Message Filter : Form Action Event « GUI « VB.Net Tutorial

Message Filter
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
Imports System.Math

public class MessageFilter
   public Shared Sub Main
         Application.Run(New Form1)
   End Sub
End class
Public Class Form1
    Public Class NoLeftDownMessageFilter
        Implements IMessageFilter

        Public Function PreFilterMessage(ByRef m As System.Windows.Forms.Message) As Boolean Implements IMessageFilter.PreFilterMessage
            Const WM_LBUTTONDOWN As Long = &H201
            Return (m.Msg = WM_LBUTTONDOWN)
        End Function
    End Class

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim no_left_down_message_filter As New NoLeftDownMessageFilter
    End Sub

    Private Sub Form1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Click
        Application.UseWaitCursor = Not Application.UseWaitCursor
    End Sub
End Class
<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Partial Public Class Form1
    Inherits System.Windows.Forms.Form

    'Form overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()> _
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing AndAlso components IsNot Nothing Then
        End If
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(292, 273)
        Me.Name = "Form1"
        Me.Text = "UseMessageFilter"

    End Sub

End Class

14.50.Form Action Event
14.50.1.Message FilterMessage Filter
14.50.2.Show Form MessageShow Form Message
14.50.3.Form Events IllustrationForm Events Illustration
14.50.4.Form Resize: fixed ratioForm Resize: fixed ratio
14.50.5.Add Key event to Form windowAdd Key event to Form window
14.50.6.Close a FormClose a Form
14.50.7.Form mouse event: Mouse Enter, Mouse Down, Mouse Hover, Mouse, Move, Mouse Up, Mouse Wheel, Mouse LeaveForm mouse event: Mouse Enter, Mouse Down, Mouse Hover, Mouse, Move, Mouse Up, Mouse Wheel, Mouse Leave
14.50.8.Convert Mouse event to form caption drag and drop eventConvert Mouse event to form caption drag and drop event
14.50.9.Form Layout eventForm Layout event
14.50.10.Overrides OnNotifyMessage method
14.50.11.Form resize eventForm resize event