WPF&C#超市管理系统（3）商品管理 - 实践

超市管理系统

• • 6. 商品管理
  • • 6.1 添加商品
    • 6.1 商品管理主界面
    • 6.3 修改商品

---

6. 商品管理

• 将前文中的GoodsView全部改成和数据库一致的ProductView
• 新增枚举类型商品类型ProductType.cs

namespace 超市管理系统.Enums
{
public enum ProductType
{
水果类,
休闲食品类,
粮油类,
饮料类,
日用品
}
}

• 新增枚举类型商品单位UnitType.cs

namespace 超市管理系统.Entity
{
public enum UnitType
{
斤,
包,
瓶,
米,
个,
只,
桶
}
}

6.1 添加商品

• 将数据库Product表的Category从int改为nvarchar(50)，在Visual Studio中删掉Product表并从模型更新新表
• 新增AddProductView.xaml，复用AddCustomerView.xaml并修改，新增加ImageSource属性和上传图片的SelectImageCommand命令。
• AddCustomerViewModel内增加SupplierList属性、SupplierList属性、supplierProvider字段，supplierProvider字段用于添加商品界面初次打开时加载当前现有供应商，并赋值给SupplierList属性，SupplierList属性为Combox的当前选择项。
• 单价虽然为double类型，但是输入框中无法输入小数点，需要将UpdateSourceTrigger设置为LostFocus，因为PropertyChanged是立即更新，不认小数点。而失去焦点时更新可以有小数点。

<Window x:Class="超市管理系统.View.AddProductView"
  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:超市管理系统.View"
  mc:Ignorable="d"
  xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
  WindowStartupLocation="CenterScreen"
  DataContext="{Binding Source={StaticResource Locator}, Path=AddProductViewModel}"
  Title="商品管理" Height="450" Width="650">
<
i:Interaction.Triggers>
<
  i:EventTrigger EventName ="Loaded">
<
  i:InvokeCommandAction Command="{Binding LoadedCommand}" CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
<RowDefinition/>
<RowDefinition Height="auto"/>
</Grid.RowDefinitions>
<Grid Grid.Row="0" Height="50" Background="{Binding AppData.Background}">
<!--TextBlock设置height时，VerticalAlignment不生效，此地设置给grid-->
  <TextBlock Text="商品管理" FontSize="24" Foreground="White" VerticalAlignment="Center" HorizontalAlignment="Center"/>
</Grid>
  <Grid Grid.Row="1">
  <Grid.ColumnDefinitions>
    <ColumnDefinition/>
    <ColumnDefinition/>
  </Grid.ColumnDefinitions>
    <StackPanel Grid.Row="0" Margin="10" HorizontalAlignment="Center" >
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="供应商：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <ComboBox ItemsSource="{Binding SupplierList}" SelectedItem="{Binding Supplier}" DisplayMemberPath="Name" MinWidth="200"/>
    </StackPanel>
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="单 位：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <ComboBox ItemsSource="{Binding Product.Units}" SelectedItem="{Binding Product.Unit}" Width="200" />
    </StackPanel>
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="类 型：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <ComboBox ItemsSource="{Binding Product.ProductType}" SelectedItem="{Binding Product.Category}" Width="200" />
    </StackPanel>
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="商品名：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <TextBox Text="{Binding Product.Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="200" Height="30" VerticalAlignment="Center"/>
    </StackPanel>
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="单 价：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <TextBox Text="{Binding Product.Price, Mode=TwoWay, UpdateSourceTrigger=LostFocus}" Width="200" Height="30" VerticalAlignment="Center"/>
    </StackPanel>
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="库 存：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <TextBox Text="{Binding Product.Quantity, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="200" />
    </StackPanel>
  </StackPanel>
    <Grid Grid.Column="1" Margin="10" Background="#E2E2E2">
    <TextBlock Text="选择商品图片" HorizontalAlignment="Center" VerticalAlignment="Center"/>
      <Border Background="Transparent">
      <
      i:Interaction.Triggers>
      <
        i:EventTrigger EventName="MouseUp">
      <
        i:InvokeCommandAction Command="{Binding SelectImageCommand}"/>
    </i:EventTrigger>
  </i:Interaction.Triggers>
    <Image Source="{Binding ImageSource}">
  </Image>
</Border>
</Grid>
</Grid>
<StackPanel Grid.Row="2" Margin="10" Orientation="Horizontal" HorizontalAlignment="Right">
<Button x:Name="button1" Content="新增" Command="{Binding AddCommand}" CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}" Margin="10" Width="60" Height="25"/>
<Button x:Name="button2" Content="关闭" Command="{Binding ExitCommand}" CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}" Margin="10" Width="60" Height="25"/>
</StackPanel>
</Grid>
</Window>

