我在我的XNA项目中使用了一个Keyboard钩子（任何使用XNA的人都知道内置键盘类对于“文本框”样式输入是多么无用。
在引入表单之前，它适用于XNA项目。如果我尝试在项目中实现任何表单，无论是自定义表单，还是只是OpenFileDialog，表单文本框内的任何按键都会加倍，这使得输入几乎不可能。
有谁知道如何阻止邮件两次到达表单？也许是在我得到消息时丢弃消息？也许有更好的解决方案？或许它只是一些无法完成的事情。
感谢任何帮助。
修改
下面是我正在使用的键盘挂钩代码，对于那些寻找XNA键盘挂钩的人来说可能很熟悉，因为它似乎在我找到它的地方突然出现。
using System;
using System.Runtime.InteropServices;
using System.Windows.Forms; // This class exposes WinForms-style key events.
namespace FatLib.Controls
{
class KeyboardHookInput : IDisposable
{
private string _buffer = "";
private bool _backSpace = false;
private bool _enterKey = false; // I added this to the original code
public string Buffer
{
get { return _buffer; }
}
public bool BackSpace
{
get
{
return _backSpace;
}
}
public bool EnterKey
{
get
{
return _enterKey;
}
}
public void Reset()
{
_buffer = "";
_backSpace = false;
_enterKey = false;
}
public enum HookId
{
// Types of hook that can be installed using the SetWindwsHookEx function.
WH_CALLWNDPROC = 4,
WH_CALLWNDPROCRET = 12,
WH_CBT = 5,
WH_DEBUG = 9,
WH_FOREGROUNDIDLE = 11,
WH_GETMESSAGE = 3,
WH_HARDWARE = 8,
WH_JOURNALPLAYBACK = 1,
WH_JOURNALRECORD = 0,
WH_KEYBOARD = 2,
WH_KEYBOARD_LL = 13,
WH_MAX = 11,
WH_MAXHOOK = WH_MAX,
WH_MIN = -1,
WH_MINHOOK = WH_MIN,
WH_MOUSE_LL = 14,
WH_MSGFILTER = -1,
WH_SHELL = 10,
WH_SYSMSGFILTER = 6,
};
public enum WindowMessage
{
// Window message types.
WM_KEYDOWN = 0x100,
WM_KEYUP = 0x101,
WM_CHAR = 0x102,
};
// A delegate used to create a hook callback.
public delegate int GetMsgProc(int nCode, int wParam, ref Message msg);
/// <summary>
/// Install an application-defined hook procedure into a hook chain.
/// </summary>
/// <param name="idHook">Specifies the type of hook procedure to be installed.</param>
/// <param name="lpfn">Pointer to the hook procedure.</param>
/// <param name="hmod">Handle to the DLL containing the hook procedure pointed to by the lpfn parameter.</param>
/// <param name="dwThreadId">Specifies the identifier of the thread with which the hook procedure is to be associated.</param>
/// <returns>If the function succeeds, the return value is the handle to the hook procedure. Otherwise returns 0.</returns>
[DllImport("user32.dll", EntryPoint = "SetWindowsHookExA")]
public static extern IntPtr SetWindowsHookEx(HookId idHook, GetMsgProc lpfn, IntPtr hmod, int dwThreadId);
/// <summary>
/// Removes a hook procedure installed in a hook chain by the SetWindowsHookEx function.
/// </summary>
/// <param name="hHook">Handle to the hook to be removed. This parameter is a hook handle obtained by a previous call to SetWindowsHookEx.</param>
/// <returns>If the function fails, the return value is zero. To get extended error information, call GetLastError.</returns>
[DllImport("user32.dll")]
public static extern int UnhookWindowsHookEx(IntPtr hHook);
/// <summary>
/// Passes the hook information to the next hook procedure in the current hook chain.
/// </summary>
/// <param name="hHook">Ignored.</param>
/// <param name="ncode">Specifies the hook code passed to the current hook procedure.</param>
/// <param name="wParam">Specifies the wParam value passed to the current hook procedure.</param>
/// <param name="lParam">Specifies the lParam value passed to the current hook procedure.</param>
/// <returns>This value is returned by the next hook procedure in the chain.</returns>
[DllImport("user32.dll")]
public static extern int CallNextHookEx(int hHook, int ncode, int wParam, ref Message lParam);
/// <summary>
/// Translates virtual-key messages into character messages.
