如何在每行的末尾添加文本vb.net

Question

我正在開發一個VB.NET程序（2013），該程序適用於本地數據庫（sql server 2008 R2）， 該程序正在轉換數據庫表爲文本文件， 所以如何每行的在該文本文件， 感謝每行末尾的最後一個域之後添加一些文字，很遺憾，我的英語

If mytable.HasRows Then 
       Dim outputStream As StreamWriter = New StreamWriter(FileName & "table.txt", True, GetEncoding) 
       Dim row As Integer = 0 
       myConnection.open() 
       Do While mytable.Read      
        Dim header As Integer = 0 
        Dim counter As Integer = 0 
        Dim fieldCount As Integer = mytable.FieldCount - 1 

        While counter <= fieldCount 
         If counter = 0 Then 
          outputStream.Write("None ,") 
         End If 
         If counter = 3 Then 
          outputStream.Write("123456 ,") 
         End If 
         If counter = 7 Then 
          outputStream.Write("None ,") 
         End If 

         If counter <> fieldCount Then 
          outputStream.Write(mytable(counter).ToString() & ",") 
         Else 
          outputStream.WriteLine(mytable(counter).ToString()) 
         End If 
         counter += 1 
        End While 
        row += 1 

       Loop 
       mytable.Close() 
       outputStream.Close() 
       myConnection.Close() 
      End If 

Answer 1

使用您所提供的例子，你可以替換

    If counter <> fieldCount Then 
         outputStream.Write(mytable(counter).ToString() & ",") 
        Else 
         outputStream.WriteLine(mytable(counter).ToString()) 
        End If 

With：

    If counter <> fieldCount Then 
         outputStream.Write(mytable(counter).ToString() & ",") 
        Else 
         outputStream.WriteLine(mytable(counter).ToString() & "What ever you want to write") 
        End If 

Answer 2

這裏是你的問題的回答代碼的重構：

Imports System.Data.SqlClient 
Imports System.Data 
Public Class Class1 
    Public Sub Writefile() 
     Dim ConnectionString As String = "" 
     Using cnn As New SqlConnection(ConnectionString) 
      cnn.Open() 
      Using cmd As SqlCommand = cnn.CreateCommand 
       cmd.CommandType = System.Data.CommandType.Text 
       cmd.CommandText = "SELECT * FROM SomeTable" 
       Using da As New SqlDataAdapter 
        Using ds As New DataSet 
         da.Fill(ds) 
         Using sw As New System.IO.StreamWriter("C:\myfile.txt") 
          For Each r As DataRow In ds.Tables(0).Rows 
           Dim output As New System.Text.StringBuilder 
           For c As Integer = 0 To ds.Tables(0).Columns.Count - 1 
            Select Case c 
             Case 0 
              output.Append("none ,") 
             Case 3 
              output.Append("123456 ,") 
             Case 7 
              output.Append("none ,") 
             Case Else 
              output.Append(r(c).ToString) 
              If c < ds.Tables(0).Columns.Count - 1 Then 
               output.Append(",") 
              End If 
            End Select 
            sw.WriteLine(output.ToString) 
           Next 
          Next 
         End Using 
        End Using 
       End Using 
      End Using 
     End Using 
    End Sub 
End Class 

此示例包括數據庫調用也是如此。 「使用」塊將確保您的物體被妥善處理和關閉。我一直使用這種模式和模式來編寫文本文件。