与使用CrLf行结尾的TextBox控件相对，RichTextBox控件使用Lf行结尾。我不想要那个。我需要一致性。我需要一个使用 CrLf 行结尾的RichTextBox控件。
我在反射器中打开控件，注意到Text属性的getter调用了以下函数：
Private Function StreamOut(ByVal flags As Integer) As String
'...
Me.StreamOut(data, flags, False)
'...
End Function
最终致电：
Private Sub StreamOut(ByVal data As Stream, ByVal flags As Integer, ByVal includeCrLfs As Boolean)
'...
Dim es As New EDITSTREAM
'...
ElseIf includeCrLfs Then
num = (num Or &H20)
Else
'...
es.dwCookie = DirectCast(num, IntPtr)
'...
End Sub
正如您所看到的，includeCrLfs参数将始终为False。
所以我将控件子类化并拦截了EM_STREAMOUT消息。此消息的LParam包含指向EDITSTREAM结构的指针。我在上面的函数中添加了&H20标志，但这没有用。 Text属性开始返回空字符串。我相信我可能必须删除/附加其他标志，但我不知道哪些标志。此外，MSDN不提供除应用程序定义的值之外的任何提示。
dwCookie
指定富编辑控件传递给pfnCallback成员指定的EditStreamCallback回调函数的应用程序定义值。
这是我的子类控件：
Public Class UIRichTextBox
Inherits System.Windows.Forms.RichTextBox
Private Sub EmStreamOut(ByRef m As Message)
Dim es As New EDITSTREAM
es = DirectCast(Marshal.PtrToStructure(m.LParam, GetType(EDITSTREAM)), EDITSTREAM)
If (IntPtr.Size = 4) Then
Dim cookie As Int32 = es.dwCookie.ToInt32()
'cookie = (cookie Or &H20I) '<- Didn't work
es.dwCookie = New IntPtr(cookie)
Else
Dim cookie As Int64 = es.dwCookie.ToInt64()
'cookie = (cookie Or &H20L) '<- Didn't work
es.dwCookie = New IntPtr(cookie)
End If
Marshal.StructureToPtr(es, m.LParam, True)
MyBase.WndProc(m)
End Sub
Protected Overrides Sub WndProc(ByRef m As Message)
Select Case m.Msg
Case EM_STREAMOUT
Me.EmStreamOut(m)
Exit Select
Case Else
MyBase.WndProc(m)
Exit Select
End Select
End Sub
Private Const EM_STREAMOUT As Integer = &H44A
Private Delegate Function EDITSTREAMCALLBACK(ByVal dwCookie As IntPtr, ByVal buf As IntPtr, ByVal cb As Integer, <Out()> ByRef transferred As Integer) As Integer
<StructLayout(LayoutKind.Sequential)> _
Private Class EDITSTREAM
Public dwCookie As IntPtr = IntPtr.Zero
Public dwError As Integer
Public pfnCallback As EDITSTREAMCALLBACK
End Class
End Class
更新
事实证明，这些标志根本没有记录。它们是EM_GETEDITSTYLE和EM_SETEDITSTYLE消息的一部分。但正如你所看到的那样，旗帜已经过时了。
SES_USECRLF 已过时。不要使用。
所以我想我会回到第一个覆盖文本属性的地方。
Public Overrides Property Text() As String
Get
Dim value As String = MyBase.Text
If (Not value Is Nothing) Then
value = value.Replace(ChrW(13), "")
value = value.Replace(ChrW(10), Environment.NewLine)
End If
Return value
End Get
Set(value As String)
MyBase.Text = value
End Set
End Property
答案 0 :(得分：1)
所以我设法使用反射创建了一个可行的解决方案。我确信必须有充分的理由说明为什么SES_USECRLF已经过时，所以请谨慎行事。
Public Class UIRichTextBox
Inherits System.Windows.Forms.RichTextBox
Shared Sub New()
UIRichTextBox.InternalEditStream = GetType(System.Windows.Forms.RichTextBox).GetField("editStream", (BindingFlags.NonPublic Or BindingFlags.Instance))
UIRichTextBox.InternalStreamIn = GetType(System.Windows.Forms.RichTextBox).GetMethod("StreamIn", (BindingFlags.NonPublic Or BindingFlags.Instance), Nothing, New Type() {GetType(System.IO.Stream), GetType(System.Int32)}, Nothing)
