关于ToString()、ToKnowColor()及属性返回值为类类型的理解

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Linq;
  4 using System.Text;
  5 using System.Drawing;
  6 using System.Windows.Forms;
  7 
  8 namespace ColorScroll
  9 {
 10     class ColorScroll:Form
 11     {
 12         Panel panel;
 13         Label[] alabelName = new Label[3];
 14         Label[] alabelValue = new Label[3];
 15         VScrollBar[] avscroll = new VScrollBar[3];
 16 
 17         static void Main(string[] args)
 18         {
 19             Application.Run(new ColorScroll());
 20         }
 21         public ColorScroll()
 22         {
 23             Text = "Color Scroll";
 24             Color[] acolor = { Color.Red,Color.Green,Color.Blue};
 25             //以下为测试使用
 26             Console.WriteLine(acolor[0]);
 27             Console.WriteLine(acolor[1].ToString());
 28             Console.WriteLine(acolor[2].ToKnownColor());
 29             Console.WriteLine(Color.Red.ToKnownColor());
 30             Console.WriteLine((Color.Red).GetType());
 31 
 32             //Create the panel
 33             panel = new Panel();
 34             panel.Parent = this;
 35             panel.Location = new Point(0,0);
 36             panel.BackColor = Color.White;
 37 
 38             //Loop though the three colors
 39             for (int i = 0; i < 3; i++)
 40             {
 41                 alabelName[i] = new Label();
 42                 alabelName[i].Parent = panel;
 43                 alabelName[i].ForeColor = acolor[i];
 44                 alabelName[i].Text = "&" + acolor[i].ToKnownColor();
 45                 alabelName[i].TextAlign = ContentAlignment.MiddleCenter;
 46 
 47                 avscroll[i] = new VScrollBar();
 48                 avscroll[i].Parent = panel;
 49                 avscroll[i].SmallChange = 1;
 50                 avscroll[i].LargeChange = 16;
 51                 avscroll[i].Minimum = 0;
 52                 avscroll[i].Maximum = 255 + avscroll[i].LargeChange - 1;
 53                 avscroll[i].ValueChanged += new EventHandler(ColorScroll_ValueChanged);
 54                 avscroll[i].TabStop = true;
 55 
 56                 alabelValue[i] = new Label();
 57                 alabelValue[i].Parent = panel;
 58                 alabelValue[i].TextAlign = ContentAlignment.MiddleCenter;
 59             }
 60             Color color = BackColor;
 61             
 62             //Generates ValueChanged Event
 63             avscroll[0].Value = color.R;
 64             
 65             avscroll[1].Value = color.G;
 66             avscroll[2].Value = color.B;
 67 
 68             OnResize(EventArgs.Empty);
 69         }
 70 
 71         protected override void OnResize(EventArgs e)
 72         {
 73              base.OnResize(e);
 74 
 75              int cx = ClientSize.Width;
 76              int cy = ClientSize.Height;
 77              int cyFont = Font.Height;
 78 
 79              panel.Size = new Size(cx/2,cy);
 80 
 81              for (int i = 0; i < 3; i++)
 82              {
 83                  //文字标签的位置和尺寸大小
 84                  alabelName[i].Location = new Point(i * cx/6,cyFont/2);
 85                  alabelName[i].Size = new Size(cx/6,cyFont);
 86 
 87                  //滚动条的位置和尺寸大小
 88                  avscroll[i].Location = new Point((4 * i + 1) * cx / 24, 2 * cyFont);
 89                  //avscroll[i].Location = new Point(i * cx / 6, 2*cyFont);
 90                  avscroll[i].Size = new Size(cx/12,cy - 4 * cyFont);
 91 
 92                  //数字标签的位置和尺寸大小 
 93                  alabelValue[i].Location = new Point(i * cx/6,cy-3*cyFont/2);
 94                  alabelValue[i].Size = new Size(cx/6,cyFont);
 95              }
 96         }
 97 
 98         void ColorScroll_ValueChanged(object sender, EventArgs e)
 99         {
100             for (int i = 0; i < 3; i++)
101             {
102                 if ((VScrollBar)sender == avscroll[i])
103                 {
104                     alabelValue[i].Text = avscroll[i].Value.ToString();
105                 }
106             }
107             BackColor = Color.FromArgb(avscroll[0].Value,
108                                         avscroll[1].Value,
109                                         avscroll[2].Value);
110         }
111     }
112 }

上述代码中alabelName[i].Text = "&" + acolor[i].ToKnownColor();是用于在标签页中展示文字，类型是string，按照惯常思维应该使用alabelName[i].Text = "&" + acolor[i].ToString();就可以了，但是实际不是这样；

在上述代码的第27行中加入测试代码Console.WriteLine(acolor[1].ToString());

运行后如下：

显示的是Color [Green]，而不是我们期待的Green;