未提示错误，但是运行时出错

Question

异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。

堆栈跟踪: *
[NullReferenceException: 未将对象引用设置到对象的实例。]
studentregister.btnSubmit_Click(Object sender, EventArgs e) +84
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +118
System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +112
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5563

怎么破？在线等！急！

Answer 1

studentregister.btnSubmit_Click(Object sender, EventArgs e) +84

看着事件处理函数，在这里打断点，应该是引用到Null值的变量，调用ToString或者其他方法导致的