[C#][VB.NET]FullScreen the winform

static class FullScreenExtension { #region Struct struct FullScreenData { public FormBorderStyle FormBorderStyle { get; set; } public FormWindowState WindowState { get; set; }

    public FullScreenData(FormBorderStyle formBorderStyle, FormWindowState windowState):this()
    {
        this.FormBorderStyle = formBorderStyle;
        this.WindowState = windowState;
    }
} 
#endregion

#region Var
private static Dictionary<Form, FullScreenData> _fullScreenDataPool; 
#endregion

#region Private Property
private static Dictionary<Form, FullScreenData> m_FullScreenDataPool
{
    get
    {
        if (_fullScreenDataPool == null)
            _fullScreenDataPool = new Dictionary<Form, FullScreenData>();
        return _fullScreenDataPool;
    }
}

#endregion

#region Public Method
public static void FullScreen(this Form frm)
{
    if (m_FullScreenDataPool.ContainsKey(frm))
        return;
    m_FullScreenDataPool.Add(frm, new FullScreenData(frm.FormBorderStyle,frm.WindowState));
    frm.FormBorderStyle = FormBorderStyle.None;
    frm.WindowState = FormWindowState.Normal;
    frm.WindowState = FormWindowState.Maximized;
}

public static void UnFullScreen(this Form frm)
{
    if (!m_FullScreenDataPool.ContainsKey(frm))
        return;
    FullScreenData fd = m_FullScreenDataPool[frm];        
    frm.WindowState = fd.WindowState;
    frm.FormBorderStyle = fd.FormBorderStyle;
    m_FullScreenDataPool.Remove(frm);
} 
#endregion

}

Module FullScreenExtension

#Region “Structure” Structure FullScreenData Private _formBorderStyle As FormBorderStyle Private _windowState As FormWindowState

    Public Property FormBorderStyle() As FormBorderStyle
        Get
            Return _formBorderStyle
        End Get
        Set(ByVal value As FormBorderStyle)
            _formBorderStyle = value
        End Set
    End Property

    Public Property WindowState() As FormWindowState
        Get
            Return _windowState
        End Get
        Set(ByVal value As FormWindowState)
            _windowState = value
        End Set
    End Property

    Sub New(ByVal formBorderStyle As FormBorderStyle, ByVal windowState As FormWindowState)
        With Me
            .FormBorderStyle = formBorderStyle
            .WindowState = windowState
        End With
    End Sub
End Structure

#End Region

#Region “Var” Private _fullScreenDataPool As Dictionary(Of Form, FullScreenData) #End Region

#Region “Private Property” Private ReadOnly Property m_FullScreenDataPool() As Dictionary(Of Form, FullScreenData) Get If _fullScreenDataPool Is Nothing Then _fullScreenDataPool = New Dictionary(Of Form, FullScreenData) End If Return _fullScreenDataPool End Get End Property #End Region

#Region “Public Method” <Extension()> _ Sub FullScreen(ByVal frm As Form) If m_FullScreenDataPool.ContainsKey(frm) Then Return End If With frm m_FullScreenDataPool.Add(frm, New FullScreenData(.FormBorderStyle, .WindowState)) .FormBorderStyle = FormBorderStyle.None .WindowState = FormWindowState.Normal .WindowState = FormWindowState.Maximized End With End Sub

&lt;Extension()&gt; _
Sub UnFullScreen(ByVal frm As Form)
    If Not m_FullScreenDataPool.ContainsKey(frm) Then
        Return
    End If
    With frm
        Dim fd As FullScreenData = m_FullScreenDataPool(frm)
        .WindowState = fd.WindowState
        .FormBorderStyle = fd.FormBorderStyle
        m_FullScreenDataPool.Remove(frm)
    End With
End Sub

#End Region

End Module

namespace FullScreenExtensionDemo { public partial class Form1 : Form { public Form1() { InitializeComponent(); }

    private void btnFullScreen_Click(object sender, EventArgs e)
    {
        this.FullScreen();
        
    }

    private void btnUnFullScreen_Click(object sender, EventArgs e)
    {
        this.UnFullScreen();   
    }

}

}

Private Sub btnFullScreen_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFullScreen.Click
    Me.FullScreen()
End Sub

Private Sub btnUnFullScreen_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUnFullScreen.Click
    Me.UnFullScreen()
End Sub

End Class