c# - 如何格式化文本文件中的数据

Question

我有一个字符串生成器，它包含电子邮件 ID(它包含数千个电子邮件 ID)

StringBuilder sb = new StringBuilder();
foreach (DataRow dr2 in dtResult.Rows)
{
    strtxt = dr2[strMailID].ToString()+";";
    sb.Append(strtxt);    
}

 string filepathEmail = Server.MapPath("Email");
 using (StreamWriter outfile = new StreamWriter(filepathEmail + "\\" + "Email.txt"))
 {
     outfile.Write(sb.ToString());
 }

现在数据像这样存储在文本文件中:

abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com; abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;abc@gmail.com;ab@gmail.com;

但我需要将它们存储为每行应该只有 10 个电子邮件 ID，这样我看起来不错**

知道如何在 .txt 文件中格式化数据吗？任何帮助都会很棒

Answer 1

只需在循环中添加一个计数器并每 10 行附加一个换行符。

int counter = 0;
StringBuilder sb = new StringBuilder();
foreach (DataRow dr2 in dtResult.Rows)
{
   counter++;
   strtxt = dr2[strMailID].ToString()+";";
   sb.Append(strtxt);
   if (counter % 10 == 0)
   {
     sb.Append(Environment.NewLine);
   }
}