vb.net add Aero Snap property in my borderless form

Question

i am try to make border less form' it's work fine. but i cant add "Aero Snap" property for it. i am try different method for make borderless form. but they are not resize smoothly. that method is only best way for smooth resize. i want it maximize when it drag upper side of screen. how i did that here is my whole code.
Imports System.Runtime.InteropServices

Public Class Form2

Public Shared Function ReleaseCapture() As Boolean
End Function

Public Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer
End Function

Private Const HTCAPTION As Integer = 2

Private Const WM_NCLBUTTONDOWN As Integer = &HA1
Protected Overrides ReadOnly Property CreateParams As CreateParams
Get
Dim cp As CreateParams = MyBase.CreateParams
cp.Style = cp.Style Or &H20000 '<;--- Minimize borderless form from taskbar
Return cp
End Get
End Property

Private Sub Form1_MouseDown(sender As Object, e As MouseEventArgs) Handles Me.MouseDown

If locked = True Then  
    locked = False  
    Exit Sub  
End If  

If direction_ = ResizeDirection.None Then  
ElseIf direction_ = ResizeDirection.title Then  
    MoveForm()  
Else  
    ResizeForm()  
End If

End Sub
Private Sub MoveForm()
ReleaseCapture()
SendMessage(Me.Handle, WM_NCLBUTTONDOWN, HTCAPTION, 0)
Invalidate()
End Sub
Private Sub ResizeForm()
' mouse_down = True
ReleaseCapture()
SendMessage(Me.Handle, WM_NCLBUTTONDOWN, direction_, 0)
End Sub

Dim frame_width As Integer = 3
Dim title_width As Integer = 31
Public Enum ResizeDirection
None = 0
title = 1
Left = 10
TopLeft = 13
Top = 12
TopRight = 14
Right = 11
BottomRight = 17
Bottom = 15
BottomLeft = 16
End Enum
Dim direction_ As ResizeDirection
Dim locked As Boolean = False
Private Sub Form1_MouseMove(sender As Object, e As MouseEventArgs) Handles Me.MouseMove
If Me.WindowState = FormWindowState.Maximized Then
If e.Y < title_width Then
direction_ = ResizeDirection.title
Else
direction_ = ResizeDirection.None
End If
Cursor = Cursors.Default
Exit Sub
End If

If e.Y < frame_width Then  
    If e.X < frame_width Then  
        Cursor = Cursors.SizeNWSE  
        direction_ = ResizeDirection.TopLeft  
    ElseIf e.X > Me.Width - frame_width Then  
        Cursor = Cursors.SizeNESW  
        direction_ = ResizeDirection.TopRight  
    Else  
        Cursor = Cursors.SizeNS  
        direction_ = ResizeDirection.Top  
    End If  
ElseIf e.Y > Me.Height - frame_width Then  
    If e.X < frame_width Then  
        Cursor = Cursors.SizeNESW  
        direction_ = ResizeDirection.BottomLeft  
    ElseIf e.X > Me.Width - frame_width Then  
        Cursor = Cursors.SizeNWSE  
        direction_ = ResizeDirection.BottomRight  
    Else  
        Cursor = Cursors.SizeNS  
        direction_ = ResizeDirection.Bottom  
    End If  
ElseIf e.X < frame_width Then  
    Cursor = Cursors.SizeWE  
    direction_ = ResizeDirection.Left  
ElseIf e.X > Me.Width - frame_width Then  
    Cursor = Cursors.SizeWE  
    direction_ = ResizeDirection.Right  
Else  
    If e.Y < title_width Then  
        direction_ = ResizeDirection.title  
    Else  
        direction_ = ResizeDirection.None  
    End If  
    Cursor = Cursors.Default  
End If

End Sub
Private Sub BTN_MINIMIZE_Click(sender As Object, e As EventArgs) Handles BTN_MINIMIZE.Click
Me.WindowState = FormWindowState.Minimized
End Sub
Private Sub BTN_MAXIMIZE_Click(sender As Object, e As EventArgs) Handles BTN_MAXIMIZE.Click
' Dim Hd As Integer = 6
If Me.WindowState = FormWindowState.Maximized Then

    Me.WindowState = FormWindowState.Normal  
    '  Panel_TITLE.Height -= Hd  
    '  BTN_MINIMIZE.Top -= Hd  
    '  BTN_MAXIMIZE.Top -= Hd  
    ' BTN_CLOSE.Top -= Hd  

    ' SplitContainer1.Top -= Hd  
    '  SplitContainer1.Height -= Hd  
Else  
      
    ' Me.ControlBox = True  
    Me.WindowState = FormWindowState.Maximized  
    '  Me.ControlBox = False  
    '   Panel_TITLE.Height += Hd  
    '   BTN_MINIMIZE.Top += Hd  
    '  BTN_MAXIMIZE.Top += Hd  
    ' BTN_CLOSE.Top += Hd  

    '  SplitContainer1.Top += Hd  
    '  SplitContainer1.Height += Hd  
End If

End Sub
Private Sub BTN_CLOSE_Click(sender As Object, e As EventArgs) Handles BTN_CLOSE.Click
Application.Exit()
End Sub

'===============================================================================================================

Public Shared Function FindWindowEx(ByVal hwndParent As IntPtr, ByVal hwndChildAfter As IntPtr, ByVal lpszClass As String, ByVal lpszWindow As String) As IntPtr
End Function

Public Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal uMsg As Integer, ByVal wParam As Integer, ByVal lParam As String) As Integer
End Function

Private Sub Form1_Resize(sender As Object, e As EventArgs) Handles Me.Resize
' TextBox1.Text = Cursor.Position.ToString + "%%%"
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Me.FormBorderStyle = FormBorderStyle.None
Me.ControlBox = False
Me.BackColor = SystemColors.ControlDark

Me.ResizeRedraw = True  
Me.SetStyle(ControlStyles.AllPaintingInWmPaint, True)  

Dim rrr As Rectangle = Screen.FromRectangle(Me.Bounds).WorkingArea  
rrr.Width += 18  
rrr.Height -= 1  
Me.MaximumSize = rrr.Size

End Sub

Private Sub Form1_Move(sender As Object, e As EventArgs) Handles Me.Move
If Me.Top = 0 Then

    ReleaseCapture()  
    SendMessage(Me.Handle, WM_NCLBUTTONDOWN, HTCAPTION, 0)  
    ' Invalidate()  

    locked = True  

Else  
    locked = False  
End If

End Sub
End Class

Answer

You can add Aero Snap by adding the WS_THICKFRAME style =>

Protected Overrides ReadOnly Property CreateParams As CreateParams  
    Get  
        Dim cp As CreateParams = MyBase.CreateParams  
        If True Then  
            cp.Style = cp.Style Or WS_THICKFRAME Or WS_CAPTION  
        End If  
        Return cp  
    End Get  
End Property  
  
Public Const WS_THICKFRAME = &H40000  
Public Const WS_CAPTION = &HC00000  

Protected Overrides Sub WndProc(ByRef m As Message)  
    If m.Msg = WM_NCHITTEST Then  
        m.Result = New IntPtr(HTCAPTION)          
    ElseIf m.Msg = WM_NCCALCSIZE Then            
        m.Result = CType(0, IntPtr)  
    Else  
        MyBase.WndProc(m)  
    End If  
End Sub

vb.net add Aero Snap property in my borderless form

1 answer