Windows Phone 7 本地数据库SQL Server CE（芒果更新）

时间：2011-06-08 来源：linzheng

在Windows Phone的第一个版本7.0版本里面是没有本地数据库支持的，要使用数据库只能够使用第三方的数据库组件。Windows Phone的本地数据库SQL Server CE是7.1版本即芒果更新的新特性，所以你要在应用程序中使用SQL Server CE数据库必须使用Windows Phone 7.1的API才行。下面用一个实例演示如何使用SQL Server CE数据库。（1）创建数据表以及数据库的数据上下文DateContent 先创建一个员工信息表，用于保存员工的名字和简介，员工表有一个自增的ID。 EmployeeTable.cs

using System.Data.Linq.Mapping;
using System.ComponentModel;

namespace SQLServerDemo
{
    [Table]
    public class EmployeeTable : INotifyPropertyChanged, INotifyPropertyChanging
    {
        // 定义员工表独立增长ID，设置为主键
        private int _employeeId;

        [Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "INT NOT NULL Identity", CanBeNull = false, AutoSync = AutoSync.OnInsert)]
        public int EmployeeID
        {
            get
            {
                return _employeeId;
            }
            set
            {
                if (_employeeId != value)
                {
                    NotifyPropertyChanging("EmployeeID");
                    _employeeId = value;
                    NotifyPropertyChanged("EmployeeID");
                }
            }
        }

        // 定义员工名字字段
        private string _employeeName;

        [Column]
        public string EmployeeName
        {
            get
            {
                return _employeeName;
            }
            set
            {
                if (_employeeName != value)
                {
                    NotifyPropertyChanging("EmployeeName");
                    _employeeName = value;
                    NotifyPropertyChanged("EmployeeName");
                }
            }
        }

        //定义员工简介字段
        private string _employeeDesc;

        [Column]
        public string EmployeeDesc
        {
            get
            {
                return _employeeDesc;
            }
            set
            {
                if (_employeeDesc != value)
                {
                    NotifyPropertyChanging("EmployeeDesc");
                    _employeeDesc = value;
                    NotifyPropertyChanged("EmployeeDesc");
                }
            }
        }

        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;

        //用来通知页面表的字段数据产生了改变
        private void NotifyPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }

        #endregion

        #region INotifyPropertyChanging Members

        public event PropertyChangingEventHandler PropertyChanging;

        // 用来通知数据上下文表的字段数据将要产生改变
        private void NotifyPropertyChanging(string propertyName)
        {
            if (PropertyChanging != null)
            {
                PropertyChanging(this, new PropertyChangingEventArgs(propertyName));
            }
        }

        #endregion

    }
}

创建数据库的DataContent，定义一个EmployeeDataContext类来继承DataContext，在EmployeeDataContext中定义数据库连接字符串，以及员工信息表。 EmployeeDataContext.cs

using System.Data.Linq;

namespace SQLServerDemo
{
    public class EmployeeDataContext : DataContext
    {
        // 数据库链接字符串
        public static string DBConnectionString = "Data Source=isostore:/Employee.sdf";

        // 传递数据库连接字符串到DataContext基类
        public EmployeeDataContext(string connectionString)
            : base(connectionString)
        { }

        // 定义一个员工信息表
        public Table<EmployeeTable> Employees;
    }
}

（2）创建页面数据绑定的集合 EmployeeCollection.cs

using System.ComponentModel;
using System.Collections.ObjectModel;

namespace SQLServerDemo
{
    //EmployeeCollection用于跟页面的数据绑定
    public class EmployeeCollection : INotifyPropertyChanged
    {
        //定义ObservableCollection来绑定页面的数据
        private ObservableCollection<EmployeeTable> _employeeTables;
        public ObservableCollection<EmployeeTable> EmployeeTables
        {
            get
            {
                return _employeeTables;
            }
            set
            {
                if (_employeeTables != value)
                {
                    _employeeTables = value;
                    NotifyPropertyChanged("EmployeeTables");
                }
            }
        }

        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;

        //用于通知属性的改变
        private void NotifyPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion
    }
}

（3）创建数据库，绑定数据，实现员工信息表的增删改查操作。在App.xaml.cs中的程序加载事件中进行创建数据库

private void Application_Launching(object sender, LaunchingEventArgs e)
        {
            //如果数据库不存在则创建一个数据库
            using (EmployeeDataContext db = new EmployeeDataContext(EmployeeDataContext.DBConnectionString))
            {
                if (db.DatabaseExists() == false)
                {
                    //创建一个数据库
                    db.CreateDatabase();
                }
            }
        }

MainPage.xaml文件代码

<phone:PhoneApplicationPage 
    x:Class="SQLServerDemo.MainPage"
    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"
    mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="768"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    shell:SystemTray.IsVisible="True">

    <Grid x:Name="LayoutRoot" Background="Transparent">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
            <TextBlock x:Name="ApplicationTitle" Text="MY APPLICATION" Style="{StaticResource PhoneTextNormalStyle}"/>
            <TextBlock x:Name="PageTitle" Text="SQL Server" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
        </StackPanel>

        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
            <Grid Margin="0,0,0,385">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*" />
                    <ColumnDefinition Width="Auto" />
                </Grid.ColumnDefinitions>
                <TextBlock FontSize="30" Height="37" HorizontalAlignment="Left" Margin="12,18,0,0" Name="textBlock1" Text="员工名字:" VerticalAlignment="Top" />
                <TextBox Name="name" Text=""  Margin="145,0,6,144" />
                
