在多行文本框中以粗體顯示VB的特定行文本

Question

我在vb.net中編寫了一個提醒程序，該程序讀取一個文本文件並顯示日期條目從今天到今天的14天。我希望今天的日期以粗體顯示。如果讓我用一個文本框，而不是RTF文本框有什麼區別這是我已經試過：

Public Sub getReadFile() 

    ' rtfRead is the name of the TextBox 
rtfRead.Text = Nothing 
' Today, the first read line date 
Dim startDate As Date = Date.Now()           
    ' First dated line to read 
Dim todayDate As String = (GetDateInMyFormat(startDate))      
    ' The last read line date 
Dim endDate As String = (GetDateInMyFormat(DateAdd("d", 14, startDate))) 
    ' The first 4 characters of a line. Are the 4 charcters numbers, i.e. yyyy 
Dim lineStart As Object 
    ' The date at the beginnig of a an entry 
Dim lineDate As String = Nothing 
    ' Are the first 4 charcters of a line numeric = True 
Dim isNum As Boolean = False 
    ' TM_Notes.txt 
Dim readFile As String = Nothing  
Dim oldFont As Font = rtfRead.Font 
Dim boldFont As Font = New Font(rtfRead.Font, FontStyle.Bold) 

Try 
    ' Create an instance of StreamReader to read from a file. 
    ' The using statement also closes the StreamReader. 
    Using sr As New StreamReader("TM_Notes.txt") 
     Dim lineRead As String 

     ' Read and display lines from the file until the end of 
     ' the file is reached. 
     Do 
      lineRead = sr.ReadLine() 

      lineStart = Mid(lineRead, 1, 4) 
      isNum = IsNumeric(lineStart) 

      If isNum = True Then 
       lineDate = GetDateInMyFormat(Mid(lineRead, 1, 10)) 
      End If 

      If lineDate = todayDate Then 
       rtfRead.Font = boldFont 
      Else 
       rtfRead.Font = oldFont 
      End If 

      If Not (lineRead Is Nothing) And isNum = False And lineDate <= endDate Then 
       readFile = readFile + lineRead & vbCrLf 
      ElseIf lineDate >= todayDate And lineDate <= endDate Then 
       readFile = readFile + lineRead & vbCrLf 
      End If 

     Loop Until lineRead Is Nothing 
    End Using 

    rtfRead.Text = readFile 

Catch ex As Exception 
    ' Let the user know what went wrong. 
    Console.WriteLine("The file could not be read:") 
    Console.WriteLine(ex.Message) 
End Try 
End Sub 

我沒有得到任何錯誤，但今天的日期是不是在大膽。

今天是02-11，那麼測試字符串行應該是粗體。

2014年2月11日：測試字符串

2014年2月12日：測試字符串2

UPDATE

我已經改變爲格式文本框，並更新了我的代碼示例以反映我的代碼更改。我還沒有變得粗體

Answer 1

這裏是函數...你傳遞你想要找到的文本和格式（粗體或斜體 - 1或2）。這工作真的很好，如果您願意，還可以擴大此項以添加顏色。我希望你找到這個有用的，快樂的編碼！

'Pass in a 1 or 2; one is bold the other is italic' 
Private Function FormatText(ByVal TextToFormat As String, ByVal TextFormat As Integer) 
    Dim count As New List(Of Integer)() 
    For i As Integer = 0 To rText.Text.Length - 1 
     If rText.Text.IndexOf(TextToFormat, i) <> -1 Then 
      'If the word is found add the index to the list 
      count.Add(rText.Text.IndexOf(TextToFormat, i)) 
     End If 
    Next 

    Try 
     For i As Integer = 0 To count.Count - 1 
      rText.[Select](count(i), TextToFormat.Length) 
      Select Case TextFormat 
       Case 1 
        rText.SelectionFont = New Font(rText.Font.FontFamily, rText.Font.Size, FontStyle.Bold) 
       Case 2 
        rText.SelectionFont = New Font(rText.Font.FontFamily, rText.Font.Size, FontStyle.Italic) 
      End Select 
      count.RemoveAt(i) 
     Next 
    Catch 
    End Try 
    Return Nothing 
End Function