WindowsPhone7开发中使用SQLCE数据库实例
- 时间：2015年04月02日 15:26:43 来源：魔法猪系统重装大师官网 人气：16714
在WindowsPhone中有时候我们会一些数据的存储，这个时候我们有两种选择，一种是选择存在的独立存储文件中，一种是存储在数据库中。存储在独立存储文件中，这个相信很多用都会使用，这里不作为重点，本文主要讲一下在WindowsPhone中使用数据库SQL CE。
下面开始一步一步的带领大家实现在WindowsPhone 中使用SQL CE数据库。（该示例引自WindowsPhone 7应用开发）
一、首先，我们需要创建一个EmployeeTable类，映射为数据库中的Employee表
如下：
在创建之前需要添加引用：System.Data.Linq；
同时引入命名空间：using System.Data.Linq.Mapping;
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 | [Table]//特性标识该类为映射为数库中的表 //该类实现了INotifyPropertyChanged和INotifyPropertyChanging接口 public class EmployeeTable:INotifyPropertyChanged,INotifyPropertyChanging { private int _employeeId; //将EmployeeID映射为表的主键，特性Column里的含义分别为：主键，自增，int型不为空，不为空等 [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"); } } } private string _employeeName; [Column]//EmployeeName属性为表中EmployeeName字段 public string EmployeeName { get { return _employeeName; } set { if (_employeeName != value) { NotifyPropertyChanging("EmployeeName"); _employeeName = value; NotifyPropertyChanged("EmployeeName"); } } } private string _employeeDesc; [Column]//将EmployeeDesc属性映射为表中EmployeeDesc字段 public string EmployeeDesc { get { return _employeeDesc; } set { if (_employeeDesc != value) { NotifyPropertyChanging("EmployeeDesc"); _employeeDesc = value; NotifyPropertyChanged("EmployeeDesc"); } } } //定义PropertyChanged事件用来通知页面，表字段数据发生了改变 public event PropertyChangedEventHandler PropertyChanged; private void NotifyPropertyChanged(string propertyName) { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } //定义PropertyChanging事件通知数据上下文表的字段数据将要发生改变 public event PropertyChangingEventHandler PropertyChanging; private void NotifyPropertyChanging(string propertyname) { if (PropertyChanging != null) { PropertyChanging(this, new PropertyChangingEventArgs(propertyname)); } } } |
通过以上的这些操作，我们已经基本上完成了Employee表的创建，映射为数据库中的EmployeeTable表
二、下面我们来新建一个EmployeeDataContext.cs类文件，创建数据库的DataContent，该类继承自DataContent,在该类中定义连接字符串，如下：
首先需要引入命名空间：using system.data.Linq;
| public class EmployeeDataContext:DataContext { //数据库连接字符串 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) { } //定义员工信息表 public Table } |
三、创建EmployeeCollection类，该类的主要作用为页面数据绑定的集合。如下：
//绑定页面，进行显示用
| public class EmployeeCollection:INotifyPropertyChanged { //用于通知属性的改变 public event PropertyChangedEventHandler PropertyChanged; public void NotifyPropertyChanged(string propertyName) { if (PropertyChanged != null) { PropertyChanged(this,new PropertyChangedEventArgs (propertyName)); } } private ObservableCollection |
//创建EmployeeTables属性用来绑定页面数据
| public ObservableCollection { get { return _employeeTables; } set { if (_employeeTables != value) { _employeeTables = value; NotifyPropertyChanged("EmployeeTables"); } } } } |
四、这样一个完整的数据库就创建完毕了，那么我们该如何使用呢？一般的情况下我们都是在程序启动的时候加载数据库，为此我们可以在App.xaml文件的Launching事件中做如下处理：
| using (EmployeeDataContext db=new EmployeeDataContext(EmployeeDataContext.DBConnectionString)) { if (db.DatabaseExists() == false) { db.CreateDatabase(); } } |
五、下面做一个实例进行演示：
页面布局如下：
VerticalAlignment="Top" Width="160" Click="button2_Click" /> |
.cs页的处理代码如下：
| public partial class EmployeeShow : PhoneApplicationPage { //创建DataContext用于操作独立的数据库 private EmployeeDataContext employeeDB; private EmployeeCollection employeeCol = new EmployeeCollection(); |
| public EmployeeShow() { InitializeComponent(); //创建EmployeeDataContext实例 employeeDB = new EmployeeDataContext(EmployeeDataContext.DBConnectionString); var employeeInDB = from EmployeeTable employee in employeeDB.Employees select employee; //为页面创建数据绑定源 employeeCol.EmployeeTables = new System.Collections.ObjectModel.ObservableCollection listBox1.ItemsSource = employeeCol.EmployeeTables; } |
//删除信息
| private void deleteButton_Click(object sender, RoutedEventArgs e) { var button = sender as Button; if (button != null) { EmployeeTable edelete = button.DataContext as EmployeeTable; // employeeCol.EmployeeTables.Remove(edelete); employeeDB.Employees.DeleteOnSubmit(edelete); employeeDB.SubmitChanges(); } } |
//保存信息
| private void button2_Click(object sender, RoutedEventArgs e) { if (txtname.Text != "" && txtdesc.Text != "") { //编辑状态 if (State.Count > 0 && State["employee"] != null) { EmployeeTable employee = (EmployeeTable)State["employee"]; employee.EmployeeName = txtname.Text; employee.EmployeeDesc = txtdesc.Text; employeeDB.SubmitChanges(); employeeCol.EmployeeTables.Add(employee); State["employee"] = null; } Else//添加新的信息 { EmployeeTable newEmployee = new EmployeeTable { EmployeeName = txtname.Text, EmployeeDesc = txtdesc.Text }; employeeCol.EmployeeTables.Add(newEmployee); employeeDB.Employees.InsertOnSubmit(newEmployee); employeeDB.SubmitChanges(); txtname.Text = ""; txtdesc.Text = ""; } listBox1.ItemsSource = employeeCol.EmployeeTables; } else { MessageBox.Show("姓名和简介不能为空！"); } } |
//编辑信息
| private void editButton_Click(object sender, RoutedEventArgs e) { var button = sender as Button; if (button != null) { EmployeeTable eedit = button.DataContext as EmployeeTable; txtname.Text = eedit.EmployeeName; txtdesc.Text = eedit.EmployeeDesc; State["employee"] = eedit; employeeCol.EmployeeTables.Remove(eedit)； } } } |
效果如图：
好了，到这里我们已经基本上实现了在WindowsPhone手机中使用SQLCE数据库了，希望可以对朋友们有所帮助。
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