只需将我的代码片段添加到以下文章,以帮助理解内置到CsvHelper中的类型转换器。我需要按以下格式处理日期“yyyyMMdd”,并且它似乎在不使用.net DateTime Parse错误的情况下来回写入CSV:“字符串未被识别为有效的DateTime。”
using (TextWriter writer = new StreamWriter(csvLocaitonAndName))
{
var csvUpdate = new CsvWriter(writer);
csvUpdate.Configuration.TypeConverterCache.AddConverter<DateTime?>(new DateConverter("yyyyMMdd"));
csvUpdate.Configuration.HasHeaderRecord = false;
csvUpdate.WriteRecords(list);
}
public class DateConverter : ITypeConverter
{
private readonly string _dateFormat;
public DateConverter(string dateFormat)
{
_dateFormat = dateFormat;
}
public object ConvertFromString(string text, IReaderRow row, MemberMapData memberMapData)
{
if (!string.IsNullOrEmpty(text))
{
DateTime dt;
DateTime.TryParseExact(text, _dateFormat,
CultureInfo.InvariantCulture,
DateTimeStyles.None,
out dt);
if (IsValidSqlDateTime(dt))
{
return dt;
}
}
return null;
}
public string ConvertToString(object value, IWriterRow row, MemberMapData memberMapData)
{
return ObjectToDateString(value, _dateFormat);
}
public string ObjectToDateString(object o, string dateFormat)
{
if (o == null) return string.Empty;
DateTime dt;
if (DateTime.TryParse(o.ToString(), out dt))
return dt.ToString(dateFormat);
else
return string.Empty;
}
public bool IsValidSqlDateTime(DateTime? dateTime)
{
if (dateTime == null) return true;
DateTime minValue = DateTime.Parse(System.Data.SqlTypes.SqlDateTime.MinValue.ToString());
DateTime maxValue = DateTime.Parse(System.Data.SqlTypes.SqlDateTime.MaxValue.ToString());
if (minValue > dateTime.Value || maxValue < dateTime.Value)
return false;
return true;
}