Silverlight实用窍门系列：30.Silverlight中创建一个最简单的WCF RIA Services访问数据库实例【实例源码+数据库下载】

本文将建立一个最简单的WCF RIA Services访问数据库的实例,附带有数据库文件，可以在Sql Server中附加数据库，在本文中并没有采用ADO.NET实体数据模型绑定数据库，而是单独写一个类来连接数据库查询数据表并返回值，下面我们看详细步骤。

第一步：首先我们打开VS2010，新建一个Silverlight应用程序项目SLGetDataFromWCFRIA。DB.cs数据库访问类

/// <summary>
/// DB 的摘要说明
/// </summary>
public   class  DB
{
private static IsolationLevel m_isoLevel = IsolationLevel.ReadUncommitted;
private static string connStr = string.Empty;

private DB()
{
}

#region DB2 Access Functions

static public IsolationLevel IsolationLevel
{
get
{
return m_isoLevel;
}
}

/// <summary>
/// Gets Connection out of Web.config
/// </summary>
/// <returns>Returns SqlConnection</returns>
public static SqlConnection GetConnection()
{
if (connStr == string.Empty)
{
AppSettingsReader configurationAppSettings = new AppSettingsReader();
connStr = "Data Source=CXL-DC6F5F6CA80;POOLING=FALSE;database=SLRiaTest;User ID=sa;Password=123456";
}

SqlConnection conn = new SqlConnection(connStr);
conn.Open();
return conn;
}

/// <summary>
/// Gets data out of database using a plain text string command
/// </summary>
/// <param name="sql">string command to be executed</param>
/// <returns>DataTable with results</returns>
static public DataSet Getdata(string sql)
{
using (SqlConnection conn = GetConnection())
{
using (SqlTransaction trans = conn.BeginTransaction(m_isoLevel))
{
try
{
using (SqlCommand cmd = conn.CreateCommand())
{
if (sql != null)
{
sql = sql.ToLower().Replace("<;", "");//.Replace(Convert.ToChar(32).ToString(), " ").Replace(" ", " ").Replace("%32", " ").Replace("%20", " ");
sql = sql.Replace(">;", "");
sql = sql.Replace("script", "");
sql = sql.Replace("object", "");
sql = sql.Replace("applet", "");
sql = sql.Replace("[", "");
sql = sql.Replace("]", "");
sql = sql.Replace("execute", "");
sql = sql.Replace("exec", "");
sql = sql.Replace("union", "");
sql = sql.Replace("drop", "");
sql = sql.Replace("delete", "");
//  sql = sql.Replace("chr", "");
//sql = sql.Replace("mid", "");
sql = sql.Replace("truncate", "");
sql = sql.Replace("nchar", "");
//  sql = sql.Replace("varchar", "");
//sql = sql.Replace("char", "");
sql = sql.Replace("alter", "");
// sql = sql.Replace("cast", "");
sql = sql.Replace("exists", "");
sql = sql.Replace("update", "");
}
cmd.Transaction = trans;
cmd.CommandType = CommandType.Text;
cmd.CommandText = sql;
using (DataSet ds = new DataSet())
{
using (SqlDataAdapter da = new SqlDataAdapter())
{
da.SelectCommand = cmd;
da.SelectCommand.Connection = conn;
da.Fill(ds);
return ds;
}
}
}
}
finally
{
trans.Commit();
}
}
}
}

#endregion

}

第九步：鼠标右键点击SLGetDataFromWCFRIA项目“添加服务引用”即引用刚才我们编写的WCF服务。


第十步：添加一个UserInfo的实体类集合。代码如下：

/// <summary>
/// 用户实体类
/// </summary>
public class UserInfo
{
private string _ID;
private string _UserName;
private string _UserAddr;
private string _UserTel;

public string ID
{
get { return _ID; }
set { _ID = value; }
}

public string UserName
{
get { return _UserName; }
set { _UserName = value; }
}

public string UserAddr
{
get { return _UserAddr; }
set { _UserAddr = value; }
}

public string UserTel
{
get { return _UserTel; }
set { _UserTel = value; }
}
}

第十一步：点击MainPage.xaml文件，添加一个DataGird控件命名为grShow，在MainPage.xaml.cs文件中编写以下代码获取WCF RIA services读取到的数据库数据：

public partial class MainPage : UserControl
{
public MainPage()
{
InitializeComponent();
//创建一个代理类的实例
SLWCFRIAClient client = new SLWCFRIAClient();
//调用GetData方法并加载事件
client.GetDataAsync();
client.GetDataCompleted += new EventHandler<GetDataCompletedEventArgs>(client_GetDataCompleted);
}
public  List<UserInfo> userList = new List<UserInfo>();
void client_GetDataCompleted(object sender, GetDataCompletedEventArgs e)
{
using (XmlReader xReader = XmlReader.Create(new StringReader(e.Result)))
{
//XmlReader读取XML数据
while (xReader.ReadToFollowing("Table"))
{
xReader.ReadToDescendant("ID");
string id = xReader.ReadElementContentAsString();
xReader.ReadToNextSibling("UserName");
string username = xReader.ReadElementContentAsString();

xReader.ReadToNextSibling("UserAddr");
string useraddr = xReader.ReadElementContentAsString();

xReader.ReadToNextSibling("UserTel");
string usertel = xReader.ReadElementContentAsString();
//实例化类并添加进实体类List<>
UserInfo uinfo = new UserInfo(){ID=id, UserName=username,UserAddr=useraddr,UserTel=usertel};
userList.Add(uinfo);
}
this.grShow.ItemsSource = userList;
}

}
}

最后我们看最后的效果图，本实例采用VS2010+Silverlight 4.0+MS SQL SERVER 2008，点击 SLGetDataFromWCFRIA.rar 下载本实例源码和示例数据库。