/// </summary>
/// <param name="lpMsg">Pointer to an Message structure that contains message information retrieved from the calling thread's message queue.</param>
/// <returns>If the message is translated (that is, a character message is posted to the thread's message queue), the return value is true.</returns>
[DllImport("user32.dll")]
public static extern bool TranslateMessage(ref Message lpMsg);
/// <summary>
/// Retrieves the thread identifier of the calling thread.
/// </summary>
/// <returns>The thread identifier of the calling thread.</returns>
[DllImport("kernel32.dll")]
public static extern int GetCurrentThreadId();
// Handle for the created hook.
private readonly IntPtr HookHandle;
private readonly GetMsgProc ProcessMessagesCallback;
public KeyboardHookInput()
{
// Create the delegate callback:
this.ProcessMessagesCallback = new GetMsgProc(ProcessMessages);
// Create the keyboard hook:
this.HookHandle = SetWindowsHookEx(HookId.WH_KEYBOARD, this.ProcessMessagesCallback, IntPtr.Zero, GetCurrentThreadId());
}
public void Dispose()
{
// Remove the hook.
if (HookHandle != IntPtr.Zero) UnhookWindowsHookEx(HookHandle);
}
// comments found in this region are all from the original author: Darg.
private int ProcessMessages(int nCode, int wParam, ref Message msg)
{
// Check if we must process this message (and whether it has been retrieved via GetMessage):
if (nCode == 0 && wParam == 1)
{
// We need character input, so use TranslateMessage to generate WM_CHAR messages.
TranslateMessage(ref msg);
// If it's one of the keyboard-related messages, raise an event for it:
switch ((WindowMessage)msg.Msg)
{
case WindowMessage.WM_CHAR:
this.OnKeyPress(new KeyPressEventArgs((char)msg.WParam));
break;
case WindowMessage.WM_KEYDOWN:
this.OnKeyDown(new KeyEventArgs((Keys)msg.WParam));
break;
case WindowMessage.WM_KEYUP:
this.OnKeyUp(new KeyEventArgs((Keys)msg.WParam));
break;
}
}
// Call next hook in chain:
return CallNextHookEx(0, nCode, wParam, ref msg);
}
public event KeyEventHandler KeyUp;
protected virtual void OnKeyUp(KeyEventArgs e)
{
if (KeyUp != null) KeyUp(this, e);
}
public event KeyEventHandler KeyDown;
protected virtual void OnKeyDown(KeyEventArgs e)
{
if (KeyDown != null) KeyDown(this, e);
}
public event KeyPressEventHandler KeyPress;
protected virtual void OnKeyPress(KeyPressEventArgs e)
{
if (KeyPress != null) KeyPress(this, e);
if (e.KeyChar.GetHashCode().ToString() == "524296")
{
_backSpace = true;
}
else if (e.KeyChar == (char)Keys.Enter)
{
_enterKey = true;
}
else
{
_buffer += e.KeyChar;
}
}
}
}
答案 0 :(得分：3)
由于XNA中必须有一个表单（GraphicsDevice需要它），您将有2个选项，具体取决于您的库用户是否使用XNA创建表单winforms项目用于渲染），或者是否由于创建普通XNA游戏而创建表单。
在winforms案例中，您可以处理关键事件，完成工作。
在标准的XNA游戏案例中，您可以让用户传递图形设备创建的窗口的句柄，然后在调用OnKey...方法之前，检查窗口是否有焦点。
在这两种情况下你都可以使用第二个选项来简化它。库的用户将传入窗口的句柄，以在KeyboardHookInput的构造函数中接收/缓冲键按下。然后你会先检查窗口是否有焦点（见这里：How can I tell if a Window has focus? (Win32 API)）。
答案 1 :(得分：3)
Windows Hook是获取所有按键的一种非常讨厌的方式，应该是绝对的最后手段。
尝试在您的应用程序中安装Message Filter，它可以监视发送到您的应用程序的所有键盘消息（WM_KEYPRESS，KEYUP，KEYDOWN等），而不会干扰其他应用程序。如果您愿意，过滤器还允许您停止任何到达应用程序中任何表单的邮件。