"超时时间已到。在从池中获取连接之前超时时间已过。出现这种情况可能是因为所有池连接都已被使用并已达到最大池大小。"这个问题已经弄了好久了,在音乐站中经常出现,今天才算有了起色.问题的原因是与数据库的连接没有显示关闭,而等系统自动回收是要时间的.解决的方法是改变连接池的大小.在连接字符串的后面加上以下代码:Enlist=true;Pooling=true;Max Pool Size=300;Min Pool Size=0;Connection Lifetime=300;user id=sa;packet size=1000

       各参数含义如下表所示:
NameDefaultDescription
Application Name The name of the application, or '.Net SqlClient Data Provider' if no application name is provided.
AttachDBFilename
-or-
extended properties
-or-
Initial File Name
 The name of the primary file, including the full path name, of an attachable database. The database name must be specified with the keyword 'database'.
Connect Timeout
-or-
Connection Timeout
15The length of time (in seconds) to wait for a connection to the server before terminating the attempt and generating an error.
Connection Lifetime0When a connection is returned to the pool, its creation time is compared with the current time, and the connection is destroyed if that time span (in seconds) exceeds the value specified by connection lifetime. Useful in clustered configurations to force load balancing between a running server and a server just brought on-line.
Connection Reset'true'Determines whether the database connection is reset when being removed from the pool. Setting to 'false' avoids making an additional server round-trip when obtaining a connection, but the programmer must be aware that the connection state is not being reset.
Current Language The SQL Server Language record name.
Data Source
-or-
Server
-or-
Address
-or-
Addr
-or-
Network Address
 The name or network address of the instance of SQL Server to which to connect.
Enlist'true'When true, the pooler automatically enlists the connection in the creation thread's current transaction context.
Initial Catalog
-or-
Database
 The name of the database.
Integrated Security
-or-
Trusted_Connection
'false'Whether the connection is to be a secure connection or not. Recognized values are 'true', 'false', and 'sspi', which is equivalent to 'true'.
Max Pool Size100The maximum number of connections allowed in the pool.
Min Pool Size0The minimum number of connections allowed in the pool.
Network Library
-or-
Net
'dbmssocn'The network library used to establish a connection to an instance of SQL Server. Supported values include dbnmpntw (Named Pipes), dbmsrpcn (Multiprotocol), dbmsadsn (Apple Talk), dbmsgnet (VIA), dbmsipcn (Shared Memory) and dbmsspxn (IPX/SPX), and dbmssocn (TCP/IP).
The corresponding network DLL must be installed on the system to which you connect. If you do not specify a network and you use a local server (for example, "." or "(local)"), shared memory is used.
Packet Size8192Size in bytes of the network packets used to communicate with an instance of SQL Server.
Password
-or-
Pwd
 The password for the SQL Server account logging on.
Persist Security Info'false'When set to 'false', security-sensitive information, such as the password, is not returned as part of the connection if the connection is open or has ever been in an open state. Resetting the connection string resets all connection string values including the password.
Pooling'true'When true, the SQLConnection object is drawn from the appropriate pool, or if necessary, is created and added to the appropriate pool.
User ID The SQL Server login account.
Workstation IDthe local computer nameThe name of the workstation connecting to SQL Server.


     修改过后的数据库连接池应该不会出现以前的问题。