• AddCustomerViewModel.cs包含属性由下拉框的供应商列表、单位、类型、商品名、单价、库存，以及当前供应商等内容，实现代码如下：
• 注意需要为新增按钮增加Product.SupplierId = Supplier.Id 将当前供应商Id传入

using GalaSoft.MvvmLight.Command;
using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Media.Imaging;
using 超市管理系统.Entity;
using 超市管理系统.Helper;
namespace 超市管理系统.ViewModel
{
public class AddProductViewModel
: ViewModelBase2
{
private ProductProvider productProvider = new ProductProvider();
private Product product;
public Product Product
{
get {
return product;
}
set
{
product = value;
RaisePropertyChanged();
}
}
private SupplierProvider supplierProvider = new SupplierProvider();
private List<Supplier> supplierList = new List<Supplier>();
  public List<Supplier> SupplierList
    {
    get {
    return supplierList;
    }
    set {
    supplierList = value;
    RaisePropertyChanged();
    }
    }
    private Supplier supplier;
    public Supplier Supplier
    {
    get {
    return supplier;
    }
    set
    {
    supplier = value;
    RaisePropertyChanged();
    }
    }
    #region commands
    public RelayCommand<Window> LoadedCommand
      {
      get
      {
      return new RelayCommand<Window>((view) =>
        {
        Product = new Product();
        SupplierList = supplierProvider.GetAll();
        ImageSource = null;
        Supplier = null;
        });
        }
        }
        public RelayCommand<Window> AddCommand
          {
          get
          {
          return new RelayCommand<Window>((view) =>
            {
            if (string.IsNullOrEmpty(Product.Name))
            {
            MessageBox.Show("姓名不能为空！");
            return;
            }
            Product.SupplierId = Supplier.Id;
            //将当前供应商Id传入
            Product.InsertDate = DateTime.Now;
            int count = productProvider.Insert(Product);
            if (count >
            0)
            {
            MessageBox.Show("操作成功！");
            }
            view.DialogResult = true;
            view.Close();
            });
            }
            }
            //当前商品图片
            private BitmapImage imageSourece;
            public BitmapImage ImageSource
            {
            get
            {
            return imageSourece;
            }
            set
            {
            imageSourece = value;
            RaisePropertyChanged();
            }
            }
            public RelayCommand<Window> SelectImageCommand
              {
              get
              {
              return new RelayCommand<Window>((view) =>
                {
                OpenFileDialog openFileDialog = new OpenFileDialog();
                //对话框标题
                openFileDialog.Title = "选择图片";
                //设置文件类型
                openFileDialog.Filter = "图片文件(*.jpg)|*.jpg|所有文件(*.*)|*.*";
                //默认文件顺序
                openFileDialog.FilterIndex = 1;
                //不可多选
                openFileDialog.Multiselect = false;
                //记忆上次打开目录
                openFileDialog.RestoreDirectory = true;
                if (openFileDialog.ShowDialog().Value == true)
                {
                string fileName = openFileDialog.FileName;
                ImageSource = new BitmapImage(new Uri(fileName));
                product.Image = ImageHelper.GetImageString(fileName);
                //测试转换是否正常
                var s = ImageHelper.GetBitmapImage(product.Image);
                ImageSource = s;
                }
                });
                }
                }
                public RelayCommand<Window> ExitCommand
                  {
                  get
                  {
                  return new RelayCommand<Window>((view) =>
                    {
                    Product = new Product();
                    });
                    }
                    }
                    #endregion
                    }
                    }

• 新增商品时添加的图片需要将图片转换为二进制流。在项目新建Helper文件夹，增加ImageHelper类包含函数GetImageString获取图片二进制流和GetBitmapImage二进制流转化为图片。

