windows shell 編程2(瀏覽檔案夾)

Windows Shell 編程，即 Windows 外殼編程。我們所看到的資源管理員以及整個案頭，都是一個 Shell。

我們知道，在win32中是以外殼名字空間的形式來組織檔案系統的，在外殼名字空間裡的每一個對象(注)都實現了一個IShellFolder的介面，通過這個介面我們可以直接查詢或間接得到其他相關的介面。

下面做個程式用於瀏覽檔案夾：

在C#中，我們這樣定義 IShellFolder 介面：

 

代碼

    [ComImport]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    [Guid("000214E6-0000-0000-C000-000000000046")]
public interface IShellFolder {
void ParseDisplayName(
            IntPtr hwnd,
            IntPtr pbc,
            [MarshalAs(UnmanagedType.LPWStr)] string pszDisplayName,
out uint pchEaten,
out IntPtr ppidl,
ref uint pdwAttributes);

        [PreserveSig]
int EnumObjects(IntPtr hWnd, SHCONTF flags, out IntPtr enumIDList);

void BindToObject(
            IntPtr pidl,
            IntPtr pbc,
            [In()] ref Guid riid,
out IShellFolder ppv);

void BindToStorage(
            IntPtr pidl,
            IntPtr pbc,
            [In()] ref Guid riid,
            [MarshalAs(UnmanagedType.Interface)] out object ppv);

        [PreserveSig()]
uint CompareIDs(
int lParam,
            IntPtr pidl1,
            IntPtr pidl2);

void CreateViewObject(
            IntPtr hwndOwner,
            [In()] ref Guid riid,
            [MarshalAs(UnmanagedType.Interface)] out object ppv);

void GetAttributesOf(
uint cidl,
            [In(), MarshalAs(UnmanagedType.LPArray)] IntPtr[] apidl,
ref SFGAO rgfInOut);
        IntPtr GetUIObjectOf(
            IntPtr hwndOwner,
uint cidl,
            [MarshalAs(UnmanagedType.LPArray)] IntPtr[] apidl,
            [In()] ref Guid riid,
out IntPtr rgfReserved);

void GetDisplayNameOf(
            IntPtr pidl,
            SHGNO uFlags,
            IntPtr lpName);

        IntPtr SetNameOf(
            IntPtr hwnd,
            IntPtr pidl,
            [MarshalAs(UnmanagedType.LPWStr)] string pszName,
           SHGNO uFlags);
    }

案頭是最頂級的檔案夾，外殼名字空間中其他各項都可以用從案頭開始的 PIDL 加以表示。

 可以通過 API  SHGetDesktopFolder擷取“案頭”的 PIDL 和其 IShellFolder 介面：

代碼

        public static IShellFolder GetDesktopFolder(out IntPtr ppshf)  {
            SHGetDesktopFolder(out ppshf);
            Object obj = Marshal.GetObjectForIUnknown(ppshf);
return (IShellFolder)obj;
        }

 

下面是程式調用的代碼：

代碼

        private void Form1_Load(object sender, EventArgs e){

//獲得案頭 PIDL
            IntPtr desktopPtr;
            IShellFolder desktop = API.GetDesktopFolder(out desktopPtr);

//擷取 C 盤的 PIDL
            string FolderPath = @"C:\";
            IntPtr Pidl = IntPtr.Zero;
            IShellFolder Root;
uint i, j = 0;
            desktop.ParseDisplayName(Handle, IntPtr.Zero, FolderPath, out i, out Pidl, ref j);
            desktop.BindToObject(Pidl, IntPtr.Zero, ref Guids.IID_IShellFolder, out Root);
            Marshal.ReleaseComObject(desktop);

//迴圈尋找 C 盤下面的檔案/檔案夾的 PIDL
            IEnumIDList fileEnum = null;
            IEnumIDList folderEnum = null;
            IntPtr fileEnumPtr = IntPtr.Zero;
            IntPtr folderEnumPtr = IntPtr.Zero;
            IntPtr pidlSub;
int celtFetched;

//擷取子檔案夾
            if (Root.EnumObjects(this.Handle, SHCONTF.FOLDERS | SHCONTF.INCLUDEHIDDEN, out fileEnumPtr) == API.S_OK)
            {
                fileEnum = (IEnumIDList)Marshal.GetObjectForIUnknown(fileEnumPtr);
while (fileEnum.Next(1, out pidlSub, out celtFetched) == 0 && celtFetched == API.S_FALSE)
                {
//擷取顯示名稱
                    string name = API.GetNameByPIDL(pidlSub);
                    lvFile.Items.Add(name, 1);
                }
            }

//擷取子檔案
            if (Root.EnumObjects(this.Handle, SHCONTF.NONFOLDERS | SHCONTF.INCLUDEHIDDEN, out folderEnumPtr) == API.S_OK)
            {
                folderEnum = (IEnumIDList)Marshal.GetObjectForIUnknown(folderEnumPtr);
while (folderEnum.Next(1, out pidlSub, out celtFetched) == 0 && celtFetched == API.S_FALSE)
                {
string name = API.GetNameByPIDL(pidlSub);
                    lvFile.Items.Add(name, 0);
                }
            }

            Marshal.ReleaseComObject(Root);
        }

 

下面是運行後的效果：