C# 使用MVVM在Windows Phone 8.1应用程序上进行双向绑定_C#_Xaml_Mvvm_Binding_Windows Phone 8.1

C# 使用MVVM在Windows Phone 8.1应用程序上进行双向绑定

c# xaml mvvm binding windows-phone-8.1

C# 使用MVVM在Windows Phone 8.1应用程序上进行双向绑定,c#,xaml,mvvm,binding,windows-phone-8.1,C#,Xaml,Mvvm,Binding,Windows Phone 8.1,我正在使用MVVM开发一个销售管理系统，但在保存视图中输入的数据时遇到问题。我假设双向绑定意味着在视图上输入的所有值都应该传递给ViewModel，反之亦然，对吗查看： <TextBox x:Name="NameText" Grid.ColumnSpan="2" Grid.Row="2" Header="Nombre:" Style="{StaticResource Register

我正在使用MVVM开发一个销售管理系统，但在保存视图中输入的数据时遇到问题。我假设双向绑定意味着在视图上输入的所有值都应该传递给ViewModel，反之亦然，对吗

查看：

 <TextBox x:Name="NameText"
             Grid.ColumnSpan="2"
             Grid.Row="2"
             Header="Nombre:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Name, Mode=TwoWay}"/>
    <ComboBox x:Name="UnitCombo"
              Grid.Row="3"
              Grid.ColumnSpan="2"
              Header="Unidad:"
              PlaceholderText="Elige la medida"
              Style="{StaticResource RegisterComboBoxStyle}"
              ItemsSource="{Binding Path=UnitsSource, Mode=OneWay}"
              SelectedValue="{Binding SelectedUnit, Mode=TwoWay}"/>
    <TextBox x:Name="CostText"
             Grid.Column="0"
             Grid.Row="4"
             Header="Costo:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Cost, Mode=TwoWay}"/>
    <TextBox x:Name="PriceText"
             Grid.Column="1"
             Grid.Row="4"
             Header="Precio:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Price, Mode=TwoWay}"/>
    <ToggleSwitch x:Name="ActiveToggle"
                  Grid.Column="1"
                  Grid.Row="5"
                  Style="{StaticResource RegisterToggleSwithStyle}"
                  IsOn="{Binding Product.Active, Mode=TwoWay}"/>

namespace BillingShop.ViewModel
{
    public class ProductListViewModel : ViewModelBase, INavigable
    {
        public ObservableCollection<ProductViewModel> Items { get; private set; }
    private DelegateCommand _saveProduct;
    public bool IsUpdating { get; set; }
    public ProductViewModel Product { get; set; }
    public Visibility UpdatingVisibility => (IsUpdating || Items == null || Items.Count == 0) ? Visibility.Visible : Visibility.Collapsed;

    public ProductListViewModel()
    {
        if (IsInDesignMode)
        {
            return;
        }
        _saveProduct = new DelegateCommand(SaveCommand_Executed);
    }

    #region Product Members

    private string _unit;
    public string SelectedUnit
    {
        get { return _unit; }
        set
        {
            _unit = value;
            OnPropertyChanged();
        }
    }

    #endregion


    public IEnumerable<RegisteredUnits> UnitsSource => Enum.GetValues(typeof(RegisteredUnits)).Cast<RegisteredUnits>();

    public ICommand SaveCommand => _saveProduct;

    private void SaveCommand_Executed()
    {
        var product = new Product
        {
            Name = Product.Name,
            Unit = Product.Unit,
            Cost = Convert.ToDouble(Product.Cost),
            Price = Convert.ToDouble(Product.Price),
            Active = Convert.ToBoolean(Product.Active)
        };
        ProductManager.SaveProduct(product);
    }

    public void PopulateProductViewModel(ProductViewModel entry)
    {
        Product = entry;
        OnPropertyChanged("Product");
    }
    public Product GetProduct()
    {
        return Product?.GetProduct();
    }
}

public class ProductViewModel : ViewModelBase
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Unit { get; set; }
    public double Cost { get; set; }
    public double Price { get; set; }
    public bool Active { get; set; }
    public List<SalesDetails> SalesDetail { get; set; }