                <TextBlock FontSize="30" Height="52" HorizontalAlignment="Left" Margin="18,74,0,0" Name="textBlock2" Text="简介：" VerticalAlignment="Top" />
                <TextBox Height="79" HorizontalAlignment="Left" Margin="93,65,0,0" Name="desc" Text="" VerticalAlignment="Top" Width="357" />

                <Button 
                    Content="保存" x:Name="addButton"
                    Click="addButton_Click" Margin="219,132,6,6" />

            </Grid>

            <ListBox x:Name="toDoItemsListBox" ItemsSource="{Binding EmployeeTables}" Margin="12,241,12,0" Width="440">
               <ListBox.ItemTemplate>
                    <DataTemplate>
                        <Grid HorizontalAlignment="Stretch" Width="440">
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="50" />
                                <ColumnDefinition Width="*" />
                                <ColumnDefinition Width="100" />
                            </Grid.ColumnDefinitions>
                        
                            <TextBlock
                                Text="{Binding EmployeeName}"
                                FontSize="{StaticResource PhoneFontSizeLarge}"
                                Grid.Column="1"
                                VerticalAlignment="Center"/>
                            <Button
                                Grid.Column="2"
                                x:Name="deleteButton"
                                BorderThickness="0"                                
                                Margin="0"
                                Click="deleteButton_Click"
                                Content="删除">
                            </Button>
                            <Button
                                Grid.Column="1"
                                x:Name="editButton"
                                BorderThickness="0"                                
                                Margin="209,0,81,0"
                                Click="editButton_Click"
                                Content="编辑" Grid.ColumnSpan="2">
                            </Button>
                        </Grid>
                   </DataTemplate>
                </ListBox.ItemTemplate> 
            </ListBox>   
        </Grid>
    </Grid>

</phone:PhoneApplicationPage>

MainPage.xaml.cs文件代码

using System.Linq;
using System.Windows;
using System.Windows.Controls;
using Microsoft.Phone.Controls;
using System.Collections.ObjectModel;

namespace SQLServerDemo
{
    public partial class MainPage : PhoneApplicationPage
    {
        // 创建DataContext实例用于用于操作本地的数据库
        private EmployeeDataContext employeeDB;
        private EmployeeCollection employeeCol = new EmployeeCollection();

        public MainPage()
        {
            InitializeComponent();

            //连接数据库并初始化DataContext实例
            employeeDB = new EmployeeDataContext(EmployeeDataContext.DBConnectionString);

            // 使用Linq查询语句查询EmployeeTable表的所有数据
            var employeesInDB = from EmployeeTable employee in employeeDB.Employees
                                select employee;

            // 将查询的结果返回到页面数据绑定的集合里面
            employeeCol.EmployeeTables = new ObservableCollection<EmployeeTable>(employeesInDB);

            //赋值给当前页面的DataContext用于数据绑定
            this.DataContext = employeeCol;
        }

        /// <summary>
        /// 删除操作
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void deleteButton_Click(object sender, RoutedEventArgs e)
        {
            // 获取单击的按钮实例
            var button = sender as Button;

            if (button != null)
            {
                //获取当前按钮绑定的DataContext，即当前的删除的EmployeeTable实例
                EmployeeTable employeeForDelete = button.DataContext as EmployeeTable;
                //移除绑定集合里面要删除的EmployeeTable记录
                employeeCol.EmployeeTables.Remove(employeeForDelete);
                // 移除数据库里面要删除的EmployeeTable记录
                employeeDB.Employees.DeleteOnSubmit(employeeForDelete);
                //保存数据库的改变
                employeeDB.SubmitChanges();
            }
        }

        /// <summary>
        /// 保存操作，处理新增和编辑员工信息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void addButton_Click(object sender, RoutedEventArgs e)
        {
            //控制员工名字和简介不能为空
            if (name.Text != "" && desc.Text != "")
            {
                if (State.Count>0 && State["employee"] != null )//编辑状态
                {
                    //获取编辑的EmployeeTable对象
                    EmployeeTable employee = (EmployeeTable)State["employee"];
                    employee.EmployeeName = name.Text;
                    employee.EmployeeDesc = desc.Text;
                    //保存数据库的改变
                    employeeDB.SubmitChanges();
                    //添加绑定集合的数据,因为在单击编辑的时候移除了
                    employeeCol.EmployeeTables.Add(employee);
                    State["employee"] = null;
                }
                else//新增状态
                {
                    //创建一条表的数据
                    EmployeeTable newEmployee = new EmployeeTable { EmployeeName = name.Text, EmployeeDesc = desc.Text };
                    //添加绑定集合的数据
                    employeeCol.EmployeeTables.Add(newEmployee);
                    //插入数据库
                    employeeDB.Employees.InsertOnSubmit(newEmployee);
                    //保存数据库的改变
                    employeeDB.SubmitChanges();
                }
                
                name.Text = "";
                desc.Text = "";
            }
            else
            {
                MessageBox.Show("姓名和简介不能为空！");
            }
        }

        /// <summary>
        /// 编辑操作
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void editButton_Click(object sender, RoutedEventArgs e)
        {
            // 获取单击的按钮实例
            var button = sender as Button;

            if (button != null)
            {
                //获取当前按钮绑定的DataContext，即当前的编辑的EmployeeTable实例
                EmployeeTable employeeForEdit = button.DataContext as EmployeeTable;
                name.Text = employeeForEdit.EmployeeName;
                desc.Text = employeeForEdit.EmployeeDesc;
                //将需要编辑的表实例存储在State里面
                State["employee"] = employeeForEdit;
                employeeCol.EmployeeTables.Remove(employeeForEdit);
            }
        }
    }
}

运行效果如下：