UIRichTextBox.InternalStreamOut = GetType(System.Windows.Forms.RichTextBox).GetMethod("StreamOut", (BindingFlags.NonPublic Or BindingFlags.Instance), Nothing, New Type() {GetType(System.IO.Stream), GetType(System.Int32), GetType(System.Boolean)}, Nothing)
End Sub
Public Sub New()
Me.m_includeCrLfs = True
End Sub
<DefaultValue(True), Category("Behavior")> _
Public Property IncludeCrLfs() As Boolean
Get
Return Me.m_includeCrLfs
End Get
Set(value As Boolean)
If (value <> Me.m_includeCrLfs) Then
Me.m_includeCrLfs = value
Me.RecreateHandle()
End If
End Set
End Property
Public Overrides Property [Text]() As String
Get
Dim value As String = Nothing
If (Me.StreamOut(&H11, value)) Then
Return value
End If
Return MyBase.[Text]
End Get
Set(ByVal value As String)
If (Not Me.StreamIn(value, &H11)) Then
MyBase.[Text] = value
End If
End Set
End Property
Private Function StreamIn(ByVal str As String, ByVal flags As Integer) As Boolean
If (((Me.IsHandleCreated AndAlso ((Not Me.IsDisposed) AndAlso (Not Me.Disposing))) AndAlso ((Not str Is Nothing) AndAlso (str.Length > 0))) AndAlso ((Not UIRichTextBox.InternalEditStream Is Nothing) AndAlso (Not UIRichTextBox.InternalStreamIn Is Nothing))) Then
Dim bytes As Byte()
Dim index As Integer = str.IndexOf(ChrW(0))
If (index <> -1) Then
str = str.Substring(0, index)
End If
If ((flags And &H10) <> 0) Then
bytes = Encoding.Unicode.GetBytes(str)
Else
bytes = Encoding.Default.GetBytes(str)
End If
Dim data As New System.IO.MemoryStream()
UIRichTextBox.InternalEditStream.SetValue(Me, data)
data.Write(bytes, 0, bytes.Length)
data.Position = 0
UIRichTextBox.InternalStreamIn.Invoke(Me, New Object() {data, flags})
Return True
End If
Return False
End Function
Private Function StreamOut(ByVal flags As Integer, ByRef result As String) As Boolean
If ((Me.IsHandleCreated AndAlso ((Not Me.IsDisposed) AndAlso (Not Me.Disposing))) AndAlso (Not UIRichTextBox.InternalStreamOut Is Nothing)) Then
Dim data As New System.IO.MemoryStream()
UIRichTextBox.InternalStreamOut.Invoke(Me, New Object() {data, flags, Me.m_includeCrLfs})
data.Position = 0
Dim length As Integer = CInt(data.Length)
Dim str As String = String.Empty
If (length > 0) Then
Dim buffer As Byte() = New Byte(length - 1) {}
data.Read(buffer, 0, length)
If ((flags And &H10) <> 0) Then
str = Encoding.Unicode.GetString(buffer, 0, buffer.Length)
Else
str = Encoding.Default.GetString(buffer, 0, buffer.Length)
End If
If ((Not String.IsNullOrEmpty(str)) AndAlso (str.Chars((str.Length - 1)) = ChrW(0))) Then
str = str.Substring(0, (str.Length - 1))
End If
End If
result = str
Return True
End If
Return False
End Function
Private Shared ReadOnly InternalEditStream As FieldInfo
Private Shared ReadOnly InternalStreamIn As MethodInfo
Private Shared ReadOnly InternalStreamOut As MethodInfo
Private m_includeCrLfs As Boolean
End Class