GDI Refresh Problem

[Franco Gustavo]

Hi,

How can I execute 2 GDI steps without update the screen and update them
togheter?.

Basically I have a form and I want to change the Form Region and change the
Form Location, later show the changes on the screen.

On the Following code you can see that the code is executed but where the
window was there is the rest of the window that wasn't cleaned, if you move
a window over it it disapears.

I want to avoid see every change I do on the screen because I'm running many
changes a seconds (Animation)

I tried many ways but still I can get a way to work.

Here is the small code. "See Next Post" (Uncomment try1 or try2)
Thanks,

namespace PrototipesAndTesting
{
public class AnimateNoFlick : System.Windows.Forms.Form
{
#region enums
public enum SetWindowPosFlags
{
SWP_NOSIZE = 0x0001,
SWP_NOMOVE = 0x0002,
SWP_NOZORDER = 0x0004,
SWP_NOREDRAW = 0x0008,
SWP_NOACTIVATE = 0x0010
}
#endregion

#region WINAPIs
[DllImport("user32.dll", CharSet=CharSet.Auto)]
private static extern bool SetWindowPos(IntPtr hWnd, IntPtr
hWndInsertAfter, int x, int y, int Width, int Height, SetWindowPosFlags
flags);
[DllImport("User32.dll", CharSet=CharSet.Auto)]
private static extern int SetWindowRgn(IntPtr hWnd, IntPtr hRgn, bool
redraw);
[DllImport("user32.dll", CharSet=CharSet.Auto)]
private static extern int InvalidateRect(IntPtr hWnd, IntPtr rc, int
bErase);
[DllImport("user32.dll", CharSet=CharSet.Auto)]
private static extern bool UpdateWindow(IntPtr hWnd);
#endregion

#region Variables Declaration
private System.Windows.Forms.Button button1;
private System.ComponentModel.Container components = null;
#endregion

#region Constructors
public AnimateNoFlick()
{
InitializeComponent();
}
#endregion

#region Initialization And Disposing
protected override void Dispose( bool disposing )
{
if( disposing )
{
if(components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}

#region Windows Form Designer generated code
private void InitializeComponent()
{
this.button1 = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// button1
//
this.button1.Location = new System.Drawing.Point(96, 64);
this.button1.Name = "button1";
this.button1.TabIndex = 2;
this.button1.Text = "button1";
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// AnimateNoFlick
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(280, 262);
this.Controls.Add(this.button1);
this.Location = new System.Drawing.Point(300, 100);
this.Name = "AnimateNoFlick";
this.StartPosition = System.Windows.Forms.FormStartPosition.Manual;
this.Text = "AnimateNoFlick";
this.ResumeLayout(false);

}
#endregion

private void button1_Click(object sender, System.EventArgs e)
{
bool bResult;
int iResult;

Rectangle stepRec = new Rectangle(300, 500, this.Width,
this.Height);
Region region = new Region(new Rectangle(30,30, 200, 200));

Graphics graphics = this.CreateGraphics();
IntPtr ptr = region.GetHrgn(graphics);
graphics.Dispose();

//Try 1
//bResult = SetWindowPos(this.Handle, IntPtr.Zero, stepRec.X,
stepRec.Y, stepRec.Width, stepRec.Height, SetWindowPosFlags.SWP_NOZORDER |
SetWindowPosFlags.SWP_NOACTIVATE | SetWindowPosFlags.SWP_NOREDRAW);
//iResult = SetWindowRgn(this.Handle, ptr, true);

//Try 2
iResult = SetWindowRgn(this.Handle, ptr, false);
bResult = SetWindowPos(this.Handle, IntPtr.Zero, stepRec.X,
stepRec.Y, stepRec.Width, stepRec.Height, SetWindowPosFlags.SWP_NOZORDER |
SetWindowPosFlags.SWP_NOACTIVATE);
InvalidateRect(this.Handle, IntPtr.Zero, 1);
UpdateWindow(this.Handle);
Application.DoEvents();
}
#endregion
}
}