1、运行环境：Visual studio2005
调试时无错，而连接数据库时报错：
异常详细信息: System.InvalidOperationException: ConnectionString 属性尚未初始化
2、源错误(250):
行 248: try
行 249: {
行 250: myConnection.Open();
行 251: myCommand.ExecuteNonQuery();
行 252: myConnection.Close();
堆栈跟踪:
[InvalidOperationException: ConnectionString 属性尚未初始化。]
System.Data.SqlClient.SqlConnection.PermissionDemand() +46
System.Data.SqlClient.SqlConnectionFactory.PermissionDemand(DbConnection outerConnection) +22
System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +89
System.Data.SqlClient.SqlConnection.Open() +160
Bid.Person.Login(String strEmail, String strPassword) in e:\Visual Studio 2005\WebSites\WebSite4\App_Code\Person.cs:250
Default_aspx.btnSubmit_Click(Object sender, EventArgs e) in e:\Visual Studio 2005\WebSites\WebSite4\Default.aspx.cs:42
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +75
System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +97
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +7
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +11
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +4921
3、错误源代码段：
SqlConnection myConnection = new SqlConnection(ConfigurationManager.AppSettings[ "ConnectionString "]);
SqlCommand myCommand = new SqlCommand( "sp_person_isp ", myConnection);
HttpContext.Current.Trace.Write( "foo: " + ConfigurationManager.AppSettings[ "ConnectionString "]);
// Mark the Command as a SPROC
myCommand.CommandType = CommandType.StoredProcedure;
// Add Parameters to SPROC
SqlParameter prmEmail = new SqlParameter( "@email ", SqlDbType.VarChar, 255);
prmEmail.Value = emailaddress;
myCommand.Parameters.Add(prmEmail);
SqlParameter prmname = new SqlParameter( "@name ", SqlDbType.VarChar, 255);