* UINavMenu：在自定义风格时，可设置FillColor调整背景色

SunnyUI.Demo/FMain.Designer.cs

@@ -52,7 +52,7 @@
             // 
             this.Header.Controls.Add(this.uiAvatar);
             this.Header.Controls.Add(this.uiLogo1);
-            this.Header.MenuStyle = Sunny.UI.UIMenuStyle.Custom;
+            this.Header.FillColor = System.Drawing.Color.Navy;
             treeNode1.Name = "节点0";
             treeNode1.Text = "控件";
             treeNode2.Name = "节点1";

SunnyUI/Controls/UINavBar.cs

@@ -130,6 +130,7 @@ namespace Sunny.UI
 
         private Color backColor = Color.FromArgb(56, 56, 56);
 
+        [DefaultValue(typeof(Color), "56, 56, 56")]
         public override Color BackColor
         {
             get => backColor;
@@ -141,6 +142,19 @@ namespace Sunny.UI
             }
         }
 
+        private Color fillColor = Color.FromArgb(56, 56, 56);
+
+        [DefaultValue(typeof(Color), "56, 56, 56")]
+        public Color FillColor
+        {
+            get => fillColor;
+            set
+            {
+                fillColor = value;
+                Invalidate();
+            }
+        }
+
         private void SetMenuStyle(UIMenuColor uiColor)
         {
             foreColor = uiColor.UnSelectedForeColor;
@@ -279,6 +293,8 @@ namespace Sunny.UI
             base.OnPaint(e);
 
             e.Graphics.Clear(BackColor);
+            if (StyleCustomMode) e.Graphics.Clear(FillColor);
+
             NodeX = 0;
             NodeY = Height - NodeSize.Height;