <Button Content="New" IsEnabled="True" Visibility="Visible">
                <i:Interaction.Triggers>
                    <i:EventTrigger EventName="Click">
                        <ei:CallMethodAction TargetObject="{Binding}" MethodName="CreateNewTask"/>
                    </i:EventTrigger>
                </i:Interaction.Triggers>                
            </Button>
            <Button Content="Del">
                <i:Interaction.Triggers>
                    <i:EventTrigger EventName="Click">
                        <ei:CallMethodAction TargetObject="{Binding}" MethodName="DelCurrentTask"/>
                    </i:EventTrigger>
                </i:Interaction.Triggers>
            </Button>
            <Button Content="Save" IsEnabled="{Binding Path=SaveTaskEnabled}">
                <i:Interaction.Triggers>
                    <i:EventTrigger EventName="Click">
                        <ei:CallMethodAction TargetObject="{Binding}" MethodName="SaveCurrentTask"/>
                    </i:EventTrigger>
                </i:Interaction.Triggers>
            </Button>
            <Button Content="Report">
                <i:Interaction.Triggers>
                    <i:EventTrigger EventName="Click">
                        <ei:CallMethodAction TargetObject="{Binding}" MethodName="ShowReportModule"/>
                    </i:EventTrigger>
                </i:Interaction.Triggers>
            </Button>            
        </StackPanel>
    </Grid>
</UserControl>