使用Windows API从富文本控件检索文本的正确方法是什么?

时间:2012-11-23 14:01:32

标签: c# .net winapi pinvoke sendmessage

下面的GetRTF()方法有效,但它只检索元数据:

    public string GetRTF(IntPtr handle)
    {
        string result = String.Empty;
        using (System.IO.MemoryStream stream = new MemoryStream())
        {
            EDITSTREAM editStream = new EDITSTREAM();
            editStream.pfnCallback = new EditStreamCallback(EditStreamProc);
            editStream.dwCookie = stream;

            SendMessage(handle, EM_STREAMOUT, SF_RTF, ref editStream);

            stream.Seek(0, SeekOrigin.Begin);
            using (StreamReader reader = new StreamReader(stream))
            {
                result = reader.ReadToEnd();
            }
        }
        return result;
    }

    private int EditStreamProc(MemoryStream dwCookie, IntPtr pbBuff, int cb, out int pcb)
    {
        pcb = cb;
        byte[] buffer = new byte[cb];
        Marshal.Copy(pbBuff, buffer, 0, cb);
        dwCookie.Write(buffer, 0, cb);
        return 0;
    }

    private delegate int EditStreamCallback(MemoryStream dwCookie, IntPtr pbBuff, int cb, out int pcb);

    [StructLayout(LayoutKind.Sequential)]
    private struct EDITSTREAM
    {
        public MemoryStream dwCookie;
        public int dwError;
        public EditStreamCallback pfnCallback;
    }

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    private static extern IntPtr SendMessage(IntPtr hwnd, uint msg, uint wParam, ref EDITSTREAM lParam);

    private const int WM_USER = 0x0400;
    private const int SF_RTF = 2;
    private const int EM_STREAMOUT = WM_USER + 74;

因此,当我使用富文本控件的句柄调用GetRTF()时,返回值为:

     {\rtf1\ansi\ansicpg1252\deff0\nouicompat\deflang1033{\fonttbl{\f0\fnil\fprq2\fcharset0 Tahoma;}}{\colortbl ;\red59\green59\blue59;}{\*\generator Riched20 14.0.6015.1000;}{\*\mmathPr\mwrapIndent1440}\viewkind4\uc1\pard\cf1\f0\fs17{\pict\wmetafile0}}

但这不是Rich Text Control显示的文本(它只是一个电子邮件地址)。

检索我正在寻找的数据的正确方法是什么?

1 个答案:

答案 0 :(得分:1)

您的代码已经检索了所有数据。这是控件内容的RTF表示。没有文本,因为您的控件中没有任何文本。它似乎只包含图元文件矢量图像。

如果您向该控件发送WM_GETTEXT消息以获取纯文本,那么您什么都不会回来。因为控件不包含文本,只包含图像。