使用shell扩展dll，如果用户在文件夹空白区域内单击，如何捕获文件夹路径？
答案 0 :(得分：5)
如果您正在实施shell扩展dll，那么您将IShellExtInit::Initialize(}方法中的路径视为pidlFolder参数。
要确保您的扩展程序还注册了文件夹背景，您还必须在HKCR\Directory\Background\shellex\ContextMenuHandlers
答案 1 :(得分：0)
使用VC ++语言请参考Winmerge源代码 http://sourceforge.net/p/winmerge/code/HEAD/tree/trunk/ShellExtension/
使用C＃请参考这篇文章 http://www.codeproject.com/Articles/174369/How-to-Write-Windows-Shell-Extension-with-NET-Lang 并更新一些地方： 在FileContextMenuExt.cs文件中：
...............
#region Shell Extension Registration
[ComRegisterFunction()]
public static void Register(Type t)
{
try
{
ShellExtReg.RegisterShellExtContextMenuHandler(t.GUID, "Directory",
"CSShellExtContextMenuHandler.FileContextMenuExt Class");
}
catch (Exception ex)
{
Console.WriteLine(ex.Message); // Log the error
throw; // Re-throw the exception
}
}
[ComUnregisterFunction()]
public static void Unregister(Type t)
{
try
{
ShellExtReg.UnregisterShellExtContextMenuHandler(t.GUID, "Directory");
}
catch (Exception ex)
{
Console.WriteLine(ex.Message); // Log the error
throw; // Re-throw the exception
}
}
#endregion
...............
public void Initialize(IntPtr pidlFolder, IntPtr pDataObj, IntPtr hKeyProgID)
{
if (pDataObj == IntPtr.Zero && pidlFolder == IntPtr.Zero)
{
throw new ArgumentException();
}
FORMATETC fe = new FORMATETC();
fe.cfFormat = (short)CLIPFORMAT.CF_HDROP;
fe.ptd = IntPtr.Zero;
fe.dwAspect = DVASPECT.DVASPECT_CONTENT;
fe.lindex = -1;
fe.tymed = TYMED.TYMED_HGLOBAL;
STGMEDIUM stm = new STGMEDIUM();
try
{
if (pDataObj != IntPtr.Zero)
{
// The pDataObj pointer contains the objects being acted upon. In this
// example, we get an HDROP handle for enumerating the selected files
// and folders.
IDataObject dataObject = (IDataObject)Marshal.GetObjectForIUnknown(pDataObj);
dataObject.GetData(ref fe, out stm);
// Get an HDROP handle.
IntPtr hDrop = stm.unionmember;
if (hDrop == IntPtr.Zero)
{
throw new ArgumentException();
}
// Determine how many files are involved in this operation.
uint nFiles = NativeMethods.DragQueryFile(hDrop, UInt32.MaxValue, null, 0);
// This code sample displays the custom context menu item when only
// one file is selected.
if (nFiles == 1)
{
// Get the path of the file.
StringBuilder fileName = new StringBuilder(260);
if (0 == NativeMethods.DragQueryFile(hDrop, 0, fileName,
fileName.Capacity))
{
Marshal.ThrowExceptionForHR(WinError.E_FAIL);
}
this.selectedFile = fileName.ToString();
}
else
{
Marshal.ThrowExceptionForHR(WinError.E_FAIL);
}
}
if (pidlFolder != IntPtr.Zero) {
StringBuilder folderName = new StringBuilder(260);
if (0 == NativeMethods.SHGetPathFromIDList(pidlFolder, folderName))
{
Marshal.ThrowExceptionForHR(WinError.E_FAIL);
}
this.selectedFile = folderName.ToString();
}
}
finally
{
NativeMethods.ReleaseStgMedium(ref stm);
}
}
在ShellExtLib.cs文件中添加以下来源：
[DllImport("shell32.dll")]
public static extern Int32 SHGetPathFromIDList(
IntPtr pidl, // Address of an item identifier list that
// specifies a file or directory location
// relative to the root of the namespace (the
// desktop).
StringBuilder pszPath); // Address of a buffer to receive the file system
在ShellExtLib.cs文件中更新RegisterShellExtContextMenuHandler和UnregisterShellExtContextMenuHandler函数
public static void RegisterShellExtContextMenuHandler(Guid clsid,
string fileType, string friendlyName)
{
if (clsid == Guid.Empty)
{
throw new ArgumentException("clsid must not be empty");
}
if (string.IsNullOrEmpty(fileType))
{
throw new ArgumentException("fileType must not be null or empty");
}
// If fileType starts with '.', try to read the default value of the
// HKCR\<File Type> key which contains the ProgID to which the file type
// is linked.
if (fileType.StartsWith("."))
{
using (RegistryKey key = Registry.ClassesRoot.OpenSubKey(fileType))
{
if (key != null)
{
// If the key exists and its default value is not empty, use
// the ProgID as the file type.
string defaultVal = key.GetValue(null) as string;
if (!string.IsNullOrEmpty(defaultVal))
{
fileType = defaultVal;
}
}
}
}
else {
// Create the key HKCR\<File Type>\shellex\ContextMenuHandlers\{<CLSID>}.
string keyName1 = string.Format(@"{0}\Background\shellex\ContextMenuHandlers\{1}",
fileType, clsid.ToString("B"));
using (RegistryKey key = Registry.ClassesRoot.CreateSubKey(keyName1))
{
// Set the default value of the key.
if (key != null && !string.IsNullOrEmpty(friendlyName))
{
key.SetValue(null, friendlyName);
}
}
}
// Create the key HKCR\<File Type>\shellex\ContextMenuHandlers\{<CLSID>}.
string keyName = string.Format(@"{0}\shellex\ContextMenuHandlers\{1}",
fileType, clsid.ToString("B"));
using (RegistryKey key = Registry.ClassesRoot.CreateSubKey(keyName))
{
// Set the default value of the key.
if (key != null && !string.IsNullOrEmpty(friendlyName))
{
key.SetValue(null, friendlyName);
}
}
}
public static void UnregisterShellExtContextMenuHandler(Guid clsid,
string fileType)
{
if (clsid == null)
{
throw new ArgumentException("clsid must not be null");
}
if (string.IsNullOrEmpty(fileType))
{
throw new ArgumentException("fileType must not be null or empty");
}
// If fileType starts with '.', try to read the default value of the
// HKCR\<File Type> key which contains the ProgID to which the file type
// is linked.
if (fileType.StartsWith("."))
{
using (RegistryKey key = Registry.ClassesRoot.OpenSubKey(fileType))
{
if (key != null)
{
// If the key exists and its default value is not empty, use
// the ProgID as the file type.
string defaultVal = key.GetValue(null) as string;
if (!string.IsNullOrEmpty(defaultVal))
{
fileType = defaultVal;
}
}
}
}
else {
// Remove the key HKCR\<File Type>\shellex\ContextMenuHandlers\{<CLSID>}.
string keyName1 = string.Format(@"{0}\Background\shellex\ContextMenuHandlers\{1}",
fileType, clsid.ToString("B"));
Registry.ClassesRoot.DeleteSubKeyTree(keyName1, false);
}
// Remove the key HKCR\<File Type>\shellex\ContextMenuHandlers\{<CLSID>}.
string keyName = string.Format(@"{0}\shellex\ContextMenuHandlers\{1}",
fileType, clsid.ToString("B"));
Registry.ClassesRoot.DeleteSubKeyTree(keyName, false);
}