    public ProductViewModel()
    {
    }

    public ProductViewModel(Product item)
    {
        Update(item);
    }
    public void Update (Product item)
    {
        Id = item.ID;
        Name = item.Name;
        Unit = item.Unit;
        Cost = item.Cost;
        Price = item.Price;
        Active = item.Active;
        SalesDetail = item.SalesDetail;
    }

    public Product GetProduct()
    {
        return new Product
        {
            ID = Id,
            Name = Name,
            Unit = Unit,
            Cost = Cost,
            Price = Price,
            Active = Active,
            SalesDetail = SalesDetail
        };
    }
}

public class Product : IBusinessEntity
{
    /// <summary>
    /// Represents a Product.
    /// </summary>
    public Product()
    {
    }


    /// <summary>
    /// Get or sets the product identifier.
    /// </summary>
    [PrimaryKey, AutoIncrement]
    public int ID { get; set; }
    /// <summary>
    /// Get or sets the product name.
    /// </summary>
    [MaxLength(40)]
    public string Name { get; set; }
    /// <summary>
    /// Get or sets if the product can be measured in units or kilograms.
    /// </summary>
    public string Unit { get; set; }
    /// <summary>
    /// Get or sets the product cost.
    /// </summary>
    public double Cost { get; set; }
    /// <summary>
    /// Get or sets the product price.
    /// </summary>
    public double Price { get; set; }
    /// <summary>
    /// Get or sets the product state.
    /// </summary>
    public bool Active { get; set; }
    /// <summary>
    /// One-To-Many relationship with SalesDetails.
    /// </summary>
    [OneToMany(CascadeOperations = CascadeOperation.All)]
    public List<SalesDetails> SalesDetail { get; set; }


}

ProductListViewModel：

 <TextBox x:Name="NameText"
             Grid.ColumnSpan="2"
             Grid.Row="2"
             Header="Nombre:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Name, Mode=TwoWay}"/>
    <ComboBox x:Name="UnitCombo"
              Grid.Row="3"
              Grid.ColumnSpan="2"
              Header="Unidad:"
              PlaceholderText="Elige la medida"
              Style="{StaticResource RegisterComboBoxStyle}"
              ItemsSource="{Binding Path=UnitsSource, Mode=OneWay}"
              SelectedValue="{Binding SelectedUnit, Mode=TwoWay}"/>
    <TextBox x:Name="CostText"
             Grid.Column="0"
             Grid.Row="4"
             Header="Costo:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Cost, Mode=TwoWay}"/>
    <TextBox x:Name="PriceText"
             Grid.Column="1"
             Grid.Row="4"
             Header="Precio:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Price, Mode=TwoWay}"/>
    <ToggleSwitch x:Name="ActiveToggle"
                  Grid.Column="1"
                  Grid.Row="5"
                  Style="{StaticResource RegisterToggleSwithStyle}"
                  IsOn="{Binding Product.Active, Mode=TwoWay}"/>

namespace BillingShop.ViewModel
{
    public class ProductListViewModel : ViewModelBase, INavigable
    {
        public ObservableCollection<ProductViewModel> Items { get; private set; }
    private DelegateCommand _saveProduct;
    public bool IsUpdating { get; set; }
    public ProductViewModel Product { get; set; }
    public Visibility UpdatingVisibility => (IsUpdating || Items == null || Items.Count == 0) ? Visibility.Visible : Visibility.Collapsed;

    public ProductListViewModel()
    {
        if (IsInDesignMode)
        {
            return;
        }
        _saveProduct = new DelegateCommand(SaveCommand_Executed);
    }

    #region Product Members

    private string _unit;
    public string SelectedUnit
    {
        get { return _unit; }
        set
        {
            _unit = value;
            OnPropertyChanged();
        }
    }

