Dear all,

Mình có 01 ListBox, trên mỗi dòng đều có button X để xóa dòng. Xin làm ơn cho mình hỏi làm cách nào để hiện MessageBox khi click vào button trên ListBox trong WPF MVVM. Mình mày mò và đã làm được click vào button thì xóa dòng nhưng không biết cách show message box ra.

Code mình như sau:

MainWindow.xaml

<Window x:Class="MVVM_ListView.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:MVVM_ListView"
        xmlns:mv ="clr-namespace:MVVM_ListView.ViewModels"
        xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Window.DataContext>
        <mv:PersonViewModel/>
    </Window.DataContext>
    
    <StackPanel Margin="5">
        <TextBox Height="24" Name="txtName" Text="[Your name]" Width="180"/>
        <Grid HorizontalAlignment="Center">
            <Grid.RowDefinitions>
                <RowDefinition/>
                <RowDefinition/>
            </Grid.RowDefinitions>
            <Grid.ColumnDefinitions>
                <ColumnDefinition/>
                <ColumnDefinition/>
            </Grid.ColumnDefinitions>
            <Button Content="Add" Height="30" Width="80" Margin="5" 
                    Name="AddButton"
                    Command="{Binding AddCommand}"
                    CommandParameter="{Binding Text, ElementName=txtName}"/>
            <Button Content="Update" Height="30" Width="80" Margin="5" 
                    Name="UpdateButton"
                    Grid.Column="1"/>
            <Button Content="Replace" Height="30" Width="80" Margin="5" 
                    Name="ReplaceButton"
                    Grid.Row="1"/>
            <Button Content="Clear" Height="30" Width="80" Margin="5" 
                    Name="ClearButton"
                    Grid.Column="1" Grid.Row="1"/>
        </Grid>

        <ListBox Name="ListName" ItemsSource="{Binding Persons}" Height="150" Width="200" Margin="5">
            
            <!-- Sử dụng thư viện Iteractivity Microsoft Expression Blend SDK 
            để tương tác với các event -->
            <!--<i:Interaction.Triggers>
                <i:EventTrigger EventName="MouseDoubleClick">
                    <i:InvokeCommandAction Command="{Binding DeleteCommand}"
                                           CommandParameter="{Binding SelectedItem, ElementName=ListName}">
                    </i:InvokeCommandAction>
                </i:EventTrigger>-->
                <!--<i:EventTrigger EventName="Click">
                    <i:InvokeCommandAction Command="{Binding DeleteCommand}"
                                           CommandParameter="{Binding SelectedItem, ElementName=ListName}">
                        
                    </i:InvokeCommandAction>
                </i:EventTrigger>
            </i:Interaction.Triggers>-->

            <ListBox.ItemTemplate>
                <DataTemplate>
                    <DockPanel>
                        <Button Content="X" Width="20" Height="20"
                                Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}"
                                Command="{Binding ElementName=ListName, Path=DataContext.DeleteCommand}"
                                CommandParameter="{Binding SelectedItem, ElementName=ListName}">
                        </Button>
                        <TextBlock Text="{Binding Name}" Margin="5, 3, 0, 0"/>
                    </DockPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        
        </ListBox>
    </StackPanel>
</Window>

PersonViewModel.cs

using MVVM_ListView.Models;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;

namespace MVVM_ListView.ViewModels
{
    public class PersonViewModel
    {
        public ObservableCollection<Person> Persons { get; set; }
        public ICommand DeleteCommand { get; set; }
        public ICommand AddCommand { get; set; }

        public PersonViewModel()
        {
            Persons = new ObservableCollection<Person>
            {
                new Person{Name = "Nguyen Duc Anh"},
                new Person{Name = "Nguyen Hoang Quynh Anh"},
                new Person{Name = "Nguyen Van An"},
                new Person{Name = "Mai Thanh Binh"},
                new Person{Name = "Silver Ben Spear"},
            };

            AddCommand = new RelayCommand<string>((s) => true, (s) => Persons.Add(new Person { Name = s }));
            DeleteCommand = new RelayCommand<Person>((p) => p != null, (p) => Persons.Remove(p));
        }  
    }
}