动态更改EF的DBContext的连接字符串问题

[taobaoyes]

db.Database.Connection.ConnectionString=“metadata=res://*/poctdb.csdl|res://*/poctdb.ssdl|res://*/poctdb.msl;provider=System.Data.SqlClient;provider connection string="data source=192.168.10.110;initial catalog=db;user id=username;password=123456;MultipleActiveResultSets=True;App=EntityFramework"”
这个出错，提示不支持关键字metadata，


db.Database.Connection.ConnectionString=“data source=192.168.10.110;initial catalog=192.168.10.110;user id=username;password=123456;MultipleActiveResultSets=True;App=EntityFramework“
这个正常

为什么会这样啊