指定的转换无效
string StrSql = "select * from article order by submit_date desc";
using (OleDbConnection Conn = new OleDbConnection(StrCon))
{
Conn.Open();
OleDbCommand cmd = new OleDbCommand(StrSql, Conn);
OleDbDataReader dr = cmd.ExecuteReader();
List<article> list = new List<article>();
while (dr.Read())
{
article Article = new article();
for (int i = 0; i < dr.FieldCount; i++)
{
string fieldName = dr.GetName(i);
if (fieldName == "arti_id")
Article.Arti_id = (int)dr["arti_id"];
if (fieldName == "user_id")
{
Article.User_id = (int)dr["user_id"];
//Article.User_name = UserService.GetUserNameByUserId((int)dr["user_id"]).User_name;//未将对象引用设置到对象的实例
}
if (fieldName == "arti_title")
Article.Arti_title = (string)dr["arti_title"];
if (fieldName == "arti_text")
Article.Arti_text = (string)dr["arti_title"];
if (fieldName == "arti_click")
Article.Arti_click = (int)dr["arti_click"];
if (fieldName == "submit_date")
Article.Submit_date = (DateTime)dr["submit_date"];//运行时此处报错“指定的转换无效”
}
list.Add(Article);
}
dr.Close();
return list;
}
大致知道是转换成access的日期时间类型时问题，求解此处如何能从C# 中转换成为access日期时间类型
[解决办法]
//try one try
string str = dr["submit_date"].ToString();
DateTime = DateTime.Parse(str);
[解决办法]
//Article.User_name = UserService.GetUserNameByUserId((int)dr["user_id"]).User_name;//未将对象引用设置到对象的实例
====》
可能是dr["user_id"]没取到值或者UserService.GetUserNameByUserId((int)dr["user_id"])没得到值。。。
-----------------------
Article.Submit_date = (DateTime)dr["submit_date"];//运行时此处报错“指定的转换无效”
====》
F5.。。看看dr["submit_date"]得到的是个什么
[解决办法]
Article.Submit_date = (DateTime)dr["submit_date"];/
可能为空，建议不要强制转换
