字符串未被识别为从索引0开始的有效日期时间/未知字词？ [英] String Was Not Recognized As A Valid DateTime / Unknown Word Starting At Index 0?

问题描述

SqlConnection conn = new SqlConnection（ConfigurationManager.ConnectionStrings [dbconnection]。ConnectionString）;

conn.Open（）;

string date = Convert.ToString（ ddlYear.SelectedItem.Value）+/+ Convert.ToString（ddlMonth.SelectedItem.Value）+/+ Convert.ToString（ddlDate.SelectedItem.Value）;

DateTime dt = Convert。 ToDateTime（日期）;

// ddlYear.SelectedValue +/+ ddlMonth.SelectedValue +/+ ddlDate.SelectedValue

SqlCommand cmd = new SqlCommand（@插入OnlineBookingEvent（BookingEvent，BookeventDate，cdt，udt）值

（@ BookingEvent，@ BookeventDate，@ cdt，@ udt），conn）;

cmd.Parameters .AddWithValue（@ BookingEvent，ddlEventName.DataValueField）;

cmd.Parameters.AddWithValue（@ BookeventDate，dt）;

cmd.Parameters.AddWithValue（ @cdt，System.DateTime.Now）;

cmd.Parameters.AddWithValue（@ udt，System.DateTime.Now）;

cmd.ExecuteNonQuery（） ;

解决方案

如果您的每个下拉列表都有一个数值，那么为什么要通过这种环形交叉方法将其构建为DateTime？为什么转换依赖于当前系统设置（您不参考或检查）通过构建字符串？



而是尝试：

 DateTime dt =  new  DateTime（（ int ） ddlYear.SelectedItem.Value，（ int ）ddlMonth.SelectedItem.Value，（ int ）ddlDate.SelectedItem。价值）; 

这样，没有字符串，没有解释 - 只是清晰度（以及更可读的代码才能启动）？

Convert.ToDateTime考虑您的系统日期时间格式。



例如，假设您的机器日期时间格式为dd / MM / yyy 并且你的字符串包含以yyyy / MM / dd表示的日期时间，你将得到上述错误。





更改系统日期时间格式。

或者使用以下代码然后执行exec来更改应用程序DateFormat上面的代码

 CultureInfo current = Thread.CurrentThread.CurrentCulture.Clone（）as CultureInfo; 
 DateTimeFormatInfo ObjPriDateTimeFormat = DateTimeFormatInfo.CurrentInfo.Clone（）as DateTimeFormatInfo; 
 ObjPriDateTimeFormat.ShortDatePattern =yyyy / MM / dd; 
 current.DateTimeFormat = ObjPriDateTimeFormat; 
 Thread.CurrentThread.CurrentCulture = current; 

SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["dbconnection"].ConnectionString);
conn.Open();
string date = Convert.ToString(ddlYear.SelectedItem.Value) + "/" + Convert.ToString(ddlMonth.SelectedItem.Value) + "/" + Convert.ToString(ddlDate.SelectedItem.Value);
DateTime dt = Convert.ToDateTime(date);
// ddlYear.SelectedValue + "/" + ddlMonth.SelectedValue + "/" + ddlDate.SelectedValue
SqlCommand cmd = new SqlCommand(@"insert into OnlineBookingEvent(BookingEvent,BookeventDate,cdt,udt)values
(@BookingEvent,@BookeventDate,@cdt,@udt)", conn);
cmd.Parameters.AddWithValue("@BookingEvent", ddlEventName.DataValueField);
cmd.Parameters.AddWithValue("@BookeventDate",dt);
cmd.Parameters.AddWithValue("@cdt", System.DateTime.Now);
cmd.Parameters.AddWithValue("@udt", System.DateTime.Now);
cmd.ExecuteNonQuery();

解决方案

If you have a Value to each of your drop down lists which is numeric, why are you building it into a DateTime by such a roundabout method? Why do conversions which are dependant on the current system settings (which you don;t reference or check) by building a string at all?

Instead try:

DateTime dt = new DateTime((int) ddlYear.SelectedItem.Value, (int) ddlMonth.SelectedItem.Value, (int) ddlDate.SelectedItem.Value);

That way, there is no strings, not interpretation - just clarity (and more readable code to boot)?

Convert.ToDateTime considers your system datetime format.

For instance lets say your machine date time format is "dd/MM/yyy" and your string contain date time in "yyyy/MM/dd" you will get above error.


Either change system date time format.
Or change Application DateFormat using following code and then execute above code

CultureInfo current = Thread.CurrentThread.CurrentCulture.Clone() as CultureInfo;
DateTimeFormatInfo ObjPriDateTimeFormat = DateTimeFormatInfo.CurrentInfo.Clone() as DateTimeFormatInfo;
ObjPriDateTimeFormat.ShortDatePattern="yyyy/MM/dd";
current.DateTimeFormat = ObjPriDateTimeFormat;
Thread.CurrentThread.CurrentCulture = current;

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