求助关于SHMultiFileProperties的问题

[jcqstc]

SHMultiFileProperties的第一个参数是一个自定义的IDataObject。

我个人不是很懂怎么去构造这个IDataObject，虽然参数说明里的那些数据我都有，但就是不知道怎么用。

求一个SHMultiFileProperties的调用例子，特别是有IDataObject的使用。

[effun]

.net已经有IDataObject的实现，只要正确使用就可以了。其实答案很容易找，Google一下前几条就有，参考以下代码：

        [DllImport("shell32.dll", CharSet = CharSet.Auto)]
        private static extern IntPtr SHMultiFileProperties(IDataObject pdtobj, int dwFlags);
        [DllImport("shell32.dll", CharSet = CharSet.Auto)]
        public static extern IntPtr ILCreateFromPath(string path);
        [DllImport("shell32.dll", CharSet = CharSet.None)]
        public static extern void ILFree(IntPtr pidl);
        [DllImport("shell32.dll", CharSet = CharSet.None)]
        public static extern int ILGetSize(IntPtr pidl);

        private void button2_Click(object sender, EventArgs e)
        {

            var data = new DataObject();
            var files = new StringCollection() { @"c:\temp\2010_12_21 9_11_21.jpg", @"c:\temp\2010_12_21 9_09_31.jpg" };
            data.SetFileDropList(files);
            data.SetData("Preferred DropEffect", true, new MemoryStream(new byte[] { 5, 0, 0, 0 }));
            data.SetData("Shell IDList Array", true, CreateShellIDList(files));
            Clipboard.SetDataObject(data, true);

            SHMultiFileProperties(data, 0);
        }

        private static MemoryStream CreateShellIDList(StringCollection filenames)
        {
            // first convert all files into pidls list
            int pos = 0;
            byte[][] pidls = new byte[filenames.Count][];
            foreach (var filename in filenames)
            {
                // Get pidl based on name
                IntPtr pidl = ILCreateFromPath(filename);
                int pidlSize = ILGetSize(pidl);
                // Copy over to our managed array
                pidls[pos] = new byte[pidlSize];
                Marshal.Copy(pidl, pidls[pos++], 0, pidlSize);
                ILFree(pidl);
            }

            // Determine where in CIDL we will start pumping PIDLs
            int pidlOffset = 4 * (filenames.Count + 2);
            // Start the CIDL stream
            var memStream = new MemoryStream();
            var sw = new BinaryWriter(memStream);
            // Initialize CIDL witha count of files
            sw.Write(filenames.Count);
            // Calcualte and write relative offsets of every pidl starting with root
            sw.Write(pidlOffset);
            pidlOffset += 4; // root is 4 bytes
            foreach (var pidl in pidls)
            {
                sw.Write(pidlOffset);
                pidlOffset += pidl.Length;
            }

            // Write the root pidl (0) followed by all pidls
            sw.Write(0);
            foreach (var pidl in pidls) sw.Write(pidl);
            // stream now contains the CIDL
            return memStream;
        }

此代码在Win7下通过测试，但据原作者说在XP下无法正常工作，我没有环境没办法测试，这里有一篇文章可能会有帮助，楼主自己去发现吧。
http://www.zaoxue.com/article/tech-31614.htm

[effun]

上面代码有一行多余的，粘贴过来没有注意看。