背水一战 Windows 10 之 MVVM（Model-View-ViewModel）

• 通过 x:Bind 实现 MVVM（不用 Command）

示例

1、Model

MVVM/Model/Product.cs

/* * Model 层的实体类，如果需要通知则需要实现 INotifyPropertyChanged 接口 */using System.ComponentModel;namespace Windows10.MVVM.Model{    public class Product : INotifyPropertyChanged    {        public Product()        {            ProductId = 0;            Name = "";            Category = "";        }        private int _productId;        public int ProductId        {            get { return _productId; }            set            {                _productId = value;                RaisePropertyChanged(nameof(ProductId));            }        }        private string _name;        public string Name        {            get { return _name; }            set            {                _name = value;                RaisePropertyChanged(nameof(Name));            }        }        private string _category;        public string Category        {            get { return _category; }            set            {                _category = value;                RaisePropertyChanged(nameof(Category));            }        }                public event PropertyChangedEventHandler PropertyChanged;        protected void RaisePropertyChanged(string name)        {            if (PropertyChanged != null)            {                PropertyChanged(this, new PropertyChangedEventArgs(name));            }        }    }}

MVVM/Model/ProductDatabase.cs

/* * Model 层的数据持久化操作（本地或远程） *  * 本例只是一个演示 */using System;using System.Collections.Generic;using System.Linq;namespace Windows10.MVVM.Model{    public class ProductDatabase    {        private List
     
       _products = null;        public List
      
        GetProducts()        {            if (_products == null)            {                Random random = new Random();                _products = new List
       
        ();                for (int i = 0; i < 100; i++)                {                    _products.Add                    (                        new Product                        {                            ProductId = i,                            Name = "Name" + i.ToString().PadLeft(4, '0'),                            Category = "Category" + (char)random.Next(65, 91)                        }                    );                }            }            return _products;        }        public List
        
          GetProducts(string name, string category)        {            return GetProducts().Where(p => p.Name.Contains(name) && p.Category.Contains(category)).ToList();        }        public void Update(Product product)        {            var oldProduct = _products.Single(p => p.ProductId == product.ProductId);            oldProduct = product;        }        public Product Add(string name, string category)        {            Product product = new Product();            product.ProductId = _products.Max(p => p.ProductId) + 1;            product.Name = name;            product.Category = category;            _products.Insert(0, product);            return product;        }        public void Delete(Product product)        {            _products.Remove(product);        }    }}
        
       
      
     

2、ViewModel

MVVM/ViewModel2/ProductViewModel.cs

/* * ViewModel 层 */using System.Collections.ObjectModel;using System.ComponentModel;using Windows.UI.Xaml;using Windows10.MVVM.Model;namespace Windows10.MVVM.ViewModel2{    public class ProductViewModel : INotifyPropertyChanged    {        // 用于提供 Products 数据        private ObservableCollection
     
       _products;        public ObservableCollection
      
        Products        {            get { return _products; }            set            {                _products = value;                RaisePropertyChanged(nameof(Products));            }        }        // 用于“添加”和“查询”的 Product 对象        private Product _product;        public Product Product        {            get { return _product; }            set            {                _product = value;                RaisePropertyChanged(nameof(Product));            }        }        // 数据库对象        private ProductDatabase _context = null;        public ProductViewModel()        {            _context = new ProductDatabase();            Product = new Product();            Products = new ObservableCollection
       
        (_context.GetProducts());        }        public void GetProducts(object sender, RoutedEventArgs e)        {            // 从 Model 层获取数据            Products = new ObservableCollection
        
         (_context.GetProducts(Product.Name, Product.Category));        }        public void AddProduct(object sender, RoutedEventArgs e)        {            // 在 Model 层添加一条数据            Product newProduct = _context.Add(Product.Name, Product.Category);            // 更新 ViewModel 层数据            Products.Insert(0, newProduct);        }        public void UpdateProduct(object sender, RoutedEventArgs e)        {            Product product = ((FrameworkElement)sender).Tag as Product;            // 更新 ViewModel 层数据            product.Name = product.Name + "U";            product.Category = product.Category + "U";            // 更新 Model 层数据            _context.Update(product);        }        public void DeleteProduct(object sender, RoutedEventArgs e)        {            Product product = ((FrameworkElement)sender).Tag as Product;            // 更新 Model 层数据            _context.Delete(product);            // 更新 ViewModel 层数据            Products.Remove(product);        }        public event PropertyChangedEventHandler PropertyChanged;        protected void RaisePropertyChanged(string name)        {            if (PropertyChanged != null)            {                PropertyChanged(this, new PropertyChangedEventArgs(name));            }        }    }}
        
       
      
     

3、View

MVVM/View/Demo2.xaml