improve:快捷调色盘

Ink Canvas/MainWindow_cs/MW_Colors.cs

@@ -1,4 +1,4 @@
-using Ink_Canvas.Helpers;
+using Ink_Canvas.Helpers;
 using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
@@ -131,6 +131,12 @@ namespace Ink_Canvas
             }
 
             double alpha = inkCanvas.DefaultDrawingAttributes.Color.A;
+            if (penType == 0 && Settings?.Canvas != null)
+            {
+                double settingAlpha = Settings.Canvas.InkAlpha;
+                if (settingAlpha >= 0 && settingAlpha <= 255)
+                    alpha = settingAlpha;
+            }
 
             if (penType == 0)
             {

Ink Canvas/MainWindow_cs/MW_Settings.cs

@@ -2337,9 +2337,8 @@ namespace Ink_Canvas
             var NowB = drawingAttributes.Color.B;
             // Trace.WriteLine(BitConverter.GetBytes(((Slider)sender).Value));
             drawingAttributes.Color = Color.FromArgb((byte)((Slider)sender).Value, NowR, NowG, NowB);
-            // drawingAttributes.Width = ((Slider)sender).Value / 2;
-            // Settings.Canvas.InkAlpha = ((Slider)sender).Value;
-            // SaveSettingsToFile();
+            Settings.Canvas.InkAlpha = ((Slider)sender).Value;
+            SaveSettingsToFile();
         }
 
         private void ComboBoxHyperbolaAsymptoteOption_SelectionChanged(object sender, SelectionChangedEventArgs e)