c#打开数据库连接池的工作机制_C#数据库连接池

using System.Data.SqlClient;

using System.Collections;

///

/// ConnectionPool 的摘要说明

///

public class ConnectionPool

{

private static ConnectionPool cpool = null;//池管理对象

private static Object objlock = typeof(ConnectionPool);//池管理对象实例

private int size = 10;//池中连接数

private int useCount = 0;//已经使用的连接数

private ArrayList pool = null;//连接保存的集合

private String ConnectionStr = "";//连接字符串

public ConnectionPool()

{

//

// TODO: 在此处添加构造函数逻辑

//

ConnectionStr = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

size = 100;

pool = new ArrayList();

}

//创建获取连接池对象

public static ConnectionPool getPool()

{

lock (objlock)

{

if (cpool == null)

{

cpool = new ConnectionPool();

}

return cpool;

}

}

//获取池中的连接

public SqlConnection getConnection()

{

lock (pool)

{

SqlConnection tmp = null;

if (pool.Count > 0)

{

tmp = (SqlConnection)pool[0];

pool.RemoveAt(0);

//不成功

if (!isUserful(tmp))

{

//可用的连接数据已去掉一个

useCount--;

tmp = getConnection();

}

}

else

{

//可使用的连接小于连接数量

if (useCount < size)

{

try

{

//创建连接

SqlConnection conn = new SqlConnection(ConnectionStr);

conn.Open();

useCount++;

tmp = conn;

}

catch (Exception e)

{

}

}

}

return tmp;

}

}

//关闭连接,加连接回到池中

public void closeConnection(SqlConnection con)

{

lock (pool)

{

if (con != null)

{

pool.Add(con);

}

}

}

//目的保证所创连接成功,测试池中连接

private bool isUserful(SqlConnection con)

{

//主要用于不同用户

bool result = true;

if (con != null)

{

string sql = "select 1";//随便执行对数据库操作

SqlCommand cmd = new SqlCommand(sql, con);

try

{

{

cmd.ExecuteScalar().ToString();

}

catch

{

result = false;

}

}

return result;

}

}

//使用连接后的连接获取方法 //获取连接时，就不用创建连接直接从池中获取数据         string strsql = "select * from Chapter";         SqlDataAdapter sqldap = new SqlDataAdapter(strsql, ConnectionPool.getPool().getConnection());         DataSet set = new DataSet();         sqldap.Fill(set);         GridView1.DataSource = set.Tables[0].DefaultView;         GridView1.DataBind();