使用 Windows 范围内的 beta UTF-8 支持功能时在 Winforms 中调整 RTF 时出现的错误

我想我在 Windows 或 .NET 中发现了一个错误，并且正在寻找解决方法。

要重现该问题，请首先启用 Windows 功能“Beta：使用 Unicode UTF-8 获得全球语言支持”。

您可能需要重新启动机器。

现在只需在Winforms/C#中创建两个RichTextBox组件，然后添加事件：

    private void richTextBox1_TextChanged(object sender, EventArgs e)
    {
        string s = richTextBox1.Rtf;
        richTextBox2.Rtf = s;
    }

最后，运行该程序并只需在第一个 RichTextBox 中键入一些内容，当它尝试写入时，它将崩溃并显示消息“文件格式无效”richTextBox2.Rtf。如果禁用 Windows 功能“Beta：使用 Unicode UTF-8 获得全球语言支持”，它不会崩溃。

我在这里考虑两种可能的解决方法：

1：以某种方式在 C# 应用程序中禁用整个“Beta：使用 Unicode UTF-8 实现全球语言支持”功能，并假装它从未启用过。

2：以某种方式编辑 RTF 字符串，以符合新 RTF 在调整其他 RichTextBox 的 RTF 之前应具有的任何未知要求。考虑到第一个 RichTextBox 应该具有完全相同的 RTF，这似乎违反直觉，但无论如何......

************* Exception Text **************
System.ArgumentException: File format is not valid.
at System.Windows.Forms.RichTextBox.StreamIn(Stream data, Int32 flags)
at System.Windows.Forms.RichTextBox.StreamIn(String str, Int32 flags)
at System.Windows.Forms.RichTextBox.set_Rtf(String value)
at unicodeTesting.Form1.richTextBox1_TextChanged(Object sender, EventArgs e) in D:\Code\c#\_tests\unicodeTesting\Form1.cs:line 30
at System.Windows.Forms.Control.OnTextChanged(EventArgs e)
at System.Windows.Forms.TextBoxBase.OnTextChanged(EventArgs e)
at System.Windows.Forms.TextBoxBase.WmReflectCommand(Message& m)
at System.Windows.Forms.TextBoxBase.WndProc(Message& m)
at System.Windows.Forms.RichTextBox.WmReflectCommand(Message& m)
at System.Windows.Forms.RichTextBox.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Microsoft 开源了 WinForms 库，因此您可以自己深入研究源代码：

https://github.com/dotnet/winforms/tree/master/src/System.Windows.Forms/src/System/Windows/Forms https://github.com/dotnet/winforms/tree/master/src/System.Windows.Forms/src/System/Windows/Forms

StreamIn方法位于第3140行https://github.com/dotnet/winforms/blob/master/src/System.Windows.Forms/src/System/Windows/Forms/RichTextBox.cs https://github.com/dotnet/winforms/blob/master/src/System.Windows.Forms/src/System/Windows/Forms/RichTextBox.cs:

 private void StreamIn(string str, int flags)
    {
        if (str.Length == 0)
        {
            // Destroy the selection if callers was setting
            // selection text
            //
            if ((RichTextBoxConstants.SFF_SELECTION & flags) != 0)
            {
                SendMessage(Interop.WindowMessages.WM_CLEAR, 0, 0);
                ProtectedError = false;
                return;
            }
            // WM_SETTEXT is allowed even if we have protected text
            //
            SendMessage(Interop.WindowMessages.WM_SETTEXT, 0, "");
            return;
        }

        // Rather than work only some of the time with null characters,
        // we're going to be consistent and never work with them.
        int nullTerminatedLength = str.IndexOf((char)0);
        if (nullTerminatedLength != -1)
        {
            str = str.Substring(0, nullTerminatedLength);
        }

        // get the string into a byte array
        byte[] encodedBytes;
        if ((flags & RichTextBoxConstants.SF_UNICODE) != 0)
        {
            encodedBytes = Encoding.Unicode.GetBytes(str);
        }
        else
        {
            encodedBytes = Encoding.Default.GetBytes(str);
        }
        editStream = new MemoryStream(encodedBytes.Length);
        editStream.Write(encodedBytes, 0, encodedBytes.Length);
        editStream.Position = 0;
        StreamIn(editStream, flags);
    }

    private void StreamIn(Stream data, int flags)
    {
        // clear out the selection only if we are replacing all the text
        //
        if ((flags & RichTextBoxConstants.SFF_SELECTION) == 0)
        {
            NativeMethods.CHARRANGE cr = new NativeMethods.CHARRANGE();
            UnsafeNativeMethods.SendMessage(new HandleRef(this, Handle), Interop.EditMessages.EM_EXSETSEL, 0, cr);
        }

        try
        {
            editStream = data;
            Debug.Assert(data != null, "StreamIn passed a null stream");

