Vb.net 为什么当我将文本框值附加到新消息时，它会给我错误的显示？

我想附上发送者的信息和接收者的信息。但是当我使用

Me.MainDisplay.Text = Me.MainDisplay.Text & MessageToDisplay & Environment.NewLine 

消息不会追加，而是显示不正确。例如，我发送

1 2 3 请帮助更改：

If MessageToDisplay = "" Then
    If filename.Folder = "User" Then
        MessageToDisplay = CurrentRecipient + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
    ElseIf filename.Folder = "Recipient" Then
        MessageToDisplay = CurrentUser + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
    End If

Else
    If filename.Folder = "User" Then
        MessageToDisplay = MessageToDisplay + Environment.NewLine + CurrentRecipient + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
    ElseIf filename.Folder = "Recipient" Then
        MessageToDisplay = MessageToDisplay + Environment.NewLine + CurrentUser + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
    End If

End If
Me.MainDisplay.Text = Me.MainDisplay.Text + MessageToDisplay & Environment.NewLine

致：

---

问题标题不是一个自我介绍的地方，也不是把问题的开头几个字放进去的地方。您需要对其进行编辑，并为您的问题提供有意义的摘要。想一想如果你想搜索这个问题，你会在谷歌上输入什么。你的例子没有太大帮助，因为你没有告诉我们哪个是哪个，结果应该是什么。请阅读并采取行动

For Each filename In SortedFilenames
    If filename.Folder = "User" Then
        RecipientFolder = "C:\Users\bele\Desktop\" + CurrentUser + "'sInbox\" + CurrentRecipient + "'sFolder\"
    ElseIf filename.Folder = "Recipient" Then
        RecipientFolder = "C:\Users\bele\Desktop\" + CurrentRecipient + "'sInbox\" + CurrentUser + "'sFolder\"
    End If

    FileContents = My.Computer.FileSystem.ReadAllText(RecipientFolder + filename.Id.ToString("MMddyyyyhhmmss") + ".txt")

    If MessageToDisplay = "" Then
        If filename.Folder = "User" Then
            MessageToDisplay = CurrentRecipient + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
        ElseIf filename.Folder = "Recipient" Then
            MessageToDisplay = CurrentUser + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
        End If

    Else
        If filename.Folder = "User" Then
            MessageToDisplay = MessageToDisplay + Environment.NewLine + CurrentRecipient + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
        ElseIf filename.Folder = "Recipient" Then
            MessageToDisplay = MessageToDisplay + Environment.NewLine + CurrentUser + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
        End If

    End If
    Me.MainDisplay.Text = Me.MainDisplay.Text + MessageToDisplay & Environment.NewLine

    My.Computer.FileSystem.MoveFile(RecipientFolder + filename.Id.ToString("MMddyyyyhhmmss") + ".txt",
                                    "C:\Users\bele\Desktop\" + User + "'sInbox\" + User + "'sReadMessage\" & filename.Id.ToString("MMddyyyyhhmmss") + ".txt")
Next

If MessageToDisplay = "" Then
    If filename.Folder = "User" Then
        MessageToDisplay = CurrentRecipient + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
    ElseIf filename.Folder = "Recipient" Then
        MessageToDisplay = CurrentUser + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
    End If

Else
    If filename.Folder = "User" Then
        MessageToDisplay = MessageToDisplay + Environment.NewLine + CurrentRecipient + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
    ElseIf filename.Folder = "Recipient" Then
        MessageToDisplay = MessageToDisplay + Environment.NewLine + CurrentUser + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
    End If

End If
Me.MainDisplay.Text = Me.MainDisplay.Text + MessageToDisplay & Environment.NewLine

If filename.Folder = "User" Then
    MessageToDisplay = CurrentRecipient + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
ElseIf filename.Folder = "Recipient" Then
    MessageToDisplay = CurrentUser + ": " + FileContents + Environment.NewLine + filename.Id.ToString("MM/dd/yyyy hh:mm:ss")
End If

Me.MainDisplay.Text = Me.MainDisplay.Text + MessageToDisplay & Environment.NewLine