    #endregion


    public IEnumerable<RegisteredUnits> UnitsSource => Enum.GetValues(typeof(RegisteredUnits)).Cast<RegisteredUnits>();

    public ICommand SaveCommand => _saveProduct;

    private void SaveCommand_Executed()
    {
        var product = new Product
        {
            Name = Product.Name,
            Unit = Product.Unit,
            Cost = Convert.ToDouble(Product.Cost),
            Price = Convert.ToDouble(Product.Price),
            Active = Convert.ToBoolean(Product.Active)
        };
        ProductManager.SaveProduct(product);
    }

    public void PopulateProductViewModel(ProductViewModel entry)
    {
        Product = entry;
        OnPropertyChanged("Product");
    }
    public Product GetProduct()
    {
        return Product?.GetProduct();
    }
}

public class ProductViewModel : ViewModelBase
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Unit { get; set; }
    public double Cost { get; set; }
    public double Price { get; set; }
    public bool Active { get; set; }
    public List<SalesDetails> SalesDetail { get; set; }

    public ProductViewModel()
    {
    }

    public ProductViewModel(Product item)
    {
        Update(item);
    }
    public void Update (Product item)
    {
        Id = item.ID;
        Name = item.Name;
        Unit = item.Unit;
        Cost = item.Cost;
        Price = item.Price;
        Active = item.Active;
        SalesDetail = item.SalesDetail;
    }

    public Product GetProduct()
    {
        return new Product
        {
            ID = Id,
            Name = Name,
            Unit = Unit,
            Cost = Cost,
            Price = Price,
            Active = Active,
            SalesDetail = SalesDetail
        };
    }
}

public class Product : IBusinessEntity
{
    /// <summary>
    /// Represents a Product.
    /// </summary>
    public Product()
    {
    }


    /// <summary>
    /// Get or sets the product identifier.
    /// </summary>
    [PrimaryKey, AutoIncrement]
    public int ID { get; set; }
    /// <summary>
    /// Get or sets the product name.
    /// </summary>
    [MaxLength(40)]
    public string Name { get; set; }
    /// <summary>
    /// Get or sets if the product can be measured in units or kilograms.
    /// </summary>
    public string Unit { get; set; }
    /// <summary>
    /// Get or sets the product cost.
    /// </summary>
    public double Cost { get; set; }
    /// <summary>
    /// Get or sets the product price.
    /// </summary>
    public double Price { get; set; }
    /// <summary>
    /// Get or sets the product state.
    /// </summary>
    public bool Active { get; set; }
    /// <summary>
    /// One-To-Many relationship with SalesDetails.
    /// </summary>
    [OneToMany(CascadeOperations = CascadeOperation.All)]
    public List<SalesDetails> SalesDetail { get; set; }


}

namespace BillingShop.ViewModel
{
公共类ProductListViewModel:ViewModelBase，不可用
{
公共可观测集合项{get；private set；}
私有DelegateCommand_saveProduct；
公共bool正在更新{get；set；}
公共产品视图模型产品{get；set；}
公共可见性更新可见性=>（IsUpdate | | Items==null | | Items.Count==0）？可见性。可见：可见性。折叠；
公共产品列表视图模型（）
{
如果（IsInDesignMode）
{
返回；
}
_saveProduct=新的DelegateCommand（SaveCommand_已执行）；
}
#地区产品成员
专用字符串单元；
公共字符串SelectedUnit
{
获取{return\u unit；}
设置
{
_单位=价值；
OnPropertyChanged（）；
}
}
#端区
public IEnumerable UnitsSource=>Enum.GetValues（typeof（RegisteredUnits））.Cast（）；
公共ICommand SaveCommand=>\u saveProduct；
私有void SaveCommand_Executed（）
{
var产品=新产品
{
Name=Product.Name，
单位=产品单位，
成本=换算成双倍（产品成本），
价格=转换为双倍（产品价格），
Active=Convert.ToBoolean（Product.Active）
};
ProductManager.SaveProduct（产品）；
}
public void PopulateProductViewModel（ProductViewModel条目）
{
产品=入口；
不动产变更（“产品”）；
}
公共产品
{
退货产品？.GetProduct（）；
}
}

}

产品视图模型：

 <TextBox x:Name="NameText"
             Grid.ColumnSpan="2"
             Grid.Row="2"
             Header="Nombre:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Name, Mode=TwoWay}"/>
    <ComboBox x:Name="UnitCombo"
              Grid.Row="3"
              Grid.ColumnSpan="2"
              Header="Unidad:"
              PlaceholderText="Elige la medida"
              Style="{StaticResource RegisterComboBoxStyle}"
              ItemsSource="{Binding Path=UnitsSource, Mode=OneWay}"
              SelectedValue="{Binding SelectedUnit, Mode=TwoWay}"/>
    <TextBox x:Name="CostText"
             Grid.Column="0"
             Grid.Row="4"
             Header="Costo:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Cost, Mode=TwoWay}"/>
    <TextBox x:Name="PriceText"
             Grid.Column="1"
             Grid.Row="4"
             Header="Precio:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Price, Mode=TwoWay}"/>
    <ToggleSwitch x:Name="ActiveToggle"
                  Grid.Column="1"
                  Grid.Row="5"
                  Style="{StaticResource RegisterToggleSwithStyle}"
                  IsOn="{Binding Product.Active, Mode=TwoWay}"/>

