如何用C#做一个悬浮窗口程序

首先是主窗体部分，即要判断窗体的状态来决定是否显示悬浮窗口。

局部成员声明：

    private FormWindowState fwsPrevious;
    private frmTopMost myTopMost;
 
主窗体的Load事件：

    private void frmMain_Load(object sender, System.EventArgs e)
    {
        // Save window state
        fwsPrevious = this.WindowState;
 
        // Create top most window
        myTopMost = new frmTopMost( this );
    }
   
    主窗体的SizeChanged事件：
    private void frmMain_SizeChanged(object sender, System.EventArgs e)
    {
        if( this.WindowState == FormWindowState.Minimized )
        {
            // Window minimized
            // Show top most window
            myTopMost.Show();
            this.ShowInTaskbar = false;
        }
        else if( this.WindowState != fwsPrevious )
        {
            // Save current window state
            fwsPrevious = this.WindowState;
        }
    }
 
       然后，就是还原窗口方法，即供悬浮窗口进行调用的。

    /// <summary>
    /// Restore window state
    /// </summary>
    public void RestoreWindow()
    {
        this.WindowState = fwsPrevious;
        this.ShowInTaskbar = true;
    }
 
       下来就是悬浮窗口部分代码，首先要设置其窗体的FormBorderStyle为None，然后设置其的TopMost为true，接下来，就是主要是三个鼠标事件的处理，以下，具体说明如何实现的。

       局部成员声明。

    private Point ptMouseCurrrnetPos, ptMouseNewPos,
        ptFormPos, ptFormNewPos;
    private bool blnMouseDown=false;
    private frmMain pParent;
 
       悬浮窗口的构造函数。

    public frmTopMost( frmMain pMain )
    {
        //
        // Required for Windows Form Designer support
        //
        InitializeComponent();
 
        // Init main window object
        pParent = pMain;
    }
 
    悬浮窗口的Load事件。
    private void frmTopMost_Load(object sender, System.EventArgs e)
    {
        this.Show();
 
        // Init window size and position
        this.Top = 100;
        this.Left = Screen.PrimaryScreen.Bounds.Width - 100;
        this.Width = 80;
        this.Height = 80;
    }
 
       主要的三个鼠标事件，即MouseDown、 MouseMove、 MouseUp三个事件。

    private void frmTopMost_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
    {
        if( blnMouseDown )
        {
            //Get the current position of the mouse in the screen
            ptMouseNewPos = Control.MousePosition;
 
            //Set window position
            ptFormNewPos.X = ptMouseNewPos.X - ptMouseCurrrnetPos.X + ptFormPos.X;
            ptFormNewPos.Y = ptMouseNewPos.Y - ptMouseCurrrnetPos.Y + ptFormPos.Y;
 
            //Save window position
            Location = ptFormNewPos;
            ptFormPos = ptFormNewPos;
 
            //Save mouse position
            ptMouseCurrrnetPos = ptMouseNewPos;
        }      
    }
 
    private void frmTopMost_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
    {
        if(e.Button==MouseButtons.Left)
        {
            blnMouseDown = true;
 
            // Save window position and mouse position
            ptMouseCurrrnetPos = Control.MousePosition;
            ptFormPos = Location;
        }
    }
 
    private void frmTopMost_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
    {
        if( e.Button == MouseButtons.Left)
            //Return back signal
            blnMouseDown = false;
    }
 
    然后就是双击悬浮窗体，进行恢复主窗体。
    private void frmTopMost_DoubleClick(object sender, System.EventArgs e)
    {
        SwitchToMain();
    }
 
    private void SwitchToMain()
    {
        //Change main window status here
        pParent.RestoreWindow();
        //Hide top most window
        this.Hide();
    }
 
    此外，还可以给悬浮窗口添加ContextMenu，来辅助操作，这里就不细说了。
    private System.Windows.Forms.ContextMenu mnuPopup;
    private System.Windows.Forms.MenuItem mnuMainWindow;
    private System.Windows.Forms.MenuItem mnuExit;
    private void mnuMainWindow_Click(object sender, System.EventArgs e)
    {
        SwitchToMain();
    }
 
    private void mnuExit_Click(object sender, System.EventArgs e)
    {
        Application.Exit();
    }

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/knight94/archive/2006/04/14/663089.aspx