获取应用程序的 NotifyIcon 矩形？

Question

我想知道我的NotifyIcon 在系统托盘中的位置（在执行任何点击之前）。

在this other question@Hans Passant 发表评论说NO，这是不可能的，但我认为几乎所有可以由操作系统内部完成的事情也可以由开发人员复制，如果我不对，那么为什么 SO 可以获取 NotifyIcon 位置以在其上显示弹出窗口？。

在上面的同一个问题中，有一个 C# 示例说明了如何定位系统托盘矩形，我想知道这是否是一个开始。

这个任务能实现吗？

如果是，那怎么办？

如果不能，为什么操作系统可以？以何种方式限制我们无法重现相同的事物？

Answer 1

你需要这些声明：

    public const Int32 WM_MYMESSAGE = 0x8000; //WM_APP
    public const Int32 NOTIFYICON_VERSION_4 = 0x4;

    //messages
    public const Int32 WM_CONTEXTMENU = 0x7B;
    public const Int32 NIN_BALLOONHIDE = 0x403;
    public const Int32 NIN_BALLOONSHOW = 0x402;
    public const Int32 NIN_BALLOONTIMEOUT = 0x404;
    public const Int32 NIN_BALLOONUSERCLICK = 0x405;
    public const Int32 NIN_KEYSELECT = 0x403;
    public const Int32 NIN_SELECT = 0x400;
    public const Int32 NIN_POPUPOPEN = 0x406;
    public const Int32 NIN_POPUPCLOSE = 0x407;

    public const Int32 NIIF_USER = 0x4;
    public const Int32 NIIF_NONE = 0x0;
    public const Int32 NIIF_INFO = 0x1;
    public const Int32 NIIF_WARNING = 0x2;
    public const Int32 NIIF_ERROR = 0x3;
    public const Int32 NIIF_LARGE_ICON = 0x20;

    public enum NotifyFlags { 
        NIF_MESSAGE = 0x01, 
        NIF_ICON = 0x02,
        NIF_TIP = 0x04,
        NIF_INFO = 0x10,
        NIF_STATE = 0x08, 
        NIF_GUID = 0x20, 
        NIF_SHOWTIP = 0x80 
        }

    public enum NotifyCommand { NIM_ADD = 0x0, NIM_DELETE = 0x2, NIM_MODIFY = 0x1, NIM_SETVERSION = 0x4}
    [StructLayout(LayoutKind.Sequential)]
    public struct NOTIFYICONDATA
    {
        public Int32 cbSize;
        public IntPtr hWnd;
        public Int32 uID;
        public NotifyFlags uFlags;
        public Int32 uCallbackMessage;
        public IntPtr hIcon;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)]
        public String szTip;
        public Int32 dwState;
        public Int32 dwStateMask;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 256)]
        public String szInfo;
        public Int32 uVersion;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 64)]
        public String szInfoTitle;
        public Int32 dwInfoFlags;
        public Guid guidItem; //> IE 6
        public IntPtr hBalloonIcon;
    }

    [DllImport("shell32.dll")]
    public static extern System.Int32 Shell_NotifyIcon(NotifyCommand cmd, ref NOTIFYICONDATA data);


    [StructLayout(LayoutKind.Sequential)]
    public struct RECT
    {
        public Int32 left;
        public Int32 top;
        public Int32 right;
        public Int32 bottom;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct NOTIFYICONIDENTIFIER
    {
        public Int32 cbSize;
        public IntPtr hWnd;
        public Int32 uID;
        public Guid guidItem;
    }

    //Works with Shell32.dll (version 6.1 or later)
    [DllImport("shell32.dll", SetLastError = true)]
    public static extern int Shell_NotifyIconGetRect([In]ref NOTIFYICONIDENTIFIER identifier, [Out]out RECT iconLocation);

添加图标：

//you only need this guid to identify your icon
private Guid guid;

//call only once to set the icon and create the guid.
private void AddIcon()
{
    guid = Guid.NewGuid();

    NOTIFYICONDATA data = new NOTIFYICONDATA();

    data.cbSize = Marshal.SizeOf(data);
    data.hWnd = this.Handle;
    data.guidItem = guid;
    data.uCallbackMessage = WM_MYMESSAGE; //This is the message sent to our app
    data.hIcon = Properties.Resources.myIcon;
    data.szTip = "Your text";

    data.uFlags = NotifyFlags.NIF_ICON | NotifyFlags.NIF_GUID | NotifyFlags.NIF_MESSAGE | NotifyFlags.NIF_TIP | 
                  NotifyFlags.NIF_SHOWTIP;

    Shell_NotifyIcon(NotifyCommand.NIM_ADD, ref data);

    data.uVersion = NOTIFYICON_VERSION_4;
    Shell_NotifyIcon(NotifyCommand.NIM_SETVERSION, ref data);
}

获取图标在屏幕坐标中的位置：

private void GetRectIcon()
{
    RECT rect = new RECT();
    NOTIFYICONIDENTIFIER notifyIcon = new NOTIFYICONIDENTIFIER();

    notifyIcon.cbSize = Marshal.SizeOf(notifyIcon);
    //only guid is needed
    notifyIcon.guidItem = guid;

    int hresult = Shell_NotifyIconGetRect(ref notifyIcon, out rect);