namespace BillingShop.ViewModel
{
    public class ProductListViewModel : ViewModelBase, INavigable
    {
        public ObservableCollection<ProductViewModel> Items { get; private set; }
    private DelegateCommand _saveProduct;
    public bool IsUpdating { get; set; }
    public ProductViewModel Product { get; set; }
    public Visibility UpdatingVisibility => (IsUpdating || Items == null || Items.Count == 0) ? Visibility.Visible : Visibility.Collapsed;

    public ProductListViewModel()
    {
        if (IsInDesignMode)
        {
            return;
        }
        _saveProduct = new DelegateCommand(SaveCommand_Executed);
    }

    #region Product Members

    private string _unit;
    public string SelectedUnit
    {
        get { return _unit; }
        set
        {
            _unit = value;
            OnPropertyChanged();
        }
    }

    #endregion


    public IEnumerable<RegisteredUnits> UnitsSource => Enum.GetValues(typeof(RegisteredUnits)).Cast<RegisteredUnits>();

    public ICommand SaveCommand => _saveProduct;

    private void SaveCommand_Executed()
    {
        var product = new Product
        {
            Name = Product.Name,
            Unit = Product.Unit,
            Cost = Convert.ToDouble(Product.Cost),
            Price = Convert.ToDouble(Product.Price),
            Active = Convert.ToBoolean(Product.Active)
        };
        ProductManager.SaveProduct(product);
    }

    public void PopulateProductViewModel(ProductViewModel entry)
    {
        Product = entry;
        OnPropertyChanged("Product");
    }
    public Product GetProduct()
    {
        return Product?.GetProduct();
    }
}

public class ProductViewModel : ViewModelBase
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Unit { get; set; }
    public double Cost { get; set; }
    public double Price { get; set; }
    public bool Active { get; set; }
    public List<SalesDetails> SalesDetail { get; set; }

    public ProductViewModel()
    {
    }

    public ProductViewModel(Product item)
    {
        Update(item);
    }
    public void Update (Product item)
    {
        Id = item.ID;
        Name = item.Name;
        Unit = item.Unit;
        Cost = item.Cost;
        Price = item.Price;
        Active = item.Active;
        SalesDetail = item.SalesDetail;
    }

    public Product GetProduct()
    {
        return new Product
        {
            ID = Id,
            Name = Name,
            Unit = Unit,
            Cost = Cost,
            Price = Price,
            Active = Active,
            SalesDetail = SalesDetail
        };
    }
}

public class Product : IBusinessEntity
{
    /// <summary>
    /// Represents a Product.
    /// </summary>
    public Product()
    {
    }


    /// <summary>
    /// Get or sets the product identifier.
    /// </summary>
    [PrimaryKey, AutoIncrement]
    public int ID { get; set; }
    /// <summary>
    /// Get or sets the product name.
    /// </summary>
    [MaxLength(40)]
    public string Name { get; set; }
    /// <summary>
    /// Get or sets if the product can be measured in units or kilograms.
    /// </summary>
    public string Unit { get; set; }
    /// <summary>
    /// Get or sets the product cost.
    /// </summary>
    public double Cost { get; set; }
    /// <summary>
    /// Get or sets the product price.
    /// </summary>
    public double Price { get; set; }
    /// <summary>
    /// Get or sets the product state.
    /// </summary>
    public bool Active { get; set; }
    /// <summary>
    /// One-To-Many relationship with SalesDetails.
    /// </summary>
    [OneToMany(CascadeOperations = CascadeOperation.All)]
    public List<SalesDetails> SalesDetail { get; set; }


