重複の可能性:
globalKeyboardHook で CallbackOnCollectedDelegate が検出されました
メイン (および唯一の) フォームを非表示から呼び出すと、例外が発生します。再び見えるようにするキーを監視するためのキーフックがあります。ただし、問題は、キーが押されてフォームが読み込まれると、この例外が発生することです
タイプ 'MyProgram!Utilities.globalKeyboardHook+keyboardHookProc::Invoke' のガベージ コレクション デリゲートでコールバックが行われました。これにより、アプリケーションのクラッシュ、破損、データ損失が発生する可能性があります。デリゲートをアンマネージ コードに渡す場合、デリゲートが呼び出されないことが保証されるまで、マネージ アプリケーションによって保持される必要があります。
キーフックを扱ったのはこれが初めてだったり、別のフォームを使用せずにフォームを元に戻したりしたので、ここで少し途方に暮れています。何を狙っているのかよくわかりません。プログラムがフォームをシャットダウンしようとするのを防ぐために、フォームの不透明度を 0 にする必要がありますか?
パブリック部分クラス Form1 : フォーム {
//Variables
globalKeyboardHook gkh = new globalKeyboardHook();
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
gkh.HookedKeys.Add(Keys.A);
gkh.HookedKeys.Add(Keys.Left);
gkh.KeyDown += new KeyEventHandler(gkh_KeyDown);
gkh.KeyUp += new KeyEventHandler(gkh_KeyUp);
}
private void OpacityBar_ValueChanged(object sender, EventArgs e)
{
//Do stuff
private void VisibleTSMI_Click(object sender, EventArgs e)
{
//Do more un-important stuff
}
void gkh_KeyUp(object sender, KeyEventArgs e)
{
if (KeyDown == true)
{
this.Visible = true;
}
e.Handled = true;
}
void gkh_KeyDown(object sender, KeyEventArgs e)
{
KeyDown = true;
e.Handled = true;
}
class globalKeyboardHook
{
#region Constant, Structure and Delegate Definitions
/// <summary>
/// defines the callback type for the hook
/// </summary>
public delegate int keyboardHookProc(int code, int wParam, ref keyboardHookStruct lParam);
public struct keyboardHookStruct
{
public int vkCode;
public int scanCode;
public int flags;
public int time;
public int dwExtraInfo;
}
const int WH_KEYBOARD_LL = 13;
const int WM_KEYDOWN = 0x100;
const int WM_KEYUP = 0x101;
const int WM_SYSKEYDOWN = 0x104;
const int WM_SYSKEYUP = 0x105;
#endregion
#region Instance Variables
/// <summary>
/// The collections of keys to watch for
/// </summary>
public List<Keys> HookedKeys = new List<Keys>();
/// <summary>
/// Handle to the hook, need this to unhook and call the next hook
/// </summary>
IntPtr hhook = IntPtr.Zero;
#endregion
#region Events
/// <summary>
/// Occurs when one of the hooked keys is pressed
/// </summary>
public event KeyEventHandler KeyDown;
/// <summary>
/// Occurs when one of the hooked keys is released
/// </summary>
public event KeyEventHandler KeyUp;
#endregion
#region Constructors and Destructors
/// <summary>
/// Initializes a new instance of the <see cref="globalKeyboardHook"/> class and installs the keyboard hook.
/// </summary>
public globalKeyboardHook()
{
hook();
}
/// <summary>
/// Releases unmanaged resources and performs other cleanup operations before the
/// <see cref="globalKeyboardHook"/> is reclaimed by garbage collection and uninstalls the keyboard hook.
/// </summary>
~globalKeyboardHook()
{
unhook();
}
#endregion
#region Public Methods
/// <summary>
/// Installs the global hook
/// </summary>
public void hook()
{
IntPtr hInstance = LoadLibrary("User32");
hhook = SetWindowsHookEx(WH_KEYBOARD_LL, hookProc, hInstance, 0);
}
/// <summary>
/// Uninstalls the global hook
/// </summary>
public void unhook()
{
UnhookWindowsHookEx(hhook);
}
/// <summary>
/// The callback for the keyboard hook
/// </summary>
/// <param name="code">The hook code, if it isn't >= 0, the function shouldn't do anyting</param>
/// <param name="wParam">The event type</param>
/// <param name="lParam">The keyhook event information</param>
/// <returns></returns>
public int hookProc(int code, int wParam, ref keyboardHookStruct lParam)
{
if (code >= 0)
{
Keys key = (Keys)lParam.vkCode;
if (HookedKeys.Contains(key))
{
KeyEventArgs kea = new KeyEventArgs(key);
if ((wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN) && (KeyDown != null))
{
KeyDown(this, kea);
}
else if ((wParam == WM_KEYUP || wParam == WM_SYSKEYUP) && (KeyUp != null))
{
KeyUp(this, kea);
}
if (kea.Handled)
return 1;
}
}
return CallNextHookEx(hhook, code, wParam, ref lParam);
}
#endregion
#region DLL imports
/// <summary>
/// Sets the windows hook, do the desired event, one of hInstance or threadId must be non-null
/// </summary>
/// <param name="idHook">The id of the event you want to hook</param>
/// <param name="callback">The callback.</param>
/// <param name="hInstance">The handle you want to attach the event to, can be null</param>
/// <param name="threadId">The thread you want to attach the event to, can be null</param>
/// <returns>a handle to the desired hook</returns>
[DllImport("user32.dll")]
static extern IntPtr SetWindowsHookEx(int idHook, keyboardHookProc callback, IntPtr hInstance, uint threadId);
/// <summary>
/// Unhooks the windows hook.
/// </summary>
/// <param name="hInstance">The hook handle that was returned from SetWindowsHookEx</param>
/// <returns>True if successful, false otherwise</returns>
[DllImport("user32.dll")]
static extern bool UnhookWindowsHookEx(IntPtr hInstance);
/// <summary>
/// Calls the next hook.
/// </summary>
/// <param name="idHook">The hook id</param>
/// <param name="nCode">The hook code</param>
/// <param name="wParam">The wparam.</param>
/// <param name="lParam">The lparam.</param>
/// <returns></returns>
[DllImport("user32.dll")]
static extern int CallNextHookEx(IntPtr idHook, int nCode, int wParam, ref keyboardHookStruct lParam);
/// <summary>
/// Loads the library.
/// </summary>
/// <param name="lpFileName">Name of the library</param>
/// <returns>A handle to the library</returns>
[DllImport("kernel32.dll")]
static extern IntPtr LoadLibrary(string lpFileName);
#endregion
}
}
ご注意ください; Utilities 名前空間は、Form1 コードに統合した後にスクラッチしたため、これ以上ありません。