/// <summary>
/// Shows the folder browser dialog box with the specified owner window.
/// </summary>
protected override bool RunDialog(IntPtr hWndOwner)
{
IntPtr pidlRoot = IntPtr.Zero;
bool flag = false;
// Get the IDL for the specific startLocation. e.g. Environment.SpecialFolder.Desktop
NativeWindowCommon.SHGetSpecialFolderLocation(hWndOwner, (int)this.rootFolder, ref pidlRoot);
if (pidlRoot == IntPtr.Zero)
{
// Get the IDL for the default startLocation.
NativeWindowCommon.SHGetSpecialFolderLocation(hWndOwner, 0, ref pidlRoot);
if (pidlRoot == IntPtr.Zero)
{
throw new InvalidOperationException();
}
}
int flags = GetFlags();
if ((flags & (int)NativeWindowCommon.BffStyles.NewDialogStyle) != 0)
{
if (System.Threading.ApartmentState.MTA == Application.OleRequired())
{
flags = flags & (~(int)NativeWindowCommon.BffStyles.NewDialogStyle);
}
}
IntPtr pidl = IntPtr.Zero;
IntPtr hglobal = IntPtr.Zero;
try
{
hglobal = Marshal.AllocHGlobal((int)(MAX_PATH * Marshal.SystemDefaultCharSize));
this.callback = new NativeWindowCommon.BrowseCallbackProc(this.FolderBrowserDialog_BrowseCallbackProc);
NativeWindowCommon.BROWSEINFO lpbi = new NativeWindowCommon.BROWSEINFO
{
pidlRoot = pidlRoot,
hwndOwner = hWndOwner,
pszDisplayName = hglobal,
lpszTitle = this.descriptionText,
ulFlags = flags,
lpfn = this.callback,
lParam = IntPtr.Zero,
iImage = 0
};
// Show the dialog.
pidl = NativeWindowCommon.SHBrowseForFolder(ref lpbi);
if (pidl != IntPtr.Zero)
{
// Retrieve the path from the IDList.
StringBuilder sb = new StringBuilder(MAX_PATH * Marshal.SystemDefaultCharSize);
NativeWindowCommon.SHGetPathFromIDList(pidl, sb);
this.selectedPathNeedsCheck = true;
this.selectedPath = sb.ToString();
flag = true;
}
}
finally
{
NativeWindowCommon.IMalloc malloc = GetSHMalloc();
//Free the memory allocated for getting the ID list for the specific startLocation.
malloc.Free(pidlRoot);
if (pidl != IntPtr.Zero)
{
//Free the memory allocated for getting the ID list for the showing the SHBrowseForFolder.
malloc.Free(pidl);
}
// Free the buffer you've allocated on the global heap.
if (hglobal != IntPtr.Zero)
{
Marshal.FreeHGlobal(hglobal);
}
//Reset the callback function to null.
this.callback = null;
}
return(flag);
}