Added 'FlatBorder' property to DarkForm

FlatBorder can be used to set whether a single pixel border is rendered
around the form or not.

DarkUI/Forms/DarkForm.cs

@@ -1,9 +1,34 @@
-using System.Windows.Forms;
+using System.ComponentModel;
+using System.Drawing;
+using System.Windows.Forms;
 
 namespace DarkUI
 {
     public class DarkForm : Form
     {
+        #region Field Region
+
+        private bool _flatBorder;
+
+        #endregion
+
+        #region Property Region
+
+        [Category("Appearance")]
+        [Description("Determines whether a single pixel border should be rendered around the form.")]
+        [DefaultValue(false)]
+        public bool FlatBorder
+        {
+            get { return _flatBorder; }
+            set
+            {
+                _flatBorder = value;
+                Invalidate();
+            }
+        }
+
+        #endregion
+
         #region Constructor Region
 
         public DarkForm()
@@ -12,5 +37,25 @@ namespace DarkUI
         }
 
         #endregion
+
+        #region Paint Region
+
+        protected override void OnPaintBackground(PaintEventArgs e)
+        {
+            base.OnPaintBackground(e);
+
+            if (!_flatBorder)
+                return;
+
+            var g = e.Graphics;
+
+            using (var p = new Pen(Colors.DarkBorder))
+            {
+                var modRect = new Rectangle(ClientRectangle.Location, new Size(ClientRectangle.Width - 1, ClientRectangle.Height - 1));
+                g.DrawRectangle(p, modRect);
+            }
+        }
+
+        #endregion
     }
 }

Example/Forms/MainForm.Designer.cs

@@ -547,6 +547,7 @@
             this.Controls.Add(this.toolMain);
             this.Controls.Add(this.mnuMain);
             this.Font = new System.Drawing.Font("Segoe UI", 9F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
+            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
             this.MainMenuStrip = this.mnuMain;
             this.MinimumSize = new System.Drawing.Size(640, 480);
             this.Name = "MainForm";