向 winforms 添加手势支持 - 在这里解决：
http://portal.fke.utm.my/libraryfke/files/1387_LIEWHONCHIN2011.pdf
'Imports System.Security.Permissions
'Imports System.Runtime.InteropServices
Private first_point As New Point()
Private second_point As New Point()
Private iArguments As Integer = 0
Private Const ULL_ARGUMENTS_BIT_MASK As Int64 = &HFFFFFFFFL
Private Const WM_GESTURENOTIFY As Integer = &H11A
Private Const WM_GESTURE As Integer = &H119
Private Const GC_ALLGESTURES As Integer = &H1
Private Const GID_BEGIN As Integer = 1
Private Const GID_END As Integer = 2
Private Const GID_ZOOM As Integer = 3
Private Const GID_PAN As Integer = 4
Private Const GID_ROTATE As Integer = 5
Private Const GID_TWOFINGERTAP As Integer = 6
Private Const GID_PRESSANDTAP As Integer = 7
Private Const GF_BEGIN As Integer = &H1
Private Const GF_INERTIA As Integer = &H2
Private Const GF_END As Integer = &H4
Private Structure GESTURECONFIG
Public dwID As Integer
Public dwWant As Integer
Public dwBlock As Integer
End Structure
Private Structure POINTS
Public x As Short
Public y As Short
End Structure
Private Structure GESTUREINFO
Public cbSize As Integer
Public dwFlags As Integer
Public dwID As Integer
Public hwndTarget As IntPtr
<MarshalAs(UnmanagedType.Struct)>
Friend ptsLocation As POINTS
Public dwInstanceID As Integer
Public dwSequenceID As Integer
Public ullArguments As Int64
Public cbExtraArgs As Integer
End Structure
<DllImport("user32")> _
Private Shared Function SetGestureConfig(ByVal hWnd As IntPtr, ByVal dwReserved As Integer, ByVal cIDs As Integer, ByRef pGestureConfig As GESTURECONFIG, ByVal cbSize As Integer) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function
<DllImport("user32")>
Private Shared Function GetGestureInfo(ByVal hGestureInfo As IntPtr, ByRef pGestureInfo As GESTUREINFO) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function
Private _gestureConfigSize As Integer
Private _gestureInfoSize As Integer
<SecurityPermission(SecurityAction.Demand)>
Private Sub SetupStructSizes()
_gestureConfigSize = Marshal.SizeOf(New GESTURECONFIG())
_gestureInfoSize = Marshal.SizeOf(New GESTUREINFO())
End Sub
<PermissionSet(SecurityAction.Demand, Name:="FullTrust")>
Protected Overrides Sub WndProc(ByRef m As Message)
Dim handled As Boolean
Select Case m.Msg
Case WM_GESTURENOTIFY
Dim gc As New GESTURECONFIG()
gc.dwID = 0
gc.dwWant = GC_ALLGESTURES
gc.dwBlock = 0
Dim bResult As Boolean = SetGestureConfig(Handle, 0, 1, gc, _gestureConfigSize)
If Not bResult Then
Throw New Exception("Error in execution of SetGestureConfig")
End If
handled = True
Case WM_GESTURE
handled = DecodeGesture(m)
Case Else
handled = False
End Select
MyBase.WndProc(m)
If handled Then
Try
m.Result = New IntPtr(1)
Catch excep As Exception
Debug.Print("Could not allocate result ptr")
Debug.Print(excep.ToString())
End Try
End If
End Sub
Private Function DecodeGesture(ByRef m As Message) As Boolean
Dim gi As GESTUREINFO
Try
gi = New GESTUREINFO()
Catch excep As Exception
Debug.Print("Could not allocate resources to decode gesture")
Debug.Print(excep.ToString())
Return False
End Try
gi.cbSize = _gestureInfoSize
If Not GetGestureInfo(m.LParam, gi) Then
Return False
End If
Select Case gi.dwID
Case GID_BEGIN, GID_END
Case GID_TWOFINGERTAP
'Receipt.Show()
'Invalidate()
Case GID_ZOOM
Select Case gi.dwFlags
Case GF_BEGIN
iArguments = CInt(Fix(gi.ullArguments And
ULL_ARGUMENTS_BIT_MASK))
first_point.X = gi.ptsLocation.x
first_point.Y = gi.ptsLocation.y
first_point = PointToClient(first_point)
Case Else
second_point.X = gi.ptsLocation.x
second_point.Y = gi.ptsLocation.y
second_point = PointToClient(second_point)
RaiseEvent GestureHappened(Me, New GestureEventArgs With {.Operation = Gestures.Pan, .FirstPoint = first_point, .SecondPoint = second_point})
'Invalidate()
'MsgBox("zoom")
End Select
Case GID_PAN
Select Case gi.dwFlags
Case GF_BEGIN
first_point.X = gi.ptsLocation.x
first_point.Y = gi.ptsLocation.y
first_point = PointToClient(first_point)
Case Else
second_point.X = gi.ptsLocation.x
second_point.Y = gi.ptsLocation.y
second_point = PointToClient(second_point)
RaiseEvent GestureHappened(Me, New GestureEventArgs With {.Operation = Gestures.Pan, .FirstPoint = first_point, .SecondPoint = second_point})
'Invalidate()
'MsgBox("pan")
End Select
Case GID_PRESSANDTAP
'If gi.dwFlags = GF_BEGIN Then
' Invalidate()
'End If
Case GID_ROTATE
'Select Case gi.dwFlags
' Case GF_BEGIN
' iArguments = 0
' Case Else
' first_point.X = gi.ptsLocation.x
' first_point.Y = gi.ptsLocation.y
' first_point = PointToClient(first_point)
' Invalidate()
'End Select
End Select
Return True
End Function
Public Enum Gestures
Pan
Zoom
End Enum
Public Class GestureEventArgs
Inherits EventArgs
Public Property Operation As Gestures
Public Property FirstPoint As Point
Public Property SecondPoint As Point
End Class
Public Event GestureHappened(sender As Object, e As GestureEventArgs)