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Media.Imaging;
namespace 超市管理系统.Helper
{
public class ImageHelper
{
/// <summary>
  /// 获取图片的二进制流
/// </summary>
/// <param name="fileName"></param>
public static string GetImageString(string fileName)
{
try
{
FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read);
byte[] buffer = new byte[fileStream.Length];
fileStream.Read(buffer, 0, buffer.Length);
//从fileStream中读取数据，写入buffer中
return Convert.ToBase64String(buffer);
}
catch (Exception e)
{
MessageBox.Show(e.Message);
return string.Empty;
}
}
/// <summary>
  /// 二进制流转换成图片资源
/// </summary>
/// <param name="fileName"></param>
/// <returns></returns>
public static BitmapImage GetBitmapImage(string _buffer)
{
BitmapImage image = new BitmapImage();
try
{
byte[] buffer = Convert.FromBase64String(_buffer);
MemoryStream stream = new MemoryStream(buffer, 0, buffer.Length);
stream.Write(buffer, 0, buffer.Length);
stream.Position = 0;
image.BeginInit();
image.CacheOption = BitmapCacheOption.OnLoad;
image.StreamSource = stream;
image.EndInit();
image.Freeze();
return image;
}
catch (Exception e)
{
MessageBox.Show(e.Message);
return image;
}
}
}
}

6.1 商品管理主界面

• ProductView.xaml内容复用CustomerView.xaml并将Customer修改为Product，将绑定的属性改为Product属性
• 通过Image.ToolTip将鼠标悬停可实现图片放大

