C＃寫上我的<code>DataTable</code>在TXT文件

Question

我的DataTable行像40行的DataGridView 顯示我很困惑，爲什麼我的方法只保存One Row在TextFile：

private void SaveBtn_Click(object sender, EventArgs e) 
    { 
     String outputFile; 
     List<String> ListData = new List<String>(); 
     using (SaveFileDialog sfd = new SaveFileDialog()) 
     { 
      sfd.Filter = "Txt File|*.Txt"; 
      if (sfd.ShowDialog() != DialogResult.OK) 
       return; 
      outputFile = sfd.FileName; 
     } 

     DataTable tb = pw.SavedInfo(User_info.UserID); 

     for (int i = 0; i < tb.Rows.Count; i++) 
     { 
      ListData.Add("Name==> " + tb.Rows[i][1].ToString() + " LastName ==> " + tb.Rows[i][2].ToString() + " Email ==> " + tb.Rows[i][3].ToString()); 

     } 

     foreach (String s in ListData) 
     { 
      using (TextWriter Tw = new StreamWriter(outputFile)) 
      { 
       Tw.WriteLine(s); 
      }    
     } 
    } 

難道我錯過了什麼？造成這是一個非常漫長的一天，以保持被聚焦

Answer 1

使用相同StreamWriter：

using (TextWriter Tw = new StreamWriter(outputFile)) 
{ 
    foreach (String s in ListData) 
    { 
     Tw.WriteLine(s);    
    } 
} 

或使用constructor that takes a boo升爲「追加」：

foreach (String s in ListData) 
{ 
    using (TextWriter Tw = new StreamWriter(outputFile, true)) 
    { 
     Tw.WriteLine(s); 
    }    
} 

Answer 2

File.WriteAllLines(outputFile, lisData); 

使用此寫入文件。 File.WriteAllLines Documentation