异常排序c#

本文关键字：排序 异常 | 更新日期: 2023-09-27 18:19:19

当它到达最后一行时，我将低于"索引超出范围"。有谁能帮我找出问题所在吗? 

List<string> mailInfoList = new List<string>();
if (ds.Tables[0].Rows.Count > 0)
{
    foreach (DataRow row in ds.Tables[0].Rows)
    {
        string strSubject = row["Subject"].ToString();
        string strEmailFrom =row["EmailFrom"].ToString();
        string strEmailTo =row["EmailTo"].ToString();
        string strEmailCC =row["EmailCc"].ToString();
        string strEmailContent=row["EmailContent"].ToString();
        string strCreatedOn =row["CreatedOn"].ToString();
        mailInfoList.Add(strSubject);
        mailInfoList.Add(strEmailFrom);
        mailInfoList.Add(strEmailTo);
        mailInfoList.Add(strEmailCC);
        mailInfoList.Add(strEmailContent);
        mailInfoList.Add(strCreatedOn);
        var newList = mailInfoList.OrderBy(x => x[1]).ThenBy(x => x[2]).ToList();
    }
}

异常排序c#

这里。Try thing instead:

var mailInfoList = new List<Tuple<string, string, string, string, string, DateTime>>();
if (ds.Tables[0].Rows.Count > 0)
{
    foreach (DataRow row in ds.Tables[0].Rows)
    {
        string strSubject = row["Subject"].ToString();
        string strEmailFrom = row["EmailFrom"].ToString();
        string strEmailTo = row["EmailTo"].ToString();
        string strEmailCC = row["EmailCc"].ToString();
        string strEmailContent = row["EmailContent"].ToString();
        // Do proper error handling here
        DateTime strCreatedOn = DateTime.Parse(row["CreatedOn"].ToString());
        mailInfoList.Add(new Tuple<string, string, string, string, string, DateTime>(
            strSubject, strEmailFrom, strEmailTo, strEmailCC, strEmailContent, strCreatedOn
            ));
        var newList = mailInfoList.OrderBy(x => x.Item1).ThenBy(x => x.Item6).ToList();
    }
}

它将按主题然后按创建日期对条目进行排序。只要确保DateTime.Parse不会抛出错误(您也可以使用DateTime.TryParse

)

请注意，在使用OrderBy(x => x[1]) 时，x是指String类型的mailInfoList的每个索引，x[1]是指该索引的第二个字符。

那么你确定List的每个索引的长度至少是1吗?

我建议你使用:

var newList = mailInfoList.where( y => y.lenght > 0).OrderBy(x => x[1]).ThenBy(x => x[2]).ToList();

首先，您需要创建类似于数据表对象的类模型，从您的示例中，它看起来像这样，

public class Emails
{
    public string Subject { get; set; }
    public string EmailFrom { get; set; }
    public string EmailTo { get; set; }
    public string EmailCc { get; set; }
    public string EmailContent { get; set; }
    public DateTime CreatedOn { get; set; }
}

和你的更新代码块变成，

List<Emails> mailInfoList = new List<Emails>();
if (ds.Tables[0].Rows.Count > 0)
{
    foreach (DataRow row in ds.Tables[0].Rows)
    {
        Emails email = new Emails();
        email.Subject = row["Subject"].ToString();
        email.EmailFrom = row["EmailFrom"].ToString();
        email.EmailTo = row["EmailTo"].ToString();
        email.EmailCc = row["EmailCc"].ToString();
        email.EmailContent = row["EmailContent"].ToString();
        email.CreatedOn = Convert.ToDateTime(row["CreatedOn"].ToString());
        mailInfoList.Add(email);
    }
    var newList = mailInfoList.OrderBy(c => c.EmailFrom).ThenBy(n => n.CreatedOn);
}
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