• 与众不同 windows phone (7) Local Database(本地数据库)


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    与众不同 windows phone (7) - Local Database(本地数据库)



    作者:webabcd


    介绍
    与众不同 windows phone 7.5 (sdk 7.1) 之本地数据库

    • 概述
    • 演示如何使用“本地数据库



    示例
    1、概述
    Summary.xaml

    <phone:PhoneApplicationPage 
        x:Class="Demo.LocalDatabase.Summary"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
        xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        FontFamily="{StaticResource PhoneFontFamilyNormal}"
        FontSize="{StaticResource PhoneFontSizeNormal}"
        Foreground="{StaticResource PhoneForegroundBrush}"
        SupportedOrientations="Portrait" Orientation="Portrait"
        mc:Ignorable="d" d:DesignHeight="768" d:DesignWidth="480"
        shell:SystemTray.IsVisible="True">
    
        <Grid x:Name="LayoutRoot" Background="Transparent">
            <TextBlock TextWrapping="Wrap">
                <Run>本地数据库概述</Run>
                <LineBreak />
                <LineBreak />
                <Run>1、App 创建数据库时,其文件会被保存到独立存储;程序包内数据库只能被读取,如果需要更新它,则必须把其复制到独立存储后再操作</Run>
                <LineBreak />
                <Run>2、数据库结构发生改变时优先使用 DatabaseSchemaUpdater 来更新数据库结构;数据迁移是下策</Run>
                <LineBreak />
                <Run>3、只读场景下建议将 DataContext 的 ObjectTrackingEnabled 设置为 false(因为只读时不需要对象跟踪),从而关闭对象跟踪以减小内存使用量</Run>
                <LineBreak />
                <Run>4、在多线程操作本地数据库的场景下,建议使用互斥锁,即 System.Threading.Mutex</Run>
            </TextBlock>
        </Grid>
        
    </phone:PhoneApplicationPage>



    2、使用“本地数据库”的 Demo
    Model层 - ModelBase.cs

    using System;
    using System.Net;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Documents;
    using System.Windows.Ink;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Animation;
    using System.Windows.Shapes;
    
    using System.ComponentModel;
    using System.Data.Linq.Mapping;
    using System.Data.Linq;
    
    namespace Demo.LocalDatabase.Model
    {
        public class ModelBase : INotifyPropertyChanged, INotifyPropertyChanging
        {
            // 实现 INotifyPropertyChanged 是为了属性变更后的通知
            public event PropertyChangedEventHandler PropertyChanged;
            protected void NotifyPropertyChanged(string propertyName)
            {
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
                }
            }
    
    
            // 实现 INotifyPropertyChanging 是为了最大限度地减少内存使用量(NotifyPropertyChanging 的用法:在属性赋值之前调用,具体可见 Category 或 Product)
            /*
             * 为什么会减少内存使用量呢?
             * 因为 LINQ to SQL 更改跟踪是通过维护每个对象的两个副本进行工作的,第一个副本保存原始数据,第二个副本有程序更改,这样提交更新时 LINQ to SQL 就知道哪些数据被更改了,从而只提交这些被更改的数据
             * INotifyPropertyChanging 接口允许应用程序在将修改后的数据提交到数据库前通知 DataContext,DataContext 可以将该通知用作创建副本的触发器,这样就不用保留第二个副本了,从而减少内存使用
             */
            public event PropertyChangingEventHandler PropertyChanging;
            protected void NotifyPropertyChanging(string propertyName)
            {
                if (PropertyChanging != null)
                {
                    PropertyChanging(this, new PropertyChangingEventArgs(propertyName));
                }
            }
        }
    }

    Model层 - Category.cs

    using System;
    using System.Net;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Documents;
    using System.Windows.Ink;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Animation;
    using System.Windows.Shapes;
    
    using System.Data.Linq.Mapping;
    using System.Data.Linq;
    
    namespace Demo.LocalDatabase.Model
    {
        /*
         * Table - 将类标记为数据库中的一个表
         * Index - 把类中的指定字段标记为索引字段
         */
        [Table]
        public class Category : ModelBase
        {
            // 版本列,可以显著改进表的更新性能
            [Column(IsVersion = true)]
            private Binary _version;
    
    
            private int _categoryId;
            /*
             * Column - 将属性标记为数据表中的一个字段
             *     IsPrimaryKey - 是否是主键
             *     IsDbGenerated - 数据是否由数据库自动生成,如自增列
             *     DbType = "INT NOT NULL Identity" - int类型,不能为null,标识列
             *     CanBeNull - 是否可以为 null
             *     AutoSync = AutoSync.OnInsert - 标记此值的作用是:当数据添加完成后,此属性的值会自动同步为数据库自增后的值
             */
            [Column(DbType = "INT NOT NULL IDENTITY", IsDbGenerated = true, IsPrimaryKey = true)]
            public int CategoryId
            {
                get { return _categoryId; }
                set
                {
                    NotifyPropertyChanging("CategoryId");
                    _categoryId = value;
                    NotifyPropertyChanged("CategoryId");
                }
            }
    
            private string _name;
            [Column]
            public string Name
            {
                get { return _name; }
                set
                {
                    NotifyPropertyChanging("Name");
                    _name = value;
                    NotifyPropertyChanged("Name");
                }
            }
    
    
            private EntitySet<Product> _products;
            /*
             * Association - 用于标记表之间的关联关系
             *     Storage - 指定用于保存关联数据的私有字段。本例中类型为 EntitySet<T> 的私有字段 _products 用于保存关联数据,本例中所谓的关联数据就是 Category 下的 Products
             *     ThisKey - 关联数据在本表中所对应的 key 字段
             *     OtherKey - 关联数据在他表中所对应的 key 字段
             *     IsForeignKey - 是否是外键
             */
            [Association(Storage = "_products", ThisKey = "CategoryId", OtherKey = "_categoryId")]
            public EntitySet<Product> Products
            {
                get { return this._products; }
                set 
                {
                    /*
                     * Assign() - 将一个 EntitySet<T> 赋值给另一个 EntitySet<T> 
                     */
                    // 将 value 赋值给 _products
                    this._products.Assign(value); 
                }
            }
    
    
            // 指定 _products 做添加和删除操作时的关联操作
            public Category()
            {
                _products = new EntitySet<Product>
                (
                    new Action<Product>(this.attach),
                    new Action<Product>(this.detach)
                );
            }
    
            // _products 添加 Product 时的关联操作
            private void attach(Product product)
            {
                NotifyPropertyChanging("Product");
                product.Category = this;
            }
    
            // _products 删除 Product 时的关联操作
            private void detach(Product product)
            {
                NotifyPropertyChanging("Product");
                product.Category = null;
            }
    
        }
    }

    Model层 - Product.cs

    using System;
    using System.Net;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Documents;
    using System.Windows.Ink;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Animation;
    using System.Windows.Shapes;
    
    using System.Data.Linq.Mapping;
    using System.Data.Linq;
    using Microsoft.Phone.Data.Linq.Mapping;
    
    namespace Demo.LocalDatabase.Model
    {
        /*
         * Table - 将类标记为数据库中的一个表
         * Index - 把类中的指定字段标记为索引字段
         */
        [Table]
        [Index(Columns = "Name ASC, ProductId DESC", Name="MyIndex")]
        public class Product : ModelBase
        {
            // 版本列,可以显著改进表的更新性能
            [Column(IsVersion = true)]
            private Binary _version;
    
    
            private int _productId;
            /*
             * Column - 将属性标记为数据表中的一个字段
             *     IsPrimaryKey - 是否是主键
             *     IsDbGenerated - 数据是否由数据库自动生成,如自增列
             *     DbType = "INT NOT NULL Identity" - int类型,不能为null,标识列
             *     CanBeNull - 是否可以为 null
             *     AutoSync = AutoSync.OnInsert - 标记此值的作用是:当数据添加完成后,此属性的值会自动同步为数据库自增后的值
             */
            [Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "INT NOT NULL Identity", CanBeNull = false, AutoSync = AutoSync.OnInsert)]
            public int ProductId
            {
                get { return _productId; }
                set
                {
                    if (_productId != value)
                    {
                        NotifyPropertyChanging("ProductId");
                        _productId = value;
                        NotifyPropertyChanged("ProductId");
                    }
                }
            }
    
            private string _name;
            [Column]
            public string Name
            {
                get { return _name; }
                set
                {
                    if (_name != value)
                    {
                        NotifyPropertyChanging("Name");
                        _name = value;
                        NotifyPropertyChanged("Name");
                    }
                }
            }
    
            private double _price;
            [Column]
            public double Price
            {
                get { return _price; }
                set
                {
                    if (_price != value)
                    {
                        NotifyPropertyChanging("Price");
                        _price = value;
                        NotifyPropertyChanged("Price");
                    }
                }
            }
    
    
            [Column]
            internal int _categoryId;
    
            private EntityRef<Category> _category;
            /*
             * Association - 用于标记表之间的关联关系
             *     Storage - 指定用于保存关联数据的私有字段。本例中类型为 EntityRef<T> 的私有字段 _category 用于保存关联数据,本例中所谓的关联数据就是 Product 所属的 Category
             *     ThisKey - 关联数据在本表中所对应的 key 字段
             *     OtherKey - 关联数据在他表中所对应的 key 字段
             *     IsForeignKey - 是否是外键
             */
            [Association(Storage = "_category", ThisKey = "_categoryId", OtherKey = "CategoryId", IsForeignKey = true)]
            public Category Category
            {
                get { return _category.Entity; }
                set
                {
                    NotifyPropertyChanging("Category");
    
                    // 更新 Storage 以及 ThisKey
                    _category.Entity = value;
                    if (value != null)
                        _categoryId = value.CategoryId;
    
                    NotifyPropertyChanging("Category");
                }
            }
        }
    }

    Model层 - MyContext.cs

    using System;
    using System.Net;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Documents;
    using System.Windows.Ink;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Animation;
    using System.Windows.Shapes;
    
    using System.Data.Linq;
    
    namespace Demo.LocalDatabase.Model
    {
        public class MyContext : DataContext
        {
            public MyContext(string connectionString)
                : base(connectionString)
            { }
    
            public Table<Product> Products;
    
            public Table<Category> Categories;
        }
    }


    ViewModel层 - MyViewModel.cs

    /*
     * 连接字符串设置
     *     1、data source - 本地数据库文件地址
     *          示例:data source=isostore:/database.sdf;appdata:/ 代表程序包内,isostore:/ 代表独立存储,默认为独立存储
     *     2、pwd - 密码
     *     3、max buffer size - 最大内存使用量(保存到磁盘之前会使用内存),默认值为 384,最大值为 5120,单位为 KB
     *     4、max database size - 数据库文件的最大大小,默认值为 32,最大值为 512,单位为 MB
     *     5、file mode - 操作数据库文件时的模式
     *          Read Write - 可读写,默认值
     *          Read Only - 只读
     *          Exclusive - 不允许其他进程打开或修改数据库
     *          Shared Read - 数据库打开后,允许其他进程读取,但不允许其他进程修改
     *     6、Culture Identifier - 区域代码,如中国大陆地区是 zh-CN(创建数据库时此属性才有用)
     *     7、Case Sensitive - 排序时是否区分大小写,默认值为 false(创建数据库时此属性才有用)
     */
    
    using System;
    using System.Net;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Documents;
    using System.Windows.Ink;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Animation;
    using System.Windows.Shapes;
    
    using System.ComponentModel;
    using Demo.LocalDatabase.Model;
    using Microsoft.Phone.Data.Linq;
    using System.Collections.ObjectModel;
    
    using System.Linq;
    using System.Data.Linq;
    
    namespace Demo.LocalDatabase.ViewModel
    {
        public class MyViewModel : INotifyPropertyChanged
        {
            private MyContext _context;
    
            public MyViewModel()
            {
                DataLoadOptions dlo = new DataLoadOptions();
                dlo.LoadWith<Category>(p => p.Products);
                dlo.AssociateWith<Category>(p => p.Products.OrderByDescending(x => x.Price));
    
                _context = new MyContext("Data Source=isostore:/database.sdf");
                _context.LoadOptions = dlo;
    
                Init();
    
                Categories = new ObservableCollection<Category>(_context.Categories.ToList());
            }
    
            public void AddProduct(Product product)
            {
                var category = Categories.Single(p => p.CategoryId == product.Category.CategoryId);
                category.Products.Add(product);
    
                _context.Products.InsertOnSubmit(product);
                _context.SubmitChanges();
            }
    
            public void DeleteProduct(Product product)
            {
                var category = Categories.Single(p => p.CategoryId == product.Category.CategoryId);
                category.Products.Remove(product);
    
                _context.Products.DeleteOnSubmit(product);
                _context.SubmitChanges();
            }
    
            public void Init()
            {
                if (!_context.DatabaseExists())
                {
                    _context.CreateDatabase();
    
                    DatabaseSchemaUpdater dbUpdater = _context.CreateDatabaseSchemaUpdater();
                    dbUpdater.DatabaseSchemaVersion = 0;
                    dbUpdater.Execute();
    
                    Category c1 = new Category { Name = "" };
                    c1.Products.Add(new Product { Name = "牛肉", Price = 35.5 });
                    c1.Products.Add(new Product { Name = "羊肉", Price = 38 });
                    Category c2 = new Category { Name = "水果" };
                    c2.Products.Add(new Product { Name = "苹果", Price = 2.5 });
                    c2.Products.Add(new Product { Name = "香蕉", Price = 3.2 });
                    Category c3 = new Category { Name = "蔬菜" };
                    c3.Products.Add(new Product { Name = "菠菜", Price = 2.2 });
                    c3.Products.Add(new Product { Name = "白菜", Price = 1.3 });
    
                    _context.Categories.InsertOnSubmit(c1);
                    _context.Categories.InsertOnSubmit(c2);
                    _context.Categories.InsertOnSubmit(c3);
    
                    _context.SubmitChanges();
                }
                else
                {
                    /*
                     * DatabaseSchemaUpdater - 数据库结构更新器
                     *     DatabaseSchemaVersion - 数据库结构的版本
                     *     Execute() - 更新数据库结构和版本号
                     *     
                     * 数据库结构有改变时,用以下方法更新不同版本的数据库结构
                     *     AddColumn<T>(string columnPropertyName) - 为表 T 添加列 columnPropertyName
                     *     AddIndex<T>(string indexName) - 为表 T 添加索引 indexName
                     *     AddTable<T>() - 为数据库添加表 T
                     *     AddAssociation<T>(string associationPropertyName) - 为表 T 添加数据库关联 associationPropertyName
                     */
    
                    DatabaseSchemaUpdater dbUpdater = _context.CreateDatabaseSchemaUpdater();
    
                    if (dbUpdater.DatabaseSchemaVersion == 10)
                    {
                        dbUpdater.AddColumn<Product>("UpdateTime");
                     
                        dbUpdater.DatabaseSchemaVersion = 11;
                        dbUpdater.Execute();
                    }
                }
            }
    
            private ObservableCollection<Category> _categories;
            public ObservableCollection<Category> Categories
            {
                get { return _categories; }
                set
                {
                    _categories = value;
                    NotifyPropertyChanged("Categories");
                }
            }
    
    
            public event PropertyChangedEventHandler PropertyChanged;
            private void NotifyPropertyChanged(string propertyName)
            {
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
                }
            }
        }
    }


    View层 - App.xaml

    <Application 
        x:Class="Demo.App"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"       
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
        xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
        
        xmlns:localDatabaseViewModel="clr-namespace:Demo.LocalDatabase.ViewModel">
    
        <Application.Resources>
    
            <localDatabaseViewModel:MyViewModel x:Key="LocalDatabaseViewModel" />
            
        </Application.Resources>
    
    </Application>

    View层 - NewProduct.xaml

    <phone:PhoneApplicationPage 
        x:Class="Demo.LocalDatabase.NewProduct"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
        xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        FontFamily="{StaticResource PhoneFontFamilyNormal}"
        FontSize="{StaticResource PhoneFontSizeNormal}"
        Foreground="{StaticResource PhoneForegroundBrush}"
        SupportedOrientations="Portrait" Orientation="Portrait"
        mc:Ignorable="d" d:DesignHeight="696" d:DesignWidth="480"
        shell:SystemTray.IsVisible="True"
        
        xmlns:toolkit="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Toolkit"
        DataContext="{Binding Source={StaticResource LocalDatabaseViewModel}}">
        
        <Grid x:Name="LayoutRoot" Background="Transparent">
            <StackPanel Orientation="Vertical">
                <TextBlock Text="Product Name"/>
                <TextBox x:Name="txtProductName"/>
                
                <TextBlock Text="Product Price"/>
                <TextBox x:Name="txtProductPrice"/>
    
                <TextBlock Text="Product Category"/>
                <toolkit:ListPicker x:Name="listPickerCategory" ItemsSource="{Binding Categories}" DisplayMemberPath="Name" />
            </StackPanel>
        </Grid>
    
        <phone:PhoneApplicationPage.ApplicationBar>
            <shell:ApplicationBar Mode="Default" IsVisible="True">
                <shell:ApplicationBarIconButton x:Name="btnConfirm" IconUri="/ApplicationBarDemo/Assets/appbar.check.rest.png" Text="确认" Click="btnConfirm_Click" />
                <shell:ApplicationBarIconButton x:Name="btnCancel" IconUri="/ApplicationBarDemo/Assets/appbar.cancel.rest.png" Text="取消" Click="btnCancel_Click" />
            </shell:ApplicationBar>
        </phone:PhoneApplicationPage.ApplicationBar>
    