<UserControl x:Class="超市管理系统.View.ProductView"
  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:local="clr-namespace:超市管理系统.View" xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
  mc:Ignorable="d"
  Background="{Binding AppData.Background}"
  DataContext="{Binding Source={StaticResource Locator}, Path=ProductViewModel}"
  d:DesignHeight="450" d:DesignWidth="800">
<
i:Interaction.Triggers>
<
  i:EventTrigger EventName ="Loaded">
<
  i:InvokeCommandAction Command="{Binding LoadedCommand}" CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=UserControl}}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="40"/>
<RowDefinition/>
</Grid.RowDefinitions>
<Border BorderBrush="#22304B" BorderThickness="0 0 0 1">
<TextBlock Text="商品管理" VerticalAlignment="center" Margin="5 0 0 0" Foreground="{Binding AppData.Foreground}" FontSize="16"/>
</Border>
<Grid Grid.Row="1">
<Grid.RowDefinitions>
  <RowDefinition/>
  <RowDefinition Height="auto"/>
</Grid.RowDefinitions>
  <DataGrid ItemsSource="{Binding ProductList}"
  SelectedItem="{Binding SelectedProduct}"
  Style="{StaticResource DataGridStyle
}">
<DataGrid.Columns>
  <!--普通写法-->
    <!--<DataGridTextColumn Width="auto" Binding="{Binding Id}" Header="序号"/>
    <DataGridTextColumn Width="auto" Binding="{Binding Name}" Header="姓名"/>
    <DataGridTextColumn Width="auto" Binding="{Binding Telephone}" Header="电话"/>
    <DataGridTextColumn Width="auto" Binding="{Binding Address}" Header="地址"/>-->
    <!--数据模板写法-->
        <DataGridTemplateColumn Width="auto" Header="序号">
        <DataGridTemplateColumn.CellTemplate>
          <DataTemplate>
            <Grid>
                <TextBox Text="{Binding Id,Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource DataGridTextBoxStyle
              }"/>
            </Grid>
          </DataTemplate>
        </DataGridTemplateColumn.CellTemplate>
      </DataGridTemplateColumn>
        <DataGridTemplateColumn Width="auto" Header="商品名称">
        <DataGridTemplateColumn.CellTemplate>
          <DataTemplate>
            <Grid>
              <TextBox Text="{Binding Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
            </Grid>
          </DataTemplate>
        </DataGridTemplateColumn.CellTemplate>
      </DataGridTemplateColumn>
        <DataGridTemplateColumn Width="auto" Header="商品图片">
        <DataGridTemplateColumn.CellTemplate>
          <DataTemplate>
            <Grid>
                <Image Source="{Binding BitmapImage}" >
                <Image.ToolTip>
                  <Grid>
                    <Image Source="{Binding BitmapImage}"/>
                  </Grid>
                </Image.ToolTip>
              </Image>
            </Grid>
          </DataTemplate>
        </DataGridTemplateColumn.CellTemplate>
      </DataGridTemplateColumn>
        <DataGridTemplateColumn Width="auto" Header="单价">
        <DataGridTemplateColumn.CellTemplate>
          <DataTemplate>
            <Grid>
                <TextBox Text="{Binding Price, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource DataGridTextBoxStyle
                }" HorizontalAlignment="Left"/>
            </Grid>
          </DataTemplate>
        </DataGridTemplateColumn.CellTemplate>
      </DataGridTemplateColumn>
        <DataGridTemplateColumn Width="auto" Header="单位">
        <DataGridTemplateColumn.CellTemplate>
          <DataTemplate>
            <Grid>
                <TextBox Text="{Binding Unit, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource DataGridTextBoxStyle
                }" HorizontalAlignment="Left"/>
            </Grid>
          </DataTemplate>
        </DataGridTemplateColumn.CellTemplate>
      </DataGridTemplateColumn>
        <DataGridTemplateColumn Width="auto" Header="分类">
        <DataGridTemplateColumn.CellTemplate>
          <DataTemplate>
            <Grid>
                <TextBox Text="{Binding Category, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource DataGridTextBoxStyle
                }" HorizontalAlignment="Left"/>
            </Grid>
          </DataTemplate>
        </DataGridTemplateColumn.CellTemplate>
      </DataGridTemplateColumn>
        <DataGridTemplateColumn Width="auto" Header="单位">
        <DataGridTemplateColumn.CellTemplate>
          <DataTemplate>
            <Grid>
                <TextBox Text="{Binding Quantity, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource DataGridTextBoxStyle
                }" HorizontalAlignment="Left"/>
            </Grid>
          </DataTemplate>
        </DataGridTemplateColumn.CellTemplate>
      </DataGridTemplateColumn>
        <DataGridTemplateColumn Width="auto" Header="日期">
        <DataGridTemplateColumn.CellTemplate>
          <DataTemplate>
            <Grid>
                <TextBox Text="{Binding InsertDate, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource DataGridTextBoxStyle
                }" HorizontalAlignment="Left"/>
            </Grid>
          </DataTemplate>
        </DataGridTemplateColumn.CellTemplate>
      </DataGridTemplateColumn>
    </DataGrid.Columns>
  </DataGrid>
    <Grid Grid.Row="1">
    <Grid.ColumnDefinitions>
      <ColumnDefinition/>
      <ColumnDefinition/>
    </Grid.ColumnDefinitions>
      <StackPanel Grid.Column="0" Margin="0 5 5 5" Orientation="Horizontal" HorizontalAlignment="Left" VerticalAlignment="Center">
      <TextBlock Text="当前商品：" Margin="0 0 10 0" Foreground="White" Width="auto" />
      <TextBlock Text="{Binding SelectedProduct.Name}" Foreground="White" Width="auto"/>
    </StackPanel>
      <StackPanel Grid.Column="1" Margin="0 5 5 5" Orientation="Horizontal" HorizontalAlignment="Right">
      <Button Content="新增商品" Command="{Binding OpenAddViewCommand}" Margin="0 0 10 0" Width="80" Height="25"/>
      <Button Content="删除商品" Command="{Binding DeleteCommand}" Margin="0 0 10 0" Width="80" Height="25"/>
      <Button Content="修改" Command="{Binding EditCommand}" Width="80" Margin="0 0 10 0" Height="25"/>
      <Button Content="保存" Command="{Binding SaveCommand}" Width="80" Margin="0 0 10 0" Height="25"/>
    </StackPanel>
  </Grid>
</Grid>
</Grid>
</UserControl>