}

公共类ProductViewModel:ViewModelBase
{
公共int Id{get；set；}
公共字符串名称{get；set；}
公共字符串单元{get；set；}
公共双成本{get；set；}
公共双价{get；set；}
公共bool活动{get；set；}
公共列表SalesDetail{get；set；}
公共产品视图模型（）
{
}
公共产品视图模型（产品项）
{
更新（项目）；
}
公共作废更新（产品项）
{
Id=item.Id；
名称=项目名称；
单位=项目。单位；
成本=项目成本；
价格=项目价格；
活动=项目。活动；
SalesDetail=item.SalesDetail；
}
公共产品
{
退回新产品
{
ID=ID，
Name=Name，
单位=单位，
成本=成本，
价格=价格，
活动=活动，
SalesDetail=SalesDetail
};
}
}

执行SaveProduct时，Product类显示为null，那么我的视图值呢？我的代码有什么问题

感谢所有帮助我的人，我将我的存储库链接放在这里，也许有人想深入了解我的代码：

编辑：这是我的产品类别：

 <TextBox x:Name="NameText"
             Grid.ColumnSpan="2"
             Grid.Row="2"
             Header="Nombre:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Name, Mode=TwoWay}"/>
    <ComboBox x:Name="UnitCombo"
              Grid.Row="3"
              Grid.ColumnSpan="2"
              Header="Unidad:"
              PlaceholderText="Elige la medida"
              Style="{StaticResource RegisterComboBoxStyle}"
              ItemsSource="{Binding Path=UnitsSource, Mode=OneWay}"
              SelectedValue="{Binding SelectedUnit, Mode=TwoWay}"/>
    <TextBox x:Name="CostText"
             Grid.Column="0"
             Grid.Row="4"
             Header="Costo:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Cost, Mode=TwoWay}"/>
    <TextBox x:Name="PriceText"
             Grid.Column="1"
             Grid.Row="4"
             Header="Precio:"
             Style="{StaticResource RegisterTextBoxStyle}"
             Text="{Binding Product.Price, Mode=TwoWay}"/>
    <ToggleSwitch x:Name="ActiveToggle"
                  Grid.Column="1"
                  Grid.Row="5"
                  Style="{StaticResource RegisterToggleSwithStyle}"
                  IsOn="{Binding Product.Active, Mode=TwoWay}"/>

namespace BillingShop.ViewModel
{
    public class ProductListViewModel : ViewModelBase, INavigable
    {
        public ObservableCollection<ProductViewModel> Items { get; private set; }
    private DelegateCommand _saveProduct;
    public bool IsUpdating { get; set; }
    public ProductViewModel Product { get; set; }
    public Visibility UpdatingVisibility => (IsUpdating || Items == null || Items.Count == 0) ? Visibility.Visible : Visibility.Collapsed;

    public ProductListViewModel()
    {
        if (IsInDesignMode)
        {
            return;
        }
        _saveProduct = new DelegateCommand(SaveCommand_Executed);
    }

    #region Product Members

    private string _unit;
    public string SelectedUnit
    {
        get { return _unit; }
        set
        {
            _unit = value;
            OnPropertyChanged();
        }
    }

    #endregion


    public IEnumerable<RegisteredUnits> UnitsSource => Enum.GetValues(typeof(RegisteredUnits)).Cast<RegisteredUnits>();

    public ICommand SaveCommand => _saveProduct;

    private void SaveCommand_Executed()
    {
        var product = new Product
        {
            Name = Product.Name,
            Unit = Product.Unit,
            Cost = Convert.ToDouble(Product.Cost),
            Price = Convert.ToDouble(Product.Price),
            Active = Convert.ToBoolean(Product.Active)
        };
        ProductManager.SaveProduct(product);
    }

    public void PopulateProductViewModel(ProductViewModel entry)
    {
        Product = entry;
        OnPropertyChanged("Product");
    }
    public Product GetProduct()
    {
        return Product?.GetProduct();
    }
}

public class ProductViewModel : ViewModelBase
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Unit { get; set; }
    public double Cost { get; set; }
    public double Price { get; set; }
    public bool Active { get; set; }
    public List<SalesDetails> SalesDetail { get; set; }

    public ProductViewModel()
    {
    }

    public ProductViewModel(Product item)
    {
        Update(item);
    }
    public void Update (Product item)
    {
        Id = item.ID;
        Name = item.Name;
        Unit = item.Unit;
        Cost = item.Cost;
        Price = item.Price;
        Active = item.Active;
        SalesDetail = item.SalesDetail;
    }

    public Product GetProduct()
    {
        return new Product
        {
            ID = Id,
            Name = Name,
            Unit = Unit,
            Cost = Cost,
            Price = Price,
            Active = Active,
            SalesDetail = SalesDetail
        };
    }
}

public class Product : IBusinessEntity
{
    /// <summary>
    /// Represents a Product.
    /// </summary>
    public Product()
    {
    }


