求教—vb中API函数Shell_NotifyIcon各参数作用

Private Declare Function Shell_NotifyIcon Lib "shell32.dll" Alias "Shell_NotifyIconA" (ByVal dwMessage As Long, lpData As NOTIFYICONDATA) As Long
'dwMessage指定你要加入、删除、还是修改图标 分别为NIM_ADD、NIM_DELETE和NIM_MODIFY
'lpData指向NOTIFYICONDATA类型变量的指针
Private Const WM_USER As Long = &H400
Private Const NIF_ICON = &H2          'NIF_ICON指定hIcon有效
Private Const NIF_MESSAGE = &H1      'NIF_MESSAGE指定uCallbackMessage有效
Private Const NIF_TIP = &H4          'NIF_TIP指定szTip有效
Private Const WM_MOUSEMOVE As Long = &H200
Private Const NIM_ADD = &H0
Private Const NIF_INFO = &H10
Private Const NIM_MODIFY = &H1
Private Enum bFlag
    NIIF_NONE = &H0
    NIIF_INFO = &H1
    NIIF_WARNING = &H2
    NIIF_ERROR = &H3
    NIIF_EXEICON = &H4
    NIIF_GUID = &H5
    NIIF_ICON_MASK = &HF
    NIIF_NOSOUND = &H10
End Enum
Private Type NOTIFYICONDATA
    cbSize As Long  'cbSize是NOTIFYICONDATA结构的大小
    hwnd As Long    'hWnd是当前窗口的句柄
    uID As Long      'uID指定图标的标识符
&