//Fields
private int borderSize = 2;
private Size formSize; //Keep form size when it is minimized and restored.Since the form is resized because it takes into account the size of the title bar and borders.
Constructor
//Constructor
public Form1()
{
InitializeComponent();
CollapseMenu();
this.Padding = new Padding(borderSize);//Border size
this.BackColor = Color.FromArgb(98, 102, 244);//Border color
}
//Drag Form
[DllImport("user32.DLL", EntryPoint = "ReleaseCapture")]
private extern static void ReleaseCapture();
[DllImport("user32.DLL", EntryPoint = "SendMessage")]
private extern static void SendMessage(System.IntPtr hWnd, int wMsg, int wParam, int lParam);
private void panelTitleBar_MouseDown(object sender, MouseEventArgs e)
{
ReleaseCapture();
SendMessage(this.Handle, 0x112, 0xf012, 0);
}
Overridden methods
//Overridden methods
protected override void WndProc(ref Message m)
{
const int WM_NCCALCSIZE = 0x0083;//Standar Title Bar - Snap Window
const int WM_SYSCOMMAND = 0x0112;
const int SC_MINIMIZE = 0xF020; //Minimize form (Before)
const int SC_RESTORE = 0xF120; //Restore form (Before)
const int WM_NCHITTEST = 0x0084;//Win32, Mouse Input Notification: Determine what part of the window corresponds to a point, allows to resize the form.
const int resizeAreaSize = 10;
#region Form Resize
// Resize/WM_NCHITTEST values
const int HTCLIENT = 1; //Represents the client area of the window
const int HTLEFT = 10; //Left border of a window, allows resize horizontally to the left
const int HTRIGHT = 11; //Right border of a window, allows resize horizontally to the right
const int HTTOP = 12; //Upper-horizontal border of a window, allows resize vertically up
const int HTTOPLEFT = 13;//Upper-left corner of a window border, allows resize diagonally to the left
const int HTTOPRIGHT = 14;//Upper-right corner of a window border, allows resize diagonally to the right
const int HTBOTTOM = 15; //Lower-horizontal border of a window, allows resize vertically down
const int HTBOTTOMLEFT = 16;//Lower-left corner of a window border, allows resize diagonally to the left
const int HTBOTTOMRIGHT = 17;//Lower-right corner of a window border, allows resize diagonally to the right
///<Doc> More Information: https://docs.microsoft.com/en-us/windows/win32/inputdev/wm-nchittest </Doc>
if (m.Msg == WM_NCHITTEST)
{ //If the windows m is WM_NCHITTEST
base.WndProc(ref m);
if (this.WindowState == FormWindowState.Normal)//Resize the form if it is in normal state
{
if ((int)m.Result == HTCLIENT)//If the result of the m (mouse pointer) is in the client area of the window
{
Point screenPoint = new Point(m.LParam.ToInt32()); //Gets screen point coordinates(X and Y coordinate of the pointer)
Point clientPoint = this.PointToClient(screenPoint); //Computes the location of the screen point into client coordinates
if (clientPoint.Y <= resizeAreaSize)//If the pointer is at the top of the form (within the resize area- X coordinate)
{
if (clientPoint.X <= resizeAreaSize) //If the pointer is at the coordinate X=0 or less than the resizing area(X=10) in
m.Result = (IntPtr)HTTOPLEFT; //Resize diagonally to the left
else if (clientPoint.X < (this.Size.Width - resizeAreaSize))//If the pointer is at the coordinate X=11 or less than the width of the form(X=Form.Width-resizeArea)
m.Result = (IntPtr)HTTOP; //Resize vertically up
else //Resize diagonally to the right
m.Result = (IntPtr)HTTOPRIGHT;
}
else if (clientPoint.Y <= (this.Size.Height - resizeAreaSize)) //If the pointer is inside the form at the Y coordinate(discounting the resize area size)
{
if (clientPoint.X <= resizeAreaSize)//Resize horizontally to the left
m.Result = (IntPtr)HTLEFT;
else if (clientPoint.X > (this.Width - resizeAreaSize))//Resize horizontally to the right
m.Result = (IntPtr)HTRIGHT;
}
else
{
if (clientPoint.X <= resizeAreaSize)//Resize diagonally to the left
m.Result = (IntPtr)HTBOTTOMLEFT;
else if (clientPoint.X < (this.Size.Width - resizeAreaSize)) //Resize vertically down
m.Result = (IntPtr)HTBOTTOM;
else //Resize diagonally to the right
m.Result = (IntPtr)HTBOTTOMRIGHT;
}
}
}
return;
}
#endregion
//Remove border and keep snap window
if (m.Msg == WM_NCCALCSIZE && m.WParam.ToInt32() == 1)
{
return;
}
//Keep form size when it is minimized and restored. Since the form is resized because it takes into account the size of the title bar and borders.
if (m.Msg == WM_SYSCOMMAND)
{
/// <see cref="https://docs.microsoft.com/en-us/windows/win32/menurc/wm-syscommand"/>
/// Quote:
/// In WM_SYSCOMMAND messages, the four low - order bits of the wParam parameter
/// are used internally by the system.To obtain the correct result when testing
/// the value of wParam, an application must combine the value 0xFFF0 with the
/// wParam value by using the bitwise AND operator.
int wParam = (m.WParam.ToInt32() & 0xFFF0);
if (wParam == SC_MINIMIZE) //Before
formSize = this.ClientSize;
if (wParam == SC_RESTORE)// Restored form(Before)
this.Size = formSize;
}
base.WndProc(ref m);
}
Private methods
//Private methods
private void AdjustForm()
{
switch (this.WindowState)
{
case FormWindowState.Maximized: //Maximized form (After)
this.Padding = new Padding(8, 8, 8, 0);
break;
case FormWindowState.Normal: //Restored form (After)
if (this.Padding.Top != borderSize)
this.Padding = new Padding(borderSize);
break;
}
}
private void CollapseMenu()
{
if (this.panelMenu.Width > 200) //Collapse menu
{
panelMenu.Width = 100;
pictureBox1.Visible = false;
btnMenu.Dock = DockStyle.Top;
foreach (Button menuButton in panelMenu.Controls.OfType<Button>())
{
menuButton.Text = "";
menuButton.ImageAlign = ContentAlignment.MiddleCenter;
menuButton.Padding = new Padding(0);
}
}
else
{ //Expand menu
panelMenu.Width = 230;
pictureBox1.Visible = true;
btnMenu.Dock = DockStyle.None;
foreach (Button menuButton in panelMenu.Controls.OfType<Button>())
{
menuButton.Text = " " + menuButton.Tag.ToString();
menuButton.ImageAlign = ContentAlignment.MiddleLeft;
menuButton.Padding = new Padding(10, 0, 0, 0);
}
}
}