    </phone:PhoneApplicationPage>

    View层 - NewProduct.xaml.cs

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Net;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Documents;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Animation;
    using System.Windows.Shapes;
    using Microsoft.Phone.Controls;
    
    using Demo.LocalDatabase.ViewModel;
    using Demo.LocalDatabase.Model;
    
    namespace Demo.LocalDatabase
    {
        public partial class NewProduct : PhoneApplicationPage
        {
            public NewProduct()
            {
                InitializeComponent();
            }
    
            private void btnConfirm_Click(object sender, EventArgs e)
            {
                double price = 0;
                if (!double.TryParse(txtProductPrice.Text, out price))
                {
                    MessageBox.Show("价格必须是 double 型");
                    return;
                }
    
                var vm = Application.Current.Resources["LocalDatabaseViewModel"] as MyViewModel;
    
                Product product = new Product()
                {
                    Name = txtProductName.Text,
                    Price = double.Parse(txtProductPrice.Text),
                    Category = (Category)listPickerCategory.SelectedItem
                };
    
                vm.AddProduct(product);
    
                NavigationService.Navigate(new Uri("/LocalDatabase/Demo.xaml", UriKind.Relative));
            }
    
            private void btnCancel_Click(object sender, EventArgs e)
            {
    
            }
        }
    }

    View层 - Demo.xaml

    <phone:PhoneApplicationPage 
        x:Class="Demo.LocalDatabase.Demo"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
        xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        FontFamily="{StaticResource PhoneFontFamilyNormal}"
        FontSize="{StaticResource PhoneFontSizeNormal}"
        Foreground="{StaticResource PhoneForegroundBrush}"
        SupportedOrientations="Portrait" Orientation="Portrait"
        mc:Ignorable="d" d:DesignHeight="696" d:DesignWidth="480"
        shell:SystemTray.IsVisible="True"
        
        DataContext="{Binding Source={StaticResource LocalDatabaseViewModel}}"
        xmlns:controls="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls">
    
        <phone:PhoneApplicationPage.Resources>
            <DataTemplate x:Key="item">
                <ListBox ItemsSource="{Binding Products}">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <Grid Width="460" HorizontalAlignment="Center">
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="5*" />
                                    <ColumnDefinition Width="5*" />
                                </Grid.ColumnDefinitions>
    
                                <StackPanel Orientation="Horizontal" VerticalAlignment="Center">
                                    <TextBlock Text="{Binding Name}" />
                                    <TextBlock Text="{Binding Price}" Margin="10 0 0 0" />
                                </StackPanel>
    
                                <StackPanel Orientation="Horizontal" Grid.Column="1" HorizontalAlignment="Right">
                                    <Button x:Name="btnDelete" Content="删除" Click="btnDelete_Click" />
                                </StackPanel>
                            </Grid>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
            </DataTemplate>
            <DataTemplate x:Key="header">
                <TextBlock Text="{Binding Name}" />
            </DataTemplate>
        </phone:PhoneApplicationPage.Resources>
    
        <Grid x:Name="LayoutRoot" Background="Transparent">
            <controls:Pivot x:Name="pivot"
                Title="产品列表" 
                ItemTemplate="{StaticResource item}" 
                HeaderTemplate="{StaticResource header}"
                ItemsSource="{Binding Categories}">
            </controls:Pivot>
        </Grid>
    
        <phone:PhoneApplicationPage.ApplicationBar>
            <shell:ApplicationBar Mode="Default" IsVisible="True">
                <shell:ApplicationBarIconButton x:Name="btnAddProduct" IconUri="/ApplicationBarDemo/Assets/appbar.add.rest.png" Text="添加产品" Click="btnAddProduct_Click" />
            </shell:ApplicationBar>
        </phone:PhoneApplicationPage.ApplicationBar>
    </phone:PhoneApplicationPage>

    View层 - Demo.xaml.cs

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Net;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Documents;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Animation;
    using System.Windows.Shapes;
    using Microsoft.Phone.Controls;
    using Demo.LocalDatabase.ViewModel;
    using Demo.LocalDatabase.Model;
    
    namespace Demo.LocalDatabase
    {
        public partial class Demo : PhoneApplicationPage
        {
            public Demo()
            {
                InitializeComponent();
            }
    
            private void btnAddProduct_Click(object sender, EventArgs e)
            {
                NavigationService.Navigate(new Uri("/LocalDatabase/NewProduct.xaml", UriKind.Relative));
            }
    
            private void btnDelete_Click(object sender, RoutedEventArgs e)
            {
                var vm = Application.Current.Resources["LocalDatabaseViewModel"] as MyViewModel;
                vm.DeleteProduct((sender as Button).DataContext as Product);
            }
        }
    }



    OK
    [源码下载]

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  • 原文地址:https://www.cnblogs.com/webabcd/p/2560696.html
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