程序最小化时，在桌面显示一个悬浮窗——仿播放器

功能—效果展示

在主程序最小化时，希望显示一个浮窗（支持拖拽），显示当前的运行信息，功能如下：

点击最小化，主界面关闭，浮窗出现点击浮窗主界面按钮，浮窗关闭，主界面出现切歌，可根据具体业务逻辑添加内容退出，退出当前程序

浮窗代码

新建一个Winform(.NetFramework)项目，添加一个窗体FloatingWindow.cs

代码如下：

FloatingForm.Designer.cs

 partial class FloatingForm
 {
     /// <summary>
     /// Required designer variable.
     /// </summary>
     private System.ComponentModel.IContainer components = null;

     /// <summary>
     /// Clean up any resources being used.
     /// </summary>
     /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
     protected override void Dispose(bool disposing)
     {
         if (disposing && (components != null))
         {
             components.