    //rect now has the position and size of icon
}

删除通知图标：

private void DeleteIcon()
{
    NOTIFYICONDATA data = new NOTIFYICONDATA();
    data.cbSize =   Marshal.SizeOf(data);
    data.uFlags = NotifyFlags.NIF_GUID;
    data.guidItem = guid;

    Shell_NotifyIcon(NotifyCommand.NIM_DELETE, ref data);
}

添加气球

private void AddBalloon()
{
    NOTIFYICONDATA data;
    data = new NOTIFYICONDATA();

    data.cbSize = Marshal.SizeOf(data);
    data.guidItem = guid;

    //Set custom icon for balloon or NIIF_NONE for no icon. You can use all the other 
    //NIIF_... for system icons
    data.dwInfoFlags = NIIF_USER;
    data.hBalloonIcon = Properties.Resources.myNewIcon;
    //text in balloon
    data.szInfo = "My text in balloon";
    //balloon title
    data.szInfoTitle = "Balloon title";
    //set the flags to be modified
    data.uFlags = NotifyFlags.NIF_INFO | NotifyFlags.NIF_SHOWTIP | NotifyFlags.NIF_GUID;

    Shell_NotifyIcon(NotifyCommand.NIM_MODIFY, ref data);
}

捕捉消息

protected override void WndProc(ref Message m)
{

    if (m.Msg == WM_MYMESSAGE)
    {
        //(Int32)m.LParam & 0x0000FFFF get the low 2 bytes of LParam, we dont need the high ones. 
        //(Int32)m.WParam & 0x0000FFFF is the X coordinate and 
        //((Int32)m.WParam & 0xFFFF0000) >> 16 the Y
        switch ((Int32)m.LParam & 0x0000FFFF) 
            {
            case NIN_BALLOONHIDE:

                break;
            case NIN_BALLOONSHOW:

                break;
            case NIN_BALLOONTIMEOUT:

                break;
            case NIN_BALLOONUSERCLICK:
                //user clicked on balloon

                break;
            case NIN_SELECT:
                //user left click on icon

                break;
            case WM_CONTEXTMENU:
                //user right click on icon

                break;

            //get what mouse messages you want
            //case WM_LBUTTONDOWN:
            //....

            default:

                break;
        }
    }

    base.WndProc(ref m);
}

非托管代码的力量

Answer 2

在 γηράσκω δ' αεί πολλά διδ 的回答的帮助下，我能够找到一个解决方案，让您使用标准 NotifyIcon 控件来确定图标的位置。它需要使用反射，因为它必须访问私有字段，因此依赖于 NotifyIcon 类的当前实现。我使用 .NET Framework 2.0 和 4.0 对其进行了测试。

using System;
using System.Reflection;
using System.Windows.Forms;
using System.Runtime.InteropServices;

sealed class NotifyIconHelper
{

    public static Rectangle GetIconRect(NotifyIcon icon)
    {
        RECT rect = new RECT();
        NOTIFYICONIDENTIFIER notifyIcon = new NOTIFYICONIDENTIFIER();

        notifyIcon.cbSize = Marshal.SizeOf(notifyIcon);
        //use hWnd and id of NotifyIcon instead of guid is needed
        notifyIcon.hWnd = GetHandle(icon);
        notifyIcon.uID = GetId(icon);

        int hresult = Shell_NotifyIconGetRect(ref notifyIcon, out rect);
        //rect now has the position and size of icon

        return new Rectangle(rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top);
    }

    [StructLayout(LayoutKind.Sequential)]
    private struct RECT
    {
        public Int32 left;
        public Int32 top;
        public Int32 right;
        public Int32 bottom;
    }

    [StructLayout(LayoutKind.Sequential)]
    private struct NOTIFYICONIDENTIFIER
    {
        public Int32 cbSize;
        public IntPtr hWnd;
        public Int32 uID;
        public Guid guidItem;
    }

    [DllImport("shell32.dll", SetLastError = true)]
    private static extern int Shell_NotifyIconGetRect([In]ref NOTIFYICONIDENTIFIER identifier, [Out]out RECT iconLocation);

    private static FieldInfo windowField = typeof(NotifyIcon).GetField("window", Reflection.BindingFlags.NonPublic | Reflection.BindingFlags.Instance);
    private static IntPtr GetHandle(NotifyIcon icon)
    {
        if (windowField == null) throw new InvalidOperationException("[Useful error message]");
        NativeWindow window = windowField.GetValue(icon) as NativeWindow;

        if (window == null) throw new InvalidOperationException("[Useful error message]");  // should not happen?
        return window.Handle;
    }

    private static FieldInfo idField = typeof(NotifyIcon).GetField("id", Reflection.BindingFlags.NonPublic | Reflection.BindingFlags.Instance);
    private static int GetId(NotifyIcon icon)
    {
        if (idField == null) throw new InvalidOperationException("[Useful error message]");
        return (int)idField.GetValue(icon);
    }

}