{
public event KeyEventHandler KeyDownEvent;
public event KeyPressEventHandler KeyPressEvent;
public event KeyEventHandler KeyUpEvent;
public delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);
static int hKeyboardHook = 0; //声明键盘钩子处理的初始值
//值在Microsoft SDK的Winuser.h里查询
public const int WH_KEYBOARD_LL = 13; //线程键盘钩子监听键盘消息设为2，全局键盘监听鼠标消息设为13
HookProc KeyboardHookProcedure; //声明KeyboardHookProcedure作为HookProc类型
//键盘结构
[StructLayout(LayoutKind.Sequential)]
public class KeyboardHookStruct
{
public int vkCode; //定一个虚拟键码。该代码必须有一个价值的范围1至254
public int scanCode; // 指定的硬件扫描码的关键
public int flags; // 键标志
public int time; // 指定的时间戳记的这个讯息
public int dwExtraInfo; // 指定额外信息相关的信息
}
//使用此功能，安装了一个钩子
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);
//调用此函数卸载钩子
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern bool UnhookWindowsHookEx(int idHook);
//使用此功能，通过信息钩子继续下一个钩子
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam);
// 取得当前线程编号（线程钩子需要用到）
[DllImport("kernel32.dll")]
static extern int GetCurrentThreadId();
//使用WINDOWS API函数代替获取当前实例的函数,防止钩子失效
[DllImport("kernel32.dll")]
public static extern IntPtr GetModuleHandle(string name);
public void Start()
{
// 安装键盘钩子
if (hKeyboardHook == 0)
{
KeyboardHookProcedure = new HookProc(KeyboardHookProc);
hKeyboardHook = SetWindowsHookEx(WH_KEYBOARD_LL, KeyboardHookProcedure, GetModuleHandle(System.Diagnostics.Process.GetCurrentProcess().MainModule.ModuleName), 0);
//hKeyboardHook = SetWindowsHookEx(WH_KEYBOARD_LL, KeyboardHookProcedure, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);
//************************************
//键盘线程钩子
//SetWindowsHookEx( 2,KeyboardHookProcedure, IntPtr.Zero, GetCurrentThreadId());//指定要监听的线程idGetCurrentThreadId(),
//键盘全局钩子,需要引用空间(using System.Reflection;)
//SetWindowsHookEx( 13,MouseHookProcedure,Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]),0);
//
//关于SetWindowsHookEx (int idHook, HookProc lpfn, IntPtr hInstance, int threadId)函数将钩子加入到钩子链表中，说明一下四个参数：
//idHook 钩子类型，即确定钩子监听何种消息，上面的代码中设为2，即监听键盘消息并且是线程钩子，如果是全局钩子监听键盘消息应设为13，
//线程钩子监听鼠标消息设为7，全局钩子监听鼠标消息设为14。lpfn 钩子子程的地址指针。如果dwThreadId参数为0 或是一个由别的进程创建的
//线程的标识，lpfn必须指向DLL中的钩子子程。 除此以外，lpfn可以指向当前进程的一段钩子子程代码。钩子函数的入口地址，当钩子钩到任何
//消息后便调用这个函数。hInstance应用程序实例的句柄。标识包含lpfn所指的子程的DLL。如果threadId 标识当前进程创建的一个线程，而且子
//程代码位于当前进程，hInstance必须为NULL。可以很简单的设定其为本应用程序的实例句柄。threaded 与安装的钩子子程相关联的线程的标识符
//如果为0，钩子子程与所有的线程关联，即为全局钩子
//************************************
//如果SetWindowsHookEx失败
if (hKeyboardHook == 0)
{
Stop();
throw new Exception("安装键盘钩子失败");
}
}
}
public void Stop()
{
bool retKeyboard = true;
if (hKeyboardHook != 0)
{
retKeyboard = UnhookWindowsHookEx(hKeyboardHook);
hKeyboardHook = 0;
}
if (!(retKeyboard)) throw new Exception("卸载钩子失败！");
}
//ToAscii职能的转换指定的虚拟键码和键盘状态的相应字符或字符
[DllImport("user32")]
public static extern int ToAscii(int uVirtKey, //[in] 指定虚拟关键代码进行翻译。
int uScanCode, // [in] 指定的硬件扫描码的关键须翻译成英文。高阶位的这个值设定的关键，如果是（不压）
byte[] lpbKeyState, // [in] 指针，以256字节数组，包含当前键盘的状态。每个元素（字节）的数组包含状态的一个关键。如果高阶位的字节是一套，关键是下跌（按下）。在低比特，如果设置表明，关键是对切换。在此功能，只有肘位的CAPS LOCK键是相关的。在切换状态的NUM个锁和滚动锁定键被忽略。
byte[] lpwTransKey, // [out] 指针的缓冲区收到翻译字符或字符。
int fuState); // [in] Specifies whether a menu is active. This parameter must be 1 if a menu is active, or 0 otherwise.
//获取按键的状态
[DllImport("user32")]
public static extern int GetKeyboardState(byte[] pbKeyState);
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
private static extern short GetKeyState(int vKey);
private const int WM_KEYDOWN = 0x100;//KEYDOWN
private const int WM_KEYUP = 0x101;//KEYUP
private const int WM_SYSKEYDOWN = 0x104;//SYSKEYDOWN
private const int WM_SYSKEYUP = 0x105;//SYSKEYUP
private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
{
// 侦听键盘事件
if ((nCode >= 0) && (KeyDownEvent != null || KeyUpEvent != null || KeyPressEvent != null))
{
KeyboardHookStruct MyKeyboardHookStruct = (KeyboardHookStruct)Marshal.PtrToStructure(lParam, typeof(KeyboardHookStruct));
// raise KeyDown
if (KeyDownEvent != null && (wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN))
{
Keys keyData = (Keys)MyKeyboardHookStruct.vkCode;
KeyEventArgs e = new KeyEventArgs(keyData);
KeyDownEvent(this, e);
}
//键盘按下
if (KeyPressEvent != null && wParam == WM_KEYDOWN)
{
byte[] keyState = new byte[256];
GetKeyboardState(keyState);
byte[] inBuffer = new byte[2];
if (ToAscii(MyKeyboardHookStruct.vkCode, MyKeyboardHookStruct.scanCode, keyState, inBuffer, MyKeyboardHookStruct.flags) == 1)
{
KeyPressEventArgs e = new KeyPressEventArgs((char)inBuffer[0]);
KeyPressEvent(this, e);
}
}
// 键盘抬起
if (KeyUpEvent != null && (wParam == WM_KEYUP || wParam == WM_SYSKEYUP))
{
Keys keyData = (Keys)MyKeyboardHookStruct.vkCode;
KeyEventArgs e = new KeyEventArgs(keyData);
KeyUpEvent(this, e);
}
}
//如果返回1，则结束消息，这个消息到此为止，不再传递。
//如果返回0或调用CallNextHookEx函数则消息出了这个钩子继续往下传递，也就是传给消息真正的接受者
return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
}
~KeyboardHook()
{
Stop();
}
}
KeyboardHook BarCode = new KeyboardHook();
static void Main(){
BarCode.KeyDownEvent += BarCode_KeyDownEvent;
}
private void BarCode_KeyDownEvent(object sender, System.Windows.Forms.KeyEventArgs e)
{
string temp = string.Empty;
DateTime nowTime = DateTime.Now;
//string temp = string.Empty;
//判断是不是数字的键盘值
if ((e.KeyData >= Keys.D0 && e.KeyData <= Keys.D9) || (e.KeyData >= Keys.NumPad0 && e.KeyData <= Keys.NumPad9))
{
temp = (e.KeyData.ToString()).Last().ToString();
//Content.Text = (e.KeyData.ToString()).Last().ToString();
}
else
{
temp = e.KeyData.ToString();
}
if ((nowTime - previewTime).Milliseconds < 20)//通过判断键盘输入的间隔来确定是扫描枪还是通过键盘输入的
{
if (e.KeyValue == (int)Keys.Return && inputKey.Length > 2)
{
previewTime = DateTime.Now;
return;
}
inputKey.Append(temp);
//Console.WriteLine(inputKey);
string tempContent = inputKey.ToString();
}
else
{
inputKey = new StringBuilder(temp);
}
previewTime = DateTime.Now;
}