回应 Marc F 的帖子 - 我已将 VB.Net 转换为 C#
public enum GW
{
HWNDFIRST = 0,
HWNDLAST = 1,
HWNDNEXT = 2,
HWNDPREV = 3,
OWNER = 4,
CHILD = 5,
ENABLEDPOPUP = 6
}
[System.Runtime.InteropServices.DllImport("user32.dll", EntryPoint = "SendMessageW", ExactSpelling = true, CharSet = System.Runtime.InteropServices.CharSet.Ansi, SetLastError = true)]
public static extern IntPtr SendMessageW(IntPtr hWnd, uint msg, int wParam, [MarshalAs(UnmanagedType.LPWStr)] string lParam);
[System.Runtime.InteropServices.DllImport("user32.dll", EntryPoint = "FindWindowExW", ExactSpelling = true, CharSet = System.Runtime.InteropServices.CharSet.Ansi, SetLastError = true)]
public static extern IntPtr FindWindowExW(IntPtr hWndParent, IntPtr hWndChildAfter, [MarshalAs(UnmanagedType.LPWStr)] string lpszClass, [MarshalAs(UnmanagedType.LPWStr)] string lpszWindow);
[System.Runtime.InteropServices.DllImport("user32", EntryPoint = "GetWindow", ExactSpelling = true, CharSet = System.Runtime.InteropServices.CharSet.Ansi, SetLastError = true)]
public static extern UInt32 GetWindow(IntPtr hwnd, UInt32 wCmd);
[System.Runtime.InteropServices.DllImport("user32", EntryPoint = "GetDesktopWindow", ExactSpelling = true, CharSet = System.Runtime.InteropServices.CharSet.Ansi, SetLastError = true)]
public static extern IntPtr GetDesktopWindow();
[System.Runtime.InteropServices.DllImport("user32", EntryPoint = "GetClassNameA", ExactSpelling = true, CharSet = System.Runtime.InteropServices.CharSet.Ansi, SetLastError = true)]
public static extern int GetClassName(IntPtr hwnd, System.Text.StringBuilder lpClassName, int nMaxCount);
private void FolderBrowserDialog_EnsureVisible(FolderBrowserDialog FB, IntPtr _Owner)
{
IntPtr hwnd = System.IntPtr.Zero;
System.Text.StringBuilder sClassname = new System.Text.StringBuilder(256);
Thread.Sleep(50); //necessary to let FolderBrowserDialog construct its window
hwnd = GetDesktopWindow(); //Desktop window handle.
hwnd = (System.IntPtr)GetWindow(hwnd, (UInt32)GW.CHILD); //We will find all children.
while (!(hwnd == (System.IntPtr)0))
{
if (GetWindow(hwnd, (UInt32)GW.OWNER) == (UInt32)_Owner) //If one window is owned by our main window...
{
GetClassName(hwnd, sClassname, 255);
if (sClassname.ToString() == "#32770") //Check if the class is FolderBrowserDialog.
{
break; //Then we found it.
}
}
hwnd = (System.IntPtr)GetWindow(hwnd, (UInt32)GW.HWNDNEXT); //Next window.
} //If no found then exit.
if (hwnd == (System.IntPtr)0)
{
return;
}
IntPtr hChild = (System.IntPtr)0;
IntPtr hTreeView = (System.IntPtr)0;
int i = 0;
do
{
i += 1;
if (i > 1000) //Security to avoid infinite loop.
{
return;
}
hChild = FindWindowExW(hwnd, hChild, null, null); //Look for children windows of FolderBrowserDialog.
hTreeView = FindWindowExW(hChild, (System.IntPtr)0, "SysTreeView32", null); //Look for treeview of FolderBrowserDialog.
Thread.Sleep(5); //delay necessary because FolderBrowserDialog is in construction, then treeview maybe not yet exist.
} while (hTreeView == (System.IntPtr)0);
if (SendMessageW(hwnd, 0x46A, 1, FB.SelectedPath) == (System.IntPtr)0) //Send message BFFM_SETEXPANDED to FolderBrowserDialog.
{
SendMessageW(hTreeView, 0x7, 0, null); //Send message WM_SETFOCUS to the treeeview.
}
}
对此进行了测试，它工作正常。确保引用 System.Runtime.InteropServices、System.Threading、一个 System.Threading.Tasks