    /// <summary>
    /// Get or sets the product identifier.
    /// </summary>
    [PrimaryKey, AutoIncrement]
    public int ID { get; set; }
    /// <summary>
    /// Get or sets the product name.
    /// </summary>
    [MaxLength(40)]
    public string Name { get; set; }
    /// <summary>
    /// Get or sets if the product can be measured in units or kilograms.
    /// </summary>
    public string Unit { get; set; }
    /// <summary>
    /// Get or sets the product cost.
    /// </summary>
    public double Cost { get; set; }
    /// <summary>
    /// Get or sets the product price.
    /// </summary>
    public double Price { get; set; }
    /// <summary>
    /// Get or sets the product state.
    /// </summary>
    public bool Active { get; set; }
    /// <summary>
    /// One-To-Many relationship with SalesDetails.
    /// </summary>
    [OneToMany(CascadeOperations = CascadeOperation.All)]
    public List<SalesDetails> SalesDetail { get; set; }


}

公共类产品：IBusinessEntity
{
/// 
///代表一种产品。
/// 
公共产品（）
{
}
/// 
///获取或设置产品标识符。
/// 
[主密钥，自动增量]
公共int ID{get；set；}
/// 
///获取或设置产品名称。
/// 
[MaxLength（40）]
公共字符串名称{get；set；}
/// 
///获取或设置产品是否可以单位或千克计量。
/// 
公共字符串单元{get；set；}
/// 
///获取或设置产品成本。
/// 
公共双成本{get；set；}
/// 
///获取或设置产品价格。
/// 
公共双价{get；set；}
/// 
///获取或设置产品状态。
/// 
公共bool活动{get；set；}
/// 
///与SalesDetails的一对多关系。
/// 
[OneToMany（级联操作=级联操作.All）]
公共列表SalesDetail{get；set；}
}

解决方案是在ProductListViewModel构造函数内初始化产品属性：

public class ProductListViewModel
{
   public ProductListViewModel ()
   {
      Product = new ProductViewModel();
   }
   .
   .
   .
}

感谢魏玛·亚米特·莫雷诺·佩雷斯的帮助，以及阿尔卡纳的干预。

解决方案是在ProductListViewModel构造函数中初始化产品属性：

public class ProductListViewModel { public ProductListViewModel () { Product = new ProductViewModel(); } . . . }

感谢魏玛·亚米特·莫雷诺·佩雷斯（Weimar Yamit Moreno Perez）的帮助，感谢阿尔卡纳（Archana）的干预。
您在哪里创建产品类对象？除非实例化，否则它将为null。双向绑定的作用是在视图和viewmodel中填充名称、成本等属性。但是我猜你的产品对象本身是空的，它将如何填充它的属性呢？谢谢@Archana，我编辑了我的问题来添加这个类，它在BusinessLayer名称空间中，当我获得产品时没有任何问题，但是当我尝试设置值时，它会让人沮丧。有什么想法吗？没有，我问过你在ProductListViewModel中的何处以及如何创建Product对象？@Archana你的意思是这行：public ProductViewModel Product{get；set；}？是的。这就是声明，对吗？您在哪里创建产品类对象？除非实例化，否则它将为null。双向绑定的作用是在视图和viewmodel中填充名称、成本等属性。但是我猜你的产品对象本身是空的，它将如何填充它的属性呢？谢谢@Archana，我编辑了我的问题来添加这个类，它在BusinessLayer名称空间中，当我获得产品时没有任何问题，但是当我尝试设置值时，它会让人沮丧。有什么想法吗？没有，我问过你在ProductListViewModel中在哪里以及如何创建Product对象？@Archana你是说这个吗