Making Winforms Fullscreen

11,461

The trick is to obtain the HwndSource and call its AddHook() method. This works:

Imports System.Windows.Interop

Class Window1
    Protected Overrides Sub OnSourceInitialized(ByVal e As System.EventArgs)
        MyBase.OnSourceInitialized(e)
        DirectCast(PresentationSource.FromVisual(Me), HwndSource).AddHook(AddressOf WndProc)
    End Sub

    Private Const WM_SYSCOMMAND As Integer = &H112
    Private Const SC_MAXIMIZE As Integer = &HF030

    Private Function WndProc(ByVal hWnd As IntPtr, ByVal msg As Integer, ByVal wp As IntPtr, ByVal lp As IntPtr, ByRef handled As Boolean) As IntPtr
        If msg = WM_SYSCOMMAND AndAlso wp.ToInt32() = SC_MAXIMIZE Then
            Me.ResizeMode = ResizeMode.NoResize
            Me.WindowStyle = WindowStyle.None
            Me.WindowState = WindowState.Maximized
            handled = True
        End If
    End Function

End Class

The same code for a Winforms Form:

Public Class Form1
    Private Const WM_SYSCOMMAND As Integer = &H112
    Private Const SC_MAXIMIZE As Integer = &HF030

    Protected Overrides Sub WndProc(ByRef m As Message)
        If m.Msg = WM_SYSCOMMAND AndAlso m.WParam.ToInt32() = SC_MAXIMIZE Then
            Me.FormBorderStyle = FormBorderStyle.None
            Me.WindowState = FormWindowState.Maximized
            Return
        End If
        MyBase.WndProc(m)
    End Sub

    Protected Overrides Function ProcessCmdKey(ByRef msg As Message, ByVal keyData As Keys) As Boolean
        '' Restore window when the user presses Escape
        If Me.WindowState = FormWindowState.Maximized AndAlso keyData = Keys.Escape Then
            Me.FormBorderStyle = Windows.Forms.FormBorderStyle.Sizable
            Me.WindowState = FormWindowState.Normal
        End If
        Return MyBase.ProcessCmdKey(msg, keyData)
    End Function

End Class
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giodamelio
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giodamelio

I am a 18 year old with many interests including computer programming, web developing, robotics and AI(artificial intelligent) and quantum computing. I program in vb.net, python, php, javascript and HTML. My favorite quote. "Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the universe trying to build bigger and better idiots. So far, the universe is winning." - Rick Cook

Updated on June 04, 2022

Comments

  • giodamelio
    giodamelio almost 2 years

    I need to make a winform full screen. This is what i found online.

    1. Hook WinProc to catch WM_SYSCOMMAND
    
    2. Check wParam == SC_MAXIMIZE and then
    
    3. Set my windiw's attributes
    
    Me.ResizeMode = ResizeMode.NoResize
    
    Me.WindowStyle = WindowStyle.None
    
    Me.WindowState = WindowState.Maximized
    

    I am fairly new to vb.net and do not know how to do Steps 1 or 2. Can someone give me a snippet or point me in the right direction?

    Thanks giodamelio