怎样捕获鼠标滚轮的向上和向下消息

Question

怎样捕获鼠标滚轮的向上和向下消息

Answer 1

OnMouseWheel()
两个消息分别是：
WM_LBUTTONDOWN 
WM_LBUTTONUP

Answer 2

        [DllImport("user32.dll")]
        public static extern bool ReleaseCapture();
        [DllImport("user32.dll")]
        public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int   
        lParam);//API函数

Answer 3

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.Reflection;namespace Hook
{
    class Hook
    {
        [StructLayout(LayoutKind.Sequential)]
        private class POINT
        {
            public int x;
            public int y;
        }        [StructLayout(LayoutKind.Sequential)]
        private class MouseHookStruct
        {
            public POINT pt;
            public int hwnd;
            public int wHitTestCode;
            public int dwExtraInfo;
        }        [StructLayout(LayoutKind.Sequential)]
        private class MouseLLHookStruct
        {
            public POINT pt;
            public int mouseData;
            public int flags;
            public int time;
            public int dwExtraInfo;
        }        
        [DllImport("kernel32")]
        public static extern int GetCurrentThreadId();        [DllImport("user32.dll")]
        private static extern int SetWindowsHookEx(
            int idHook,
            HookProc lpfn,
            IntPtr hMod,
            int dwThreadId);        [DllImport("user32.dll")]
        private static extern int UnhookWindowsHookEx(int idHook);        [DllImport("user32.dll")]
        private static extern int CallNextHookEx(
            int idHook,
            int nCode,
            int wParam,
            IntPtr lParam);        private delegate int HookProc(int nCode, int wParam, IntPtr lParam);
        private const int WH_MOUSE = 7;
        private const int WM_MOUSEWHEEL = 0x020A;
        private int hMouseHook = 0;
        private static HookProc KeyboardProcedure;
       
        private int MouseHookProc(int nCode, int wParam, IntPtr lParam)
        {
            if (nCode >= 0)
            {
                switch (wParam)
                {
                    case WM_MOUSEWHEEL:
                        {
                            MouseLLHookStruct mouseHookStruct = (MouseLLHookStruct)Marshal.PtrToStructure(lParam, typeof(MouseLLHookStruct));                            //mouseHookStruct.mouseData　就是Delta
                            //下面是MSDN中的解释
                            //如是消息是WM_MOUSEWHELL　 mouseData中的高位（高16位）就是Delta
                            //鼠标轮将轮和鼠标按钮的功能结合在了一起。鼠标轮有一些相互分开的、间距均匀的凹口。当您旋转鼠标轮时，每碰到一个凹口就会发送一个鼠标轮消息。
                            //Windows 常数 WHEEL_DELTA 定义了一个鼠标轮凹口，即一个制动器，值为120。
                            //正值指示鼠标轮向前（远离用户的方向）转动；负值指示鼠标轮向后（朝着用户的方向）转动。
                            //当前，120 是一个制动器的标准值。如果使用分辨率更高的鼠标，则 WHEEL_DATA 定义的值可能会更小。
                            //大多数应用程序都应检查值为正还是为负，而不是值聚合总数。                                                        
                            break;
                        }
                    
                }
 
            }
            return CallNextHookEx(hMouseHook, nCode, wParam, lParam);
        }              public bool StartMouseHook()
        {
            MouseHookProcedure = new HookProc(MouseHookProc);            hMouseHook = SetWindowsHookEx(WH_MOUSE,
                MouseHookProcedure,
                IntPtr.Zero,
                GetCurrentThreadId());            if (hMouseHook == 0)
                return false;
            else
                return true;        }
       
        public bool StopMouseHook()
        {
            int retMouse = UnhookWindowsHookEx(hMouseHook);
            if (retMouse == 0)
                return true;
            else
                return false;
        }
    }
}

Answer 4

一般不会向上滚轮和向下滚轮两个事件的，除非自己设相应的MESSAGE，重载windows procedure。大部分控件都带MouseWheel事件的吧，相应的事件参数类型是MouseEventArgs。
MouseEventArgs有个delta属性，在这个事件中表示滚轮滚动的度数，若为正则滚轮的方向为向前推（远离你，即你说的“向上”），否则为向后拨（靠近你，即你说的“向下”）。如果你要重载windows procedure的话，相应的Message为WM_MOUSEWHEEL（据我所知没有直接分出滚轮滚动方向的两个事件），这个Message的wParam的高16位与上述MouseEventArgs的delta意义类似，正负方向相同。详见http://msdn.microsoft.com/en-us/library/ms645617(v=VS.85).aspx