            // If SF_RTF is requested then check for the RTF tag at the start
            // of the file.  We don't load if the tag is not there
            // 
            if ((flags & RichTextBoxConstants.SF_RTF) != 0)
            {
                long streamStart = editStream.Position;
                byte[] bytes = new byte[SZ_RTF_TAG.Length];
                editStream.Read(bytes, (int)streamStart, SZ_RTF_TAG.Length);
                string str = Encoding.Default.GetString(bytes);
                if (!SZ_RTF_TAG.Equals(str))
                {
                    throw new ArgumentException(SR.InvalidFileFormat);
                }

                // put us back at the start of the file
                editStream.Position = streamStart;
            }

            int cookieVal = 0;
            // set up structure to do stream operation
            NativeMethods.EDITSTREAM es = new NativeMethods.EDITSTREAM();
            if ((flags & RichTextBoxConstants.SF_UNICODE) != 0)
            {
                cookieVal = INPUT | UNICODE;
            }
            else
            {
                cookieVal = INPUT | ANSI;
            }
            if ((flags & RichTextBoxConstants.SF_RTF) != 0)
            {
                cookieVal |= RTF;
            }
            else
            {
                cookieVal |= TEXTLF;
            }
            es.dwCookie = (IntPtr)cookieVal;
            es.pfnCallback = new NativeMethods.EditStreamCallback(EditStreamProc);

            // gives us TextBox compatible behavior, programatic text change shouldn't
            // be limited...
            //
            SendMessage(Interop.EditMessages.EM_EXLIMITTEXT, 0, int.MaxValue);



            // go get the text for the control
            // Needed for 64-bit
            if (IntPtr.Size == 8)
            {
                NativeMethods.EDITSTREAM64 es64 = ConvertToEDITSTREAM64(es);
                UnsafeNativeMethods.SendMessage(new HandleRef(this, Handle), Interop.EditMessages.EM_STREAMIN, flags, es64);

                //Assign back dwError value
                es.dwError = GetErrorValue64(es64);
            }
            else
            {
                UnsafeNativeMethods.SendMessage(new HandleRef(this, Handle), Interop.EditMessages.EM_STREAMIN, flags, es);
            }

            UpdateMaxLength();

            // If we failed to load because of protected
            // text then return protect event was fired so no
            // exception is required for the the error
            if (GetProtectedError())
            {
                return;
            }

            if (es.dwError != 0)
            {
                throw new InvalidOperationException(SR.LoadTextError);
            }

            // set the modify tag on the control
            SendMessage(Interop.EditMessages.EM_SETMODIFY, -1, 0);

            // EM_GETLINECOUNT will cause the RichTextBoxConstants to recalculate its line indexes
            SendMessage(Interop.EditMessages.EM_GETLINECOUNT, 0, 0);


        }
        finally
        {
            // release any storage space held.
            editStream = null;
        }
    }

它看起来确实是一个错误，由于它是测试版，所以最好的做法是通过 Microsoft 记录它：https://developercommunity.visualstudio.com https://developercommunity.visualstudio.com

如果您将 RichTextBox 控件类替换为库中的代码，您将能够看到错误发生在哪一行：

System.Windows.Forms.RichTextBox.StreamIn(Stream data, Int32 flags)

Update:

这实际上是一个已知问题，https://social.msdn.microsoft.com/Forums/en-US/28940162-5f7b-4687-af19-1eeef90d3963/richtextboxrtf-setter- throwing-systemargumentexception-file-format-is-not-valid-in-windows？论坛=winforms https://social.msdn.microsoft.com/Forums/en-US/28940162-5f7b-4687-af19-1eeef90d3963/richtextboxrtf-setter-throwing-systemargumentexception-file-format-is-not-valid-in-windows?forum=winforms

已经向微软报告：https://developercommunity.visualstudio.com/content/problem/544623/issue-caused-by-unicode-utf-8-for-world-wide-langu.html https://developercommunity.visualstudio.com/content/problem/544623/issue-caused-by-unicode-utf-8-for-world-wide-langu.html

MSFT 的 Kyle Wang 已将问题范围缩小到操作系统问题：

PC1（操作系统版本 .437 可以重现该问题）：

Env:

Test:

PC2（操作系统版本 .348 无法重现该问题）：

Env:

Test: