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POCapturing Alt+PrintScreen hot key and clipboard contents
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  1. POCapturing Alt+PrintScreen hot key and clipboard contents
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    copied!<p>I setup catching hotkey on alt+printscreen. It catches perfectly but there is nothing in the buffer - no image. How can I get the image from Clipboard.GetImage() after catching hotkey?</p> <p>Here is the the code.</p> <pre><code>using System; using System.Runtime.InteropServices; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; namespace Magic_Screenshot { public enum ModifierKey : uint { MOD_NULL = 0x0000, MOD_ALT = 0x0001, MOD_CONTROL = 0x0002, MOD_SHIFT = 0x0004, MOD_WIN = 0x0008, } public enum HotKey { PrintScreen, ALT_PrintScreen, CONTROL_PrintScreen } public class HotKeyHelper : IMessageFilter { const string MSG_REGISTERED = "Горячие клавиши уже зарегистрированы, вызовите UnRegister для отмены регистрации."; const string MSG_UNREGISTERED = "Горячие клавиши не зарегистрированы, вызовите Register для регистрации."; //Делаем из нашего класса singleton public HotKeyHelper() { } //public static readonly HotKeyHelper Instance = new HotKeyHelper(); public bool isRegistered; ushort atom; //ushort atom1; ModifierKey modifiers; Keys keyCode; public void Register(ModifierKey modifiers, Keys keyCode) { //Эти значения нам будут нужны в PreFilterMessage this.modifiers = modifiers; this.keyCode = keyCode; //Не выполнена ли уже регистрация? //if (isRegistered) // throw new InvalidOperationException(MSG_REGISTERED); //Сохраняем atom, для последующей отмены регистрации atom = GlobalAddAtom(Guid.NewGuid().ToString()); //atom1 = GlobalAddAtom(Guid.NewGuid().ToString()); if (atom == 0) ThrowWin32Exception(); if (!RegisterHotKey(IntPtr.Zero, atom, modifiers, keyCode)) ThrowWin32Exception(); //if (!RegisterHotKey(IntPtr.Zero, atom1, ModifierKey.MOD_CONTROL, Keys.PrintScreen)) // ThrowWin32Exception(); //Добавляем себя в цепочку фильтров сообщений Application.AddMessageFilter(this); isRegistered = true; } public void UnRegister() { //Не отменена ли уже регистрация? if (!isRegistered) throw new InvalidOperationException(MSG_UNREGISTERED); if (!UnregisterHotKey(IntPtr.Zero, atom)) ThrowWin32Exception(); GlobalDeleteAtom(atom); //Удаляем себя из цепочки фильтров сообщений Application.RemoveMessageFilter(this); isRegistered = false; } //Генерирует Win32Exception в ответ на неудачный вызов импортируемой Win32 функции void ThrowWin32Exception() { throw new Win32Exception(Marshal.GetLastWin32Error()); } //Событие, инициируемое при обнаружении нажатия HotKeys public event HotKeyHelperDelegate HotKeyPressed; public bool PreFilterMessage(ref Message m) { //Проверка на сообщение WM_HOTKEY if (m.Msg == WM_HOTKEY &amp;&amp; //Проверка на окно m.HWnd == IntPtr.Zero &amp;&amp; //Проверка virtual key code m.LParam.ToInt32() &gt;&gt; 16 == (int)keyCode &amp;&amp; //Проверка кнопок модификаторов (m.LParam.ToInt32() &amp; 0x0000FFFF) == (int)modifiers &amp;&amp; //Проверка на наличие подписчиков сообщения HotKeyPressed != null) { if ((m.LParam.ToInt32() &amp; 0x0000FFFF) == (int)ModifierKey.MOD_CONTROL &amp;&amp; (m.LParam.ToInt32() &gt;&gt; 16 == (int)Keys.PrintScreen)) { HotKeyPressed(this, EventArgs.Empty, HotKey.CONTROL_PrintScreen); } else if ((m.LParam.ToInt32() &amp; 0x0000FFFF) == (int)ModifierKey.MOD_ALT &amp;&amp; (m.LParam.ToInt32() &gt;&gt; 16 == (int)Keys.PrintScreen)) { HotKeyPressed(this, EventArgs.Empty, HotKey.ALT_PrintScreen); } else if (m.LParam.ToInt32() &gt;&gt; 16 == (int)Keys.PrintScreen) { HotKeyPressed(this, EventArgs.Empty, HotKey.PrintScreen); } } return false; } //Необходимые Win32 константы и функции const string USER32_DLL = "User32.dll"; const string KERNEL32_DLL = "Kernel32.dll"; const int WM_HOTKEY = 0x0312; [DllImport(USER32_DLL, SetLastError = true)] static extern bool RegisterHotKey(IntPtr hWnd, int id, ModifierKey fsModifiers, Keys vk); [DllImport(USER32_DLL, SetLastError = true)] static extern bool UnregisterHotKey(IntPtr hWnd, int id); [DllImport(KERNEL32_DLL, SetLastError = true)] static extern ushort GlobalAddAtom(string lpString); [DllImport(KERNEL32_DLL)] static extern ushort GlobalDeleteAtom(ushort nAtom); } } </code></pre> <p>Where is the bug?</p>
 

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