• ProductViewModel.cs内实现代码如下：

using CommonServiceLocator;
using GalaSoft.MvvmLight.Command;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using 超市管理系统.Entity;
using 超市管理系统.View;
namespace 超市管理系统.ViewModel
{
public class ProductViewModel
: ViewModelBase2
{
private ProductProvider productProvider = new ProductProvider();
private List<Product> productList = new List<Product>();
  public List<Product> ProductList
    {
    get {
    return productList;
    }
    set
    {
    productList = value;
    RaisePropertyChanged();
    }
    }
    //当前选中的顾客实体
    private Product selectedProduct;
    public Product SelectedProduct
    {
    get {
    return selectedProduct;
    }
    set
    {
    selectedProduct = value;
    RaisePropertyChanged();
    }
    }
    #region commands
    /// <summary>
      /// 加载所有供应商
    /// </summary>
    public RelayCommand<UserControl> LoadedCommand
      {
      get
      {
      return new RelayCommand<UserControl>((view) =>
        {
        ProductList = productProvider.GetAll();
        });
        }
        }
        public RelayCommand<UserControl> OpenAddViewCommand
          {
          get
          {
          return new RelayCommand<UserControl>((view) =>
            {
            AddProductView addProductView = new AddProductView();
            if (addProductView.ShowDialog().Value == true)
            {
            ProductList = productProvider.GetAll();
            }
            });
            }
            }
            public RelayCommand<UserControl> DeleteCommand
              {
              get
              {
              return new RelayCommand<UserControl>((view) =>
                {
                if (SelectedProduct == null) {
                return;
                }
                if (Dialog.Show() == true)
                {
                var count = productProvider.Delete(SelectedProduct);
                if (count >
                0)
                {
                MessageBox.Show("删除成功");
                ProductList = productProvider.GetAll();
                }
                }
                });
                }
                }
                public RelayCommand<UserControl> SaveCommand
                  {
                  get
                  {
                  return new RelayCommand<UserControl>((view) =>
                    {
                    var count = productProvider.Save();
                    if (count >
                    0)
                    {
                    MessageBox.Show("保存成功");
                    ProductList = productProvider.GetAll();
                    }
                    });
                    }
                    }
                    public RelayCommand<Window> EditCommand
                      {
                      get
                      {
                      return new RelayCommand<Window>((view) =>
                        {
                        if (SelectedProduct == null) {
                        return;
                        }
                        var vm = ServiceLocator.Current.GetInstance<EditProductViewModel>();
                          vm.Product = SelectedProduct;
                          EditProductView editProductView = new EditProductView();
                          if (editProductView.ShowDialog().Value == true)
                          {
                          ProductList = productProvider.GetAll();
                          }
                          });
                          }
                          }
                          #endregion
                          }
                          }

6.3 修改商品

• 新增EditProductView.xaml，复用EditCustomerView.xaml并修改，包含属性由下拉框的供应商列表、单位、类型、商品名、单价、库存，以及当前供应商等内容。

<Window x:Class="超市管理系统.View.EditProductView"
  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:超市管理系统.View"
  xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
  mc:Ignorable="d" WindowStartupLocation="CenterScreen"
  DataContext="{Binding Source={StaticResource Locator}, Path=EditProductViewModel}"
  Title="修改商品" Height="450" Width="650">
<
i:Interaction.Triggers>
<
  i:EventTrigger EventName ="Loaded">
<
  i:InvokeCommandAction Command="{Binding LoadedCommand}" CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
<RowDefinition/>
<RowDefinition Height="auto"/>
</Grid.RowDefinitions>
<Grid Grid.Row="0" Height="50" Background="{Binding AppData.Background}">
<!--TextBlock设置height时，VerticalAlignment不生效，此地设置给grid-->
  <TextBlock Text="修改商品" FontSize="24" Foreground="White" VerticalAlignment="Center" HorizontalAlignment="Center"/>
</Grid>
  <Grid Grid.Row="1">
  <Grid.ColumnDefinitions>
    <ColumnDefinition/>
    <ColumnDefinition/>
  </Grid.ColumnDefinitions>
    <StackPanel Grid.Row="0" Margin="10" HorizontalAlignment="Center" >
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="供应商：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <ComboBox ItemsSource="{Binding SupplierList}" SelectedItem="{Binding Supplier}" DisplayMemberPath="Name" MinWidth="200"/>
    </StackPanel>
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="单 位：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <ComboBox ItemsSource="{Binding Product.Units}" SelectedItem="{Binding Product.Unit}" Width="200" />
    </StackPanel>
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="类 型：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <ComboBox ItemsSource="{Binding Product.ProductType}" SelectedItem="{Binding Product.Category}" Width="200" />
    </StackPanel>
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="商品名：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <TextBox Text="{Binding Product.Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="200" Height="30" VerticalAlignment="Center"/>
    </StackPanel>
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="单 价：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <TextBox Text="{Binding Product.Price, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="200" Height="30" VerticalAlignment="Center"/>
    </StackPanel>
      <StackPanel Orientation="Horizontal" Height="30" Margin="0 5 0 10">
      <TextBlock Text="库 存：" Width="70" FontSize="18" VerticalAlignment="Center"/>
      <TextBox Text="{Binding Product.Quantity, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="200" />
    </StackPanel>
  </StackPanel>
    <Grid Grid.Column="1" Margin="10" Background="#E2E2E2">
    <TextBlock Text="选择商品图片" HorizontalAlignment="Center" VerticalAlignment="Center"/>
      <Border Background="Transparent">
      <
      i:Interaction.Triggers>
      <
        i:EventTrigger EventName="MouseUp">
      <
        i:InvokeCommandAction Command="{Binding SelectImageCommand}"/>
    </i:EventTrigger>
  </i:Interaction.Triggers>
    <Image Source="{Binding ImageSource}">
  </Image>
</Border>
</Grid>
</Grid>
<StackPanel Grid.Row="2" Margin="10" Orientation="Horizontal" HorizontalAlignment="Right">
<Button x:Name="button1" Content="确定" Command="{Binding OKCommand}" CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}" Margin="10" Width="60" Height="25"/>
<Button x:Name="button2" Content="关闭" Command="{Binding ExitCommand}" CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}" Margin="10" Width="60" Height="25"/>
</StackPanel>
</Grid>
</Window>

• EditProductViewModel.cs复用 AddProductViewModel.cs内的代码与命令。在OK按钮的命令中需要Product.SupplierId = Supplier.Id; 将当前供应商Id传入

using GalaSoft.MvvmLight.Command;
using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using 超市管理系统.Entity;
using 超市管理系统.Helper;
namespace 超市管理系统.ViewModel
{
public class EditProductViewModel
: ViewModelBase2
{
private ProductProvider productProvider = new ProductProvider();
private Product product;
public Product Product
{
get {
return product;
}
set
{
product = value;
RaisePropertyChanged();
}
}
private SupplierProvider supplierProvider = new SupplierProvider();
private List<Supplier> supplierList = new List<Supplier>();
  public List<Supplier> SupplierList
    {
    get {
    return supplierList;
    }
    set
    {
    supplierList = value;
    RaisePropertyChanged();
    }
    }
    private Supplier supplier;
    public Supplier Supplier
    {
    get {
    return supplier;
    }
    set
    {
    supplier = value;
    RaisePropertyChanged();
    }
    }
    //当前商品图片
    private BitmapImage imageSourece;
    public BitmapImage ImageSource
    {
    get
    {
    return imageSourece;
    }
    set
    {
    imageSourece = value;
    RaisePropertyChanged();
    }
    }
    #region commands
    public RelayCommand<Window> LoadedCommand
      {
      get
      {
      return new RelayCommand<Window>((view) =>
        {
        ImageSource = Product.BitmapImage;
        SupplierList = supplierProvider.GetAll();
        Supplier = SupplierList.FirstOrDefault(t => t.Id == Product.SupplierId);
        });
        }
        }
        public RelayCommand<Window> SelectImageCommand
          {
          get
          {
          return new RelayCommand<Window>((view) =>
            {
            OpenFileDialog openFileDialog = new OpenFileDialog();
            //对话框标题
            openFileDialog.Title = "选择图片";
            //设置文件类型
            openFileDialog.Filter = "图片文件(*.jpg)|*.jpg|所有文件(*.*)|*.*";
            //默认文件顺序
            openFileDialog.FilterIndex = 1;
            //不可多选
            openFileDialog.Multiselect = false;
            //记忆上次打开目录
            openFileDialog.RestoreDirectory = true;
            if (openFileDialog.ShowDialog().Value == true)
            {
            string fileName = openFileDialog.FileName;
            ImageSource = new BitmapImage(new Uri(fileName));
            product.Image = ImageHelper.GetImageString(fileName);
            //测试转换是否正常
            //var s = ImageHelper.GetBitmapImage(product.Image);
            //ImageSource = s;
            }
            });
            }
            }
            public RelayCommand<Window> OKCommand
              {
              get
              {
              return new RelayCommand<Window>((view) =>
                {
                if (string.IsNullOrEmpty(Product.Name))
                {
                MessageBox.Show("姓名不能为空！");
                return;
                }
                Product.SupplierId = Supplier.Id;
                //将当前供应商Id传入
                //Product.InsertDate = DateTime.Now;
                int count = productProvider.Update(Product);
                if (count >
                0)
                {
                MessageBox.Show("操作成功！");
                }
                view.DialogResult = true;
                view.Close();
                });
                }
                }
                public RelayCommand<Window> ExitCommand
                  {
                  get
                  {
                  return new RelayCommand<Window>((view) =>
                    {
                    Product = new Product();
                    });
                    }
                    }
                    #endregion
                    }
                    }