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;using System.Threading;namespace AppDemo{  public partial class frmMain : Form  {    public frmMain()    {      InitializeComponent();    }    /// <summary>    /// 窗體初始狀態    /// </summary>    private FormWindowState fwsPrevious;    /// <summary>    /// 懸浮窗體    /// </summary>    private frmTopMost myTopMost;    /// <summary>    /// 主窗體的Load事件    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    private void frmMain_Load(object sender, EventArgs e)    {      fwsPrevious = this.WindowState;      myTopMost = new frmTopMost(this);    }    /// <summary>    /// 主窗體的SizeChanged事件    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    private void frmMain_SizeChanged(object sender, EventArgs e)    {      if (this.WindowState == FormWindowState.Minimized)      {        myTopMost.Show();        this.ShowInTaskbar = false;      }      else if (this.WindowState != fwsPrevious)      {        fwsPrevious = this.WindowState;      }    }    /// <summary>    /// 還原窗口方法，即供懸浮窗口進行調用的。    /// </summary>    public void RestoreWindow()    {      this.WindowState = fwsPrevious;      this.ShowInTaskbar = true;    }  }}

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 AppDemo{  /// <summary>  /// 首先要設置其窗體的FormBorderStyle為None，然后設置其的TopMost為true，接下來，就是主要是三個鼠標事件的處理  /// </summary>  public partial class frmTopMost : Form  {    public frmTopMost()    {      InitializeComponent();    }    /// <summary>    /// 懸浮窗口的構造函數    /// </summary>    /// <param name="main"></param>    public frmTopMost(frmMain main)    {      InitializeComponent();      pParent = main;    }    private Point ptMouseCurrrnetPos, ptMouseNewPos, ptFormPos, ptFormNewPos;    private bool blnMouseDown = false;    private frmMain pParent;    /// <summary>    /// 懸浮窗口的Load事件    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    private void frmTopMost_Load(object sender, EventArgs e)    {      this.Show();      this.Top = 100;      this.Left = Screen.PrimaryScreen.Bounds.Width - 100;      this.Width = 80;      this.Height = 80;    }    private void frmTopMost_MouseMove(object sender, MouseEventArgs e)    {      if (blnMouseDown)      {        ptMouseNewPos = Control.MousePosition;        ptFormNewPos.X = ptMouseNewPos.X - ptMouseCurrrnetPos.X + ptFormPos.X;        ptFormNewPos.Y = ptMouseNewPos.Y - ptMouseCurrrnetPos.Y + ptFormPos.Y;        Location = ptFormNewPos;        ptFormPos = ptFormNewPos;        ptMouseCurrrnetPos = ptMouseNewPos;      }    }    private void frmTopMost_MouseDown(object sender, MouseEventArgs e)    {      if (e.Button == MouseButtons.Left)      {        blnMouseDown = true;        ptMouseCurrrnetPos = Control.MousePosition;        ptFormPos = Location;      }    }    private void frmTopMost_MouseUp(object sender, MouseEventArgs e)    {      if (e.Button == MouseButtons.Left)        blnMouseDown = false;    }    /// <summary>    /// 雙擊懸浮窗體，進行恢復主窗體。    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    private void frmTopMost_MouseDoubleClick(object sender, MouseEventArgs e)    {      SwitchToMain();    }    private void SwitchToMain()    {      pParent.RestoreWindow();      this.Hide();    }  }}