一个关于工具条可以移动和在四周停留的测试

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace qi
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        bool flag=false;
        bool ok = false;
        int fangshi = 0;
        Graphics mygf;
        Pen mypen = new Pen(Color.Red);
        Color mycl = new Color();
        int width, height;
        private void Form1_MouseMove(object sender, MouseEventArgs e)
        {
            if (flag)
            {
                mygf.Clear(mycl);
                mygf.DrawRectangle(mypen, e.X - width, e.Y - 5, width, height);
                if (e.X < 20 && e.Y > 20 && e.Y < (this.Size.Height - 20))
                {
                    mygf.Clear(mycl);
                    mygf.DrawRectangle(mypen, 0, 0, 20, this.Size.Height);
                    fangshi = 1;
                }
                else if (e.Y < 20 && e.X < (this.Size.Width - 20))
                {
                    mygf.Clear(mycl);
                    mygf.DrawRectangle(mypen, 0, 0, this.Size.Width, 20);
                    fangshi = 2;
                }

                else if (e.Y < (this.Size.Height - 20) && e.X > (this.Size.Width - 40))
                {
                    mygf.Clear(mycl);
                    mygf.DrawRectangle(mypen, this.Size.Width - 35, 0, 30, this.Size.Height);
                    fangshi = 3;
                }
                else if (e.Y > (this.Size.Height - 55))
                {
                    mygf.Clear(mycl);
                    mygf.DrawRectangle(mypen, 0, (this.Size.Height - 55), this.Size.Width, 20);
                    fangshi = 4;
                }
                else
                    fangshi = 0;
                
            }
        }

        private void toolStrip1_MouseDown(object sender, MouseEventArgs e)
        {
            toolStrip1.Visible = false;
            flag = true;
        }

        private void Form1_MouseUp(object sender, MouseEventArgs e)
        {
            if (flag)
            {
                toolStrip1.Location = new Point(e.X - width, e.Y - 5);

                switch (fangshi)
                {
                    case 0:
                        toolStrip1.Dock = DockStyle.None;
                        break;
                    case 1:
                        toolStrip1.Dock = DockStyle.Left;
                        break;
                    case 2:
                        toolStrip1.Dock = DockStyle.Top;
                        break;
                    case 3:
                        toolStrip1.Dock = DockStyle.Right;
                        break;
                    case 4:
                        toolStrip1.Dock = DockStyle.Bottom;
                        break;
                }
            }
            toolStrip1.Visible = true;
            mygf.Clear(mycl);
            flag = false;
            fangshi = 0;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            mycl = this.BackColor;
            mygf = this.CreateGraphics();
            width = toolStrip1.Size.Width;
            height = toolStrip1.Size.Height;
        }
    }
}