生活所迫在来问个问题。。哎。都不好意思了

[kmiaoer]

Server Error in '/' Application.
--------------------------------------------------------------------------------

Object cannot be cast from DBNull to other types.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidCastException: Object cannot be cast from DBNull to other types.

Source Error:


Line 37: txtSp_content.Text = dt.Rows[0][3].ToString();
Line 38: txtSp_cost.Text = dt.Rows[0][4].ToString().Trim();
Line 39: txtSp_time.Text= Convert.ToDateTime(dt.Rows[0][5]).ToString("yyyy-MM-dd");
Line 40: ddlSp_xianshi.SelectedValue = dt.Rows[0][6].ToString();
Line 41: }


Source File: f:\usr\cn30120\admin\daili\edit.aspx.cs Line: 39

Stack Trace:


[InvalidCastException: Object cannot be cast from DBNull to other types.]
System.DBNull.System.IConvertible.ToDateTime(IFormatProvider provider) +54
System.Convert.ToDateTime(Object value) +29
admin_daili_edit.Bin(String strsql) in f:\usr\cn30120\admin\daili\edit.aspx.cs:39
admin_daili_edit.Page_Load(Object sender, EventArgs e) in f:\usr\cn30120\admin\daili\edit.aspx.cs:24
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +15
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +34
System.Web.UI.Control.OnLoad(EventArgs e) +99
System.Web.UI.Control.LoadRecursive() +47
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint


他老报 转换这儿出问题 Line 39: txtSp_time.Text= Convert.ToDateTime(dt.Rows[0][5]).ToString("yyyy-MM-dd");

请高手指点。。

[sendling]

加了 一个问号。。问高手这个是什么原因
==============================
顶不知道，

[typ668]

学习

[antoniusguo]

异常页面已经说明了问题
Object cannot be cast from DBNull
=============================================

System.Object date = dt.Rows[0][5];
if(System.DBNull.Value != date)
txtSp_time.Text = Convert.ToDateTime(date).ToString("yyyy-MM-dd");

[mysky0103]

dt.Rows[0][5] 看一下这个值 没空值

[rtsp]

if(dt.Rows[0][5]==null || dt.Rows[0][5]=="")
{
txtSp_time.Text= "";
}
else
{
txtSp_time.Text= Convert.ToDateTime(dt.Rows[0][5]).ToString("yyyy-MM-dd");
}

[jiaoke]

先判断一下dt.Rows[0][5]是不是为空。
如果格式不正确也会报错的

[kmiaoer]

问题招到了。。是 地址栏自动加了 一个 问号


我发现我打开所有的网站，他们地址后面都加了 一个问号。。问高手这个是什么原因