Improved the DPI awareness (display scaling) in the TreeViewAdv control.

Author: moellerm

External/Aga.Controls/Tree/TreeViewAdv.Designer.cs

@@ -41,7 +41,8 @@ private void CreatePens()
 		{
 			CreateLinePen();
 			CreateMarkPen();
-		}
+            CreateLightGrayPen();
+        }
 
 		private void CreateMarkPen()
 		{
@@ -59,7 +60,14 @@ private void CreateLinePen()
 		{
 			_linePen = new Pen(_lineColor);
 			_linePen.DashStyle = DashStyle.Dot;
-		}
+            _linePen.Width = GetScaledSize(1, false);
+        }
+
+        private void CreateLightGrayPen()
+        {
+            _lightGrayPen = new Pen(Color.FromArgb(247, 247, 247));
+            _lightGrayPen.Width = GetScaledSize(1, false);
+        }
 
         protected override void OnPaint(PaintEventArgs e)
         {
@@ -136,7 +144,7 @@ private void DrawRow(PaintEventArgs e, ref DrawContext context, int row, Rectang
 			OnRowDraw(e, node, context, row, rowRect);
 
 			if ((GridLineStyle & GridLineStyle.Horizontal) == GridLineStyle.Horizontal) {
-				e.Graphics.DrawLine(LightGrayPen, 0, rowRect.Bottom, e.Graphics.ClipBounds.Right, rowRect.Bottom);
+				e.Graphics.DrawLine(_lightGrayPen, 0, rowRect.Bottom, e.Graphics.ClipBounds.Right, rowRect.Bottom);
       }
 
 			if (FullRowSelect)
@@ -164,8 +172,7 @@ private void DrawRow(PaintEventArgs e, ref DrawContext context, int row, Rectang
 			DrawNode(node, context);
 		}
 
-		private Brush GrayBrush = new SolidBrush(Color.FromArgb(240, 240, 240));
-		private Pen LightGrayPen = new Pen(Color.FromArgb(247, 247, 247));
+		private Brush GrayBrush = new SolidBrush(Color.FromArgb(240, 240, 240));		
 
 		private void DrawVerticalGridLines(Graphics gr, int y)
 		{
@@ -260,7 +267,8 @@ private void DrawLines(Graphics gr, TreeNodeAdv node, Rectangle rowRect)
 			{
 				int level = curNode.Level;
 				int scaledIndent = node.Tree.GetScaledSize(_indent, false);
-				int x = (level - 1) * scaledIndent + NodePlusMinus.ImageSize / 2 + LeftMargin;
+				int x = (level - 1) * scaledIndent + 
+                    node.Tree.GetScaledSize(NodePlusMinus.ImageSize, false) / 2 + LeftMargin;
 				int width = node.Tree.GetScaledSize(NodePlusMinus.Width - NodePlusMinus.ImageSize / 2, false);
 				int y = rowRect.Y;
 				int y2 = y + rowRect.Height;

External/Aga.Controls/Tree/TreeViewAdv.Draw.cs

@@ -30,6 +30,7 @@ public partial class TreeViewAdv : Control
 		private const int DividerCorrectionGap = -2;
 
 		private Pen _linePen;
+        private Pen _lightGrayPen;
 		private Pen _markPen;
 		private bool _suspendUpdate;
 		private bool _needFullUpdate;
@@ -256,7 +257,7 @@ public void SetDPI()
 		{
 			// https://msdn.microsoft.com/en-us/library/windows/desktop/dn469266(v=vs.85).aspx
 			const int _default_dpi = 96;
-			Graphics g = this.CreateGraphics();
+			Graphics g = Graphics.FromHwnd(IntPtr.Zero);
 
 			try
 			{