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Can't toggle 'Align icons to grid' on the desktop

Here's the code I'm using:
private void Button_Click(object sender, RoutedEventArgs e) {
SendMessage(GetDesktopWindow(), LVM_ARRANGE, LVA_SNAPTOGRID, 0);
}
public const uint LVM_ARRANGE = 0x1000 + 22;
public const int LVA_SNAPTOGRID = 0x0005;
[DllImport("User32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr GetDesktopWindow();
[DllImport("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, uint msg, int wParam, int lParam);
Nothing happens when I run it. Code is borrowed from https://www.codeproject.com/Messages/1168961/Re-Auto-Arrange-desktop-icons.aspx
Tried different Windows versions too.

This code worked for me. Note that it doesn't appear to change the options, so although it arranges to the grid for me the View->Align Icons To Grid is still unchecked. The issue is outlined here: How do I get the window handle of the desktop?
Your problem results from a fairly widespread confusion over what the
desktop window actually is. The GetDesktopWindow function does
precisely what it's documented to do: it returns a handle to the
desktop window. This, however, is not the same window that contains
the desktop icons.
So I used the answer here: Get handle to desktop / shell window but with replacing or adding methods and p/invoke calls until I had everything necessary because that link only gives method calls and not the dll imports (I may have left some superfluous stuff in here).
static void Main()
{
SendMessage(GetDesktopWindow(DesktopWindow.SysListView32), LVM_ARRANGE, LVA_SNAPTOGRID, 0);
Console.ReadLine();
}
public const int LVM_ARRANGE = 4118;
public const int LVA_SNAPTOGRID = 5;
[DllImport("user32.dll")]
static extern IntPtr GetShellWindow();
[DllImport("user32.dll", CharSet = CharSet.Unicode)]
static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string lclassName, string windowTitle);
[DllImport("User32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr GetDesktopWindow();
[DllImport("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, uint msg, int wParam, int lParam);
[DllImport("user32.dll")]
private static extern bool EnumWindows(EnumWindowsProc enumProc, IntPtr lParam);
public delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam);
[DllImport("user32.dll", CharSet = CharSet.Unicode)]
private static extern int GetWindowText(IntPtr hWnd, StringBuilder strText, int maxCount);
[DllImport("user32.dll", CharSet = CharSet.Unicode)]
private static extern int GetWindowTextLength(IntPtr hWnd);
public enum DesktopWindow
{
ProgMan,
SHELLDLL_DefViewParent,
SHELLDLL_DefView,
SysListView32
}
public static IntPtr GetDesktopWindow(DesktopWindow desktopWindow)
{
IntPtr _ProgMan = GetShellWindow();
IntPtr _SHELLDLL_DefViewParent = _ProgMan;
IntPtr _SHELLDLL_DefView = FindWindowEx(_ProgMan, IntPtr.Zero, "SHELLDLL_DefView", null);
IntPtr _SysListView32 = FindWindowEx(_SHELLDLL_DefView, IntPtr.Zero, "SysListView32", "FolderView");
if (_SHELLDLL_DefView == IntPtr.Zero)
{
EnumWindows((hwnd, lParam) =>
{
if (GetWindowText(hwnd) == "WorkerW")
{
IntPtr child = FindWindowEx(hwnd, IntPtr.Zero, "SHELLDLL_DefView", null);
if (child != IntPtr.Zero)
{
_SHELLDLL_DefViewParent = hwnd;
_SHELLDLL_DefView = child;
_SysListView32 = FindWindowEx(child, IntPtr.Zero, "SysListView32", "FolderView"); ;
return false;
}
}
return true;
}, IntPtr.Zero);
}
switch (desktopWindow)
{
case DesktopWindow.ProgMan:
return _ProgMan;
case DesktopWindow.SHELLDLL_DefViewParent:
return _SHELLDLL_DefViewParent;
case DesktopWindow.SHELLDLL_DefView:
return _SHELLDLL_DefView;
case DesktopWindow.SysListView32:
return _SysListView32;
default:
return IntPtr.Zero;
}
}
public static string GetWindowText(IntPtr hWnd)
{
int size = GetWindowTextLength(hWnd);
if (size > 0)
{
var builder = new StringBuilder(size + 1);
GetWindowText(hWnd, builder, builder.Capacity);
return builder.ToString();
}
return String.Empty;
}

How can I send command "q" to FFMPEG with c#

How Can I send command "q" to process opened FFMPEG with C#? Look my code below:
var p = Process.GetProcessesByName("ffmpeg").FirstOrDefault();
if (p != null)
{
//Here my test
p.StandardInput.Write("q");
}
I took this error below:

You can use the SendMessage call of the user32 api.
[DllImport("user32.dll", EntryPoint = "FindWindowEx")]
public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
[DllImport("User32.dll")]
public static extern int SendMessage(IntPtr hWnd, int uMsg, int wParam, string lParam);
static void Send(string message)
{
Process[] notepads = Process.GetProcessesByName("notepad");
if (notepads.Length == 0)
return;
if (notepads[0] != null)
{
IntPtr child = FindWindowEx(notepads[0].MainWindowHandle, new IntPtr(0), "Edit", null);
SendMessage(child, 0x000C, 0, message);
}
Change it as your needs. im not sure it would work for your situation, but it's always good to try .
Goodluck.

Obtain child window from Process.MainWindowHandle

I want to get a textbox handle from process name. I checked it with Spy++ (it's an exe found in the internet, so nothing special):
now i want to get this TEdit, but it always return NULL. What am I doing wrong?
[DllImport("user32.dll", SetLastError = true)]
private static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string className, string lpszWindow);
private static void Main(string[] args)
{
var processes = Process.GetProcesses();
var proc = Array.Find(processes, x => string.Equals(x.MainWindowTitle, "ExeLock", StringComparison.OrdinalIgnoreCase));
var handle = proc.MainWindowHandle;
//IntPtr edit = FindWindowEx(handle, IntPtr.Zero, "TEdit", null);
IntPtr hwndparent = handle, hwndchild = IntPtr.Zero;
do
{
hwndchild = FindWindowEx(hwndparent, hwndchild, null, null);
} while (hwndchild != IntPtr.Zero);
}

I didn't found it because it creates multiple windows and some of them are hidden (including "main window"). Here is screenshot:
So I just enum every window of a process, find TFormPassDialog and then everything works fine. Here is my code:
class ExeLockFounder
{
const uint WM_SETTEXT = 0x000C;
delegate bool EnumDelegate(IntPtr hWnd, IntPtr lParam);
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
static extern int GetClassName(IntPtr hWnd, StringBuilder lpClassName, int nMaxCount);
[DllImport("user32.dll", SetLastError = true)]
private static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string className, string lpszWindow);
[DllImport("user32.dll")]
static extern bool EnumThreadWindows(int dwThreadId, EnumDelegate lpfn, IntPtr lParam);
[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, [MarshalAs(UnmanagedType.LPStr)] string lParam);
private static IntPtr GetWindowByClassName(IEnumerable<IntPtr> windows, string className)
{
foreach (var window in windows)
{
var sb = new StringBuilder(256);
GetClassName(window, sb, sb.Capacity);
if (sb.ToString() == className)
return window;
}
return IntPtr.Zero;
}
static IEnumerable<IntPtr> EnumerateProcessWindowHandles(Process process)
{
var handles = new List<IntPtr>();
foreach (ProcessThread thread in process.Threads)
EnumThreadWindows(thread.Id, (hWnd, lParam) => { handles.Add(hWnd); return true; }, IntPtr.Zero);
return handles;
}
private readonly IntPtr _editHandle;
public ExeLockFounder()
{
var processes = Process.GetProcessesByName("Setup");
var proc = Array.Find(processes, x => string.Equals(x.MainWindowTitle, "ExeLock", StringComparison.OrdinalIgnoreCase));
var windows = EnumerateProcessWindowHandles(proc);
var hWnd = GetWindowByClassName(windows, "TFormPassDialog");
_editHandle = FindWindowEx(hWnd, IntPtr.Zero, "TEdit", null);
}
public void SendText(string message)
{
SendMessage(_editHandle, WM_SETTEXT, IntPtr.Zero, message);
}
}

Windows 7 left click on clock popup

When left single click on the clock in the taskbar on Windows 7 (maybe Vista too) a popup opens showing calender and clock(s) (thus not the date and time adjust window). How do I open this window myself (preferred in C#)?
I was hoping timedate.cpl would call this, but this opens the date and time adjust window.

To show the clock you need to send the appropriate window message to the tray window. This can be done using the Windows API function SendMessage:
using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Text;
class ShowCalendar
{
private delegate bool EnumChildCallback(IntPtr hwnd,
ref IntPtr lParam);
[DllImport("User32.dll")]
private static extern bool EnumChildWindows(IntPtr hWndParent,
EnumChildCallback lpEnumFunc,
ref IntPtr lParam);
[DllImport("User32.dll")]
private static extern int GetClassName(IntPtr hWnd,
StringBuilder lpClassName,
int nMaxCount);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
private static extern IntPtr SendMessage(IntPtr hWnd,
UInt32 Msg,
IntPtr wParam,
IntPtr lParam);
[DllImport("user32.dll", SetLastError = true)]
private static extern IntPtr FindWindow(string lpClassName,
string lpWindowName);
[DllImport("user32.dll", SetLastError = true)]
private static extern IntPtr FindWindowEx(IntPtr hwndParent,
IntPtr hwndChildAfter,
string lpszClass,
string lpszWindow);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool GetWindowRect(IntPtr hWnd,
out RECT lpRect);
[StructLayout(LayoutKind.Sequential)]
private struct RECT
{
public int Left;
public int Top;
public int Right;
public int Bottom;
}
private static readonly string TrayWndClassName = "Shell_TrayWnd";
private static readonly string TrayNotifyWndClassName = "TrayNotifyWnd";
private static readonly string ClockWndClassName = "TrayClockWClass";
private static readonly uint WM_NCLBUTTONDOWN = 0x00A1;
private static readonly uint HTCAPTION = 2;
private static bool EnumChildProc(IntPtr hwndChild, ref IntPtr lParam)
{
StringBuilder className = new StringBuilder(128);
GetClassName(hwndChild, className, 128);
if (className.ToString() == ClockWndClassName)
{
lParam = hwndChild;
return false;
}
return true;
}
static void Main(string[] args)
{
IntPtr hWndTray = FindWindow(TrayWndClassName, string.Empty);
if (hWndTray == IntPtr.Zero)
{
throw new Win32Exception();
}
IntPtr hWndTrayNotify = FindWindowEx(hWndTray,
IntPtr.Zero,
TrayNotifyWndClassName,
string.Empty);
if (hWndTrayNotify == IntPtr.Zero)
{
throw new Win32Exception();
}
// search clock window
EnumChildCallback cb = new EnumChildCallback(EnumChildProc);
IntPtr hWndClock = IntPtr.Zero;
EnumChildWindows(hWndTray, cb, ref hWndClock);
if (hWndClock == IntPtr.Zero)
{
throw new Win32Exception();
}
// get clock window position
RECT rect;
if (!GetWindowRect(hWndClock, out rect))
{
throw new Win32Exception();
}
// send click, lParam contains window position
IntPtr wParam = new IntPtr(HTCAPTION);
IntPtr lParam = new IntPtr(rect.Top << 16 | rect.Left);
SendMessage(hWndTray, WM_NCLBUTTONDOWN, wParam, lParam);
}
}

How to send text to Notepad in C#/Win32?

I'm trying to use SendMessage to Notepad, so that I can insert written text without making Notepad the active window.
I have done something like this in the past using SendText, but that required giving Notepad focus.
Now, first I'm retrieving the Windows handle:
Process[] processes = Process.GetProcessesByName("notepad");
Console.WriteLine(processes[0].MainWindowHandle.ToString());
I've confirmed it's the right handle for Notepad, the same shown within Windows Task Manager.
[DllImport("User32.dll", EntryPoint = "SendMessage")]
public static extern int SendMessage(int hWnd, int Msg, int wParam, int lParam);
From here, I haven't been able to get SendMessage to work in all my experimentation. Am I going in the wrong direction?

[DllImport("user32.dll", EntryPoint = "FindWindowEx")]
public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
[DllImport("User32.dll")]
public static extern int SendMessage(IntPtr hWnd, int uMsg, int wParam, string lParam);
private void button1_Click(object sender, EventArgs e)
{
Process [] notepads=Process.GetProcessesByName("notepad");
if(notepads.Length==0)return;
if (notepads[0] != null)
{
IntPtr child= FindWindowEx(notepads[0].MainWindowHandle, new IntPtr(0), "Edit", null);
SendMessage(child, 0x000C, 0, textBox1.Text);
}
}
WM_SETTEXT=0x000c

You first have to find the child window where the text is entered. You can do this by finding the child window with the window class "Edit".
Once you have that window handle, use WM_GETTEXT to get the text which is already entered, then modify that text (e.g., add your own), then use WM_SETTEXT to send the modified text back.

using System.Diagnostics;
using System.Runtime.InteropServices;
static class Notepad
{
#region Imports
[DllImport("user32.dll")]
public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
[DllImport("User32.dll")]
private static extern int SendMessage(IntPtr hWnd, int uMsg, int wParam, string lParam);
//this is a constant indicating the window that we want to send a text message
const int WM_SETTEXT = 0X000C;
#endregion
public static void SendText(string text)
{
Process notepad = Process.Start(#"notepad.exe");
System.Threading.Thread.Sleep(50);
IntPtr notepadTextbox = FindWindowEx(notepad.MainWindowHandle, IntPtr.Zero, "Edit", null);
SendMessage(notepadTextbox, WM_SETTEXT, 0, text);
}
}