异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。源错误: 执行当前 Web 请求期间生成了未处理的异常。可以使用下面的异常堆栈跟踪信息确定有关异常原因和发生位置的信息。 堆栈跟踪:
[NullReferenceException: 未将对象引用设置到对象的实例。]
myaspnet.html.html_cartype_6.ReturnMessage(Int32 cartype_id, Int32 types)
myaspnet.html.myhtml_cartype_6.listCarMessage(Int32 cartype_id)
myaspnet.html.myhtml_cartype_6.Button1_Click(Object sender, EventArgs e)
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +108
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +57
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +18
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
System.Web.UI.Page.ProcessRequestMain() +1292这种问题该怎么办,不知道是哪一行错了.
[NullReferenceException: 未将对象引用设置到对象的实例。]
myaspnet.html.html_cartype_6.ReturnMessage(Int32 cartype_id, Int32 types)
myaspnet.html.myhtml_cartype_6.listCarMessage(Int32 cartype_id)
myaspnet.html.myhtml_cartype_6.Button1_Click(Object sender, EventArgs e)
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +108
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +57
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +18
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
System.Web.UI.Page.ProcessRequestMain() +1292这种问题该怎么办,不知道是哪一行错了.
DataTable dt=html_cartype_6.ReturnCartypeBiaojiao(cartype_id,types); if (dt.Rows.Count>0)//我一步一步调试,最后发现这儿有问题 System.NullReferenceException: 未将对象引用设置到对象的实例。{}