如果把从页面控件输入的日期，转换成日期型数据并进行数据查询

[vainwords]

我用
start_date = "";
convert.todatetime(start_date); 怎么总是报错呀

[nycun]

start_date不可以为空呢。

还有大小写哦

[vainwords]

string start = start_year.SelectedValue + "-" + start_month.SelectedValue + "-" + start_day.SelectedValue;
string end = end_year.SelectedValue+"-"+end_month.SelectedValue+"-"+end_day.SelectedValue;
DateTime start_date = new DateTime();
start_date = Convert.ToDateTime(start.ToString());
DateTime end_date = new DateTime();
end_date = Convert.ToDateTime(end.ToString());

[china2001ok]

不是还有小时 和分秒吗？

[xueqs]

start_date不可以为空

[net_boy]

string start = start_year.SelectedValue + "-" + start_month.SelectedValue + "-" + start_day.SelectedValue;
string end = end_year.SelectedValue+"-"+end_month.SelectedValue+"-"+end_day.SelectedValue;
DateTime start_date = new DateTime();
start_date = Convert.ToDateTime(start.ToString());
DateTime end_date = new DateTime();
end_date = Convert.ToDateTime(end.ToString());
string start_string = start_date.ToShortDateString();
string end_string = end_date.ToShortDateString();