C#

System.ArgumentException: Parameter is not valid.
   at System.Drawing.Graphics.set_Transform(Matrix value)
   at ATW.Sprite.Draw() in C:\Users\Laurens\Documents\School\P2\PT12\Around the World\Sprite.cs:line 55
   at ATW.Airplane.Draw() in C:\Users\Laurens\Documents\School\P2\PT12\Around the World\Airplane.cs:line 29
   at ATW.Engine.OnPaint(PaintEventArgs e) in C:\Users\Laurens\Documents\School\P2\PT12\Around the World\Engine.cs:line 300
   at System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer, Boolean disposeEventArgs)
   at System.Windows.Forms.Control.WmPaint(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at System.Windows.Forms.ContainerControl.WndProc(Message& m)
   at System.Windows.Forms.Form.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

public void SetSize(float xInches, float yInches)
{
    Graphics g = Graphics.FromHwnd(this.Handle);
    this.Size = new Size((int)(xInches * g.DpiX), (int)(yInches * g.DpiY));
    g.Dispose();
}

Pete O`Hanlon wrote:

Assuming you're using WinForms, you can assume that there are 72 dots (pixels) per inch, so multiply up by 72.

SK Genius wrote:

This bypasses the "you have already posted this message" message, and when the page eventually loads, you have two messages, or more