用C#实现智能设备上的NotifyIcon类

    前几天有网友问.net cf中怎么实现notifyicon，我这才知道原来.net cf并没有提供notifyicon控件。
    于是偶想pc上可以用shell_notifyicon和messagewindow来实现托盘图标，只是不知道.net cf支持不支持这两个东东了。仔细看了一下.net cf中可疑的命名空间，没想到在microsoft.windowsce.forms命名空间里面竟然有一个messagewindow 类，太好了，只剩下一个shell_notifyicon 函数了。接着   在window ce的sdk的帮助文件里，又发现window ce platform api已经包含了shell_notifyicon函数。两大“主料”都齐了，只剩下锅了。
    先看一下messagewindow类，这个类提供了 wndproc 方法，用于处理窗口消息，并公开了可能传递给本机窗口函数的有效窗口句柄。要使用它，派生一个新类，并重写的 wndproc 方法，这样才能截获特定的窗口消息。这里主要用来处理click事件。
        shell_notifyicon的用法如下：

[dllimport("coredll.dll")]
internal static extern int shell_notifyicon(int dwmessage, ref  notifyicondata pnid);

其中，notifyicondata结构如下：

struct notifyicondata
{
    int cbsize;
    intptr hwnd;
    uint uid;
    uint uflags;
    uint ucallbackmessage;
    intptr hicon;
}
     pnid参数的生命需要注意，是按引用传递的，因为shell_notifyicon 需要一个指向 notifyicondata 结构的指针。
    hwnd是用来接收任务栏中图标单击消息的窗口的句柄。
运行示例的时候由于窗体最大化，挡住了任务栏，把窗体最小化之后就能看到托盘图标了。（效果图片竟然贴不上来，改天再贴吧）
该类和示例的下载地址：http://www.cnblogs.com/files/ttinfo/notifyiconcf.rar

下面是notifyicon类的实现，别忘了引用microsoft.windowsce.forms。注意add方法提供了不同的重载形式，具体请参看注释：

using system;
using system.runtime.interopservices;
using system.windows.forms;

namespace notifyclient
{
    /**//// <summary>
    /// 智能设备托盘图标类
    /// </summary>
    public class notifyicon
    {
        //单击事件
        public event system.eventhandler click;

        private mymessagewindow messagewindow;
        private int uid = 5000;
        private system.drawing.icon _icon;
       
        public notifyicon()
        {
            messagewindow = new mymessagewindow(this);
            messagewindow.uid = uid;
        }
        public system.drawing.icon icon
        {
            set
            {
                _icon = value;

            }
        }
     
        ~notifyicon()
        {
            remove();
        }

        /**//// <summary>
        /// 添加托盘图标
        /// </summary>
        /// <param name="hicon">icon文件的有效句柄</param>
        public void add(intptr hicon)
        {
            notifymessage(messagewindow.hwnd, nim_add, (uint)uid, hicon);
        }
        /**//// <summary>
        /// 添加托盘图标
        /// </summary>
        /// <param name="iconres">编译之后的资源文件中的icon资源名称，如“#201547”</param>
        public void add(string iconres)
        {
            intptr hicon = loadicon(getmodulehandle(null), iconres);
            notifymessage(messagewindow.hwnd, nim_add, (uint)uid, hicon);
        }
        /**//// <summary>
        /// 添加托盘图标
        /// </summary>
        /// <param name="icon">icon文件</param>
        public void add(system.drawing.icon icon)
        {
            notifymessage(messagewindow.hwnd, nim_add, (uint)uid, icon.handle);
        }
        /**//// <summary>
        /// 添加托盘图标；icon为属性中的icon
        /// </summary>
        public void add()
        {
            if (_icon != null)
            {
                notifymessage(messagewindow.hwnd, nim_add, (uint)uid, _icon.handle);
            }
        }
        public void remove()
        {

            notifymessage(messagewindow.hwnd, nim_delete, (uint)uid, intptr.zero);
        }

        public void modify(intptr hicon)
        {

            notifymessage(messagewindow.hwnd, nim_modify, (uint)uid, hicon);

        }

        private void notifymessage(intptr hwnd, int dwmessage, uint uid, intptr hicon)
        {
            notifyicondata notdata = new notifyicondata();

            notdata.cbsize = 152;
            notdata.hicon = hicon;
            notdata.hwnd = hwnd;
            notdata.ucallbackmessage = wm_notify_tray;
            notdata.uflags = nif_message | nif_icon;
            notdata.uid = uid;

            int ret = shell_notifyicon(dwmessage, ref notdata);
        }

        api#region api
        //定义消息常量
        const int nif_message = 0x00000001;
        const int nif_icon = 0x00000002;
        internal const int wm_lbuttondown = 0x0201;   

        internal const int nim_add = 0x00000000;
        internal const int nim_modify = 0x00000001;
        internal const int nim_delete = 0x00000002;

        //自定义消息
        internal const int wm_notify_tray = 0x0400 + 2001;

        internal struct notifyicondata
        {
            internal int cbsize;
            internal intptr hwnd;
            internal uint uid;
            internal uint uflags;
            internal uint ucallbackmessage;
            internal intptr hicon;           
        }

        [dllimport("coredll.dll")]
        internal static extern int shell_notifyicon(
            int dwmessage, ref notifyicondata pnid);

        [dllimport("coredll.dll")]
        internal static extern int setforegroundwindow(intptr hwnd);

        [dllimport("coredll.dll")]
        internal static extern int showwindow(
            intptr hwnd,
            int ncmdshow);

        [dllimport("coredll.dll")]
        internal static extern intptr getfocus();

        [dllimport("coredll.dll")]
        internal static extern intptr loadicon(intptr hinst, string iconname);

        [dllimport("coredll.dll")]
        internal static extern intptr getmodulehandle(string lpmodulename);

        #endregion

        messagewindow#region messagewindow

        internal class mymessagewindow : microsoft.windowsce.forms.messagewindow
        {
           
            private int _uid = 0;
            private notifyicon notifyicon;

          
            public mymessagewindow(notifyicon noticon)
            {
                notifyicon = noticon;
            }

            public int uid
            {
                set
                {
                    _uid = value;

                }
            }

            protected override void wndproc(ref microsoft.windowsce.forms.message msg)
            {

                if (msg.msg == wm_notify_tray)
                {
                    if ((int)msg.lparam == wm_lbuttondown)
                    {
                        if ((int)msg.wparam == _uid)
                        {
                           
                            if (notifyicon.click != null)
                                notifyicon.click(notifyicon, null);

                        }
                    }
                }

            }
        }
        #endregion

    }
}