It took a long time to pay attention to Application's AddMessageFilter, bitterly poor in your own basis, and did not test the results. Today, I saw the post, some people wanted to block the right-click message in the form of TextBox, so he represented this topic. Just still don't have any good results, you can only be realized.
Application.AddMessageFilter's main function is to add a message filter to monitor these messages when the Windows message is transmitted to the target.
(Hey, I originally want to say these meanings according to my own understanding, I am afraid that I am mistaken, and I have a lesson, I will take care of MSDN. Poor me, it is not a professional, I can only It is customary, and the 僧 不 不, the country is wearing a tie into the city, which is poor.)
Note: Adding a message filter to the application will reduce performance. (I am a warning, I generally use it, use it, manage it)
Using Application.addMessageFilter and the general method call different, its parameter message has such a request: To prevent scheduling a message, the value parameter instance that passes to the method must rewrite the PREFILTERMESSAGE method with the code to process the message. This method must return false.
Take the right-click message on the Movie FORM. Take the main practice below.
First, implement the iMessageFilter interface. as follows.
Why did you have a property that deliver FORM, as long as it is used to determine whether the current control is used. This effect is not ideal and needs to be improved. Originally, it is not necessary to introduce this attribute. Use the message.getlparam method to know the current message object is TEXTBOX. Pity I don't know how to write that Structure, if you give it out to correct, the little person is grateful.
Public Class TextBoxRbuttonMessageFilter
Implements system.windows.forms.imsSagefilter
Const WM_RBUTTONDOWN AS INTEGER = & H204
Const WM_RBUTTONUP AS INTEGER = & H205
Private M_Form As System.Windows.Forms.form
Public Writeonly Property [Form] () as system.windows.forms.form
Set (Byval Value As System.Windows.Forms.form)
M_Form = Value
End set
End Property
Public Function RButtonFilterMessage (byref m as system.windows.forms.Message)
As Boolean Implements System.windows.Forms.IMessageFilter.prefilterMessage
IF (M.MSG = WM_RBUTTONDOWN ORELSE M.MSG = WM_RBUTTONUP) ANDALSO M_FORM.ActiveControl.gettype.name.Equals ("TextBox") THEN
Return True
Else
Return False
END IF
END FUNCTION
END CLASS
Second, add a message filter to the application's message pump.
#Region "Windows Form Designer Generated Code"
Public Sub New ()
Mybase.new ()
'This call is required for the Windows Form Designer. InitializeComponent ()
'Add any initialization after INITIALIZECOMPONENT ()
mmsgfilter.form = me
System.windows.Forms.Application.addMessageFilter (mmsgfilter)
End Sub
......
#End region
Private MMSGFilter As New TextBoxRbuttonMessageFilter
It's that simple. The question is how to use Message.Getlparam, please advise.
Third, use Handle instead of ActiveControl
#Region "Windows Form Designer Generated Code"
Public Sub New ()
Mybase.new ()
'This call is required for the Windows Form Designer.
InitializeComponent ()
'Add any initialization after INITIALIZECOMPONENT ()
Msgfilterinit ()
End Sub
.......
#End region
Private MMSGFilter As New TextBoxRbuttonMessageFilter
Private sub msgfilterinit ()
DIM CTR as system.windows.forms.control
For Each Ctr in Me.Controls
IF Typeof Ctr is TextBox Then
MMSGFilter.SetfilterHandles (Ctr.Handle)
END IF
NEXT
System.windows.Forms.Application.addMessageFilter (mmsgfilter)
End Sub
END CLASS
Public Class TextBoxRbuttonMessageFilter
Implements system.windows.forms.imsSagefilter
Const WM_RBUTTONDOWN AS INTEGER = & H204
Const WM_RBUTTONUP AS INTEGER = & H205
Private m_hwnds as new hashtable
Public SUB SETFILTERHANDLES (BYVAL MHWND AS INTPTR)
m_hwnds.add (MHWND, NOTHING)
End Sub
Public Function RButtonFilterMessage (byref m as system.windows.forms.Message) _
As Boolean Implements System.windows.Forms.IMessageFilter.prefilterMessage
IF (M.MSG = WM_RBUTTONDOWN ORELSE M.MSG = WM_RBUTTONUP) Andalso M_HWNDS.CONTAINS (M.HWND) THEN
Return True
Else
Return False
END IF
END FUNCTION
END CLASS
