C#中WVVM的使用

学习WVVM模式，设计一个简单的菜单显示和选择时显示个数的一个例子。

最终效果：

所建文件结构如下：

MenuModel:菜品属性－名称和价格

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace WpfApplication2.Model
{
   public class MenuModel
    {
        public string Name { get; set; }
        public string Price { get; set; }

    }
}

DelegateCommend:命令属性

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Input;

namespace WpfApplication2.Model
{
   public class DelegateCommend:ICommand
    {
        public Action<object> ExecuteAction { get; set; }
        public Func<object,bool> CanExecuteFunc { get; set; }
        public bool CanExecute(object parameter)
        {
            if (CanExecuteFunc==null)
            return true;
            return CanExecuteFunc(parameter);
        }

        public event EventHandler CanExecuteChanged;

        public void Execute(object parameter)
        {
            if (ExecuteAction == null)
                return;
            ExecuteAction(parameter);
        }
    }
}

DishService:初始化菜品集合

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using WpfApplication2.Model;

namespace WpfApplication2.Servers
{
   public class DishService
    {
       public List<ListMenuModel> GetDishes()
       {
           List<ListMenuModel> list = new List<ListMenuModel>();
           list.Add(new ListMenuModel {Dishes= new MenuModel{Name = "黄瓜", Price = "8" },IsSelected=false});
           list.Add(new ListMenuModel { Dishes = new MenuModel { Name = "酸菜", Price = "5" }, IsSelected = false });
           list.Add(new ListMenuModel { Dishes = new MenuModel { Name = "拉皮", Price = "7" }, IsSelected = false });
           list.Add(new ListMenuModel { Dishes = new MenuModel { Name = "凉粉", Price = "6" }, IsSelected = false });
           list.Add(new ListMenuModel { Dishes = new MenuModel { Name = "豆芽", Price = "3" }, IsSelected = false });
           list.Add(new ListMenuModel { Dishes = new MenuModel { Name = "京皮", Price = "5" }, IsSelected = false });
           return list;
       }
    }
}

ListMenuModel：界面中菜品和选择复选框的viewmodel，具有通知功能

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;

namespace WpfApplication2.Model
{
    public class ListMenuModel:INotifyPropertyChanged
    {
        public MenuModel Dishes { get; set; }
        private bool isSelected;

        public bool IsSelected
        {
            get { return isSelected; }
            set { isSelected = value;
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs("IsSelected"));
            }
        }
        

        public event PropertyChangedEventHandler PropertyChanged;
    }
}

MainViews：界面所有数据绑定的源

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using WpfApplication2.Model;
using WpfApplication2.Servers;

namespace WpfApplication2.Views
{
   public class MainViews:INotifyPropertyChanged
    {
        public DelegateCommend SelectCmd { get; set; }

        private List<ListMenuModel> dishes;

        public List<ListMenuModel> Dishes
        {
            get { return dishes; }
            set { dishes = value;
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs("Dishes"));
            }
        }

        private int count;

        public int Count
        {
            get { return count; }
            set { count = value;
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs("Count"));
            }
        }

       
       public MainViews()
       {
           Dishes = (new DishService()).GetDishes();

           SelectCmd = new DelegateCommend();

           SelectCmd.ExecuteAction = x =>
           {
               this.Count = Dishes.Where(n => n.IsSelected == true).Count();
           };
       }

       public event PropertyChangedEventHandler PropertyChanged;
    }

}

MainWindow.xaml：界面

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Grid>

        <Border CornerRadius="6" Background="Yellow" BorderThickness="3" BorderBrush="Orange" Margin="0,0,0.4,-0.2" Grid.RowSpan="3">
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="auto"/>
                    <RowDefinition Height="*"/>
                    <RowDefinition Height="auto"/>
                </Grid.RowDefinitions>
                <Border BorderThickness="1" BorderBrush="Orange" Padding="4" CornerRadius="6">
                    <StackPanel>
                        <StackPanel.Effect>
                            <DropShadowEffect Color="LightBlue"></DropShadowEffect>
                        </StackPanel.Effect>
                        <TextBlock Text="欢迎光临！" FontSize="30"></TextBlock>
                    </StackPanel>
                </Border>

                <DataGrid Name="dishGrid" Grid.Row="1" AutoGenerateColumns="False" CanUserAddRows="False" CanUserDeleteRows="False" GridLinesVisibility="None">
                    <DataGrid.Columns>
                        <DataGridTextColumn Header="菜名" Binding="{Binding Dishes.Name}"></DataGridTextColumn>
                        <DataGridTextColumn Header="价格" Binding="{Binding Dishes.Price}"></DataGridTextColumn>
                        <DataGridTemplateColumn >
                            <DataGridTemplateColumn.CellTemplate>
                                <DataTemplate>
                                    <CheckBox IsChecked="{Binding IsSelected,UpdateSourceTrigger=PropertyChanged}" Command="{Binding DataContext.SelectCmd,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type Window}}}"></CheckBox>
                                </DataTemplate>
                            </DataGridTemplateColumn.CellTemplate>
                        </DataGridTemplateColumn>
                    </DataGrid.Columns>

                </DataGrid>


                <StackPanel Grid.Row="2" HorizontalAlignment="Right" Orientation="Horizontal" Margin="5">
                    <TextBlock Text="共计" FontSize="16 "></TextBlock>
                    <TextBox IsReadOnly="True" Width="50" Text="{Binding Count}"></TextBox>
                    <Button Content="下单" Height="24"  Width="120"></Button>
                </StackPanel>
            </Grid>
        </Border>
    </Grid>
</Window>

其C#代码如下：设置数据及绑定

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using WpfApplication2.Model;
using WpfApplication2.Servers;
using WpfApplication2.Views;
namespace WpfApplication2
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            MainViews mw = new MainViews();

            this.DataContext = mw;
            dishGrid.ItemsSource = mw.Dishes;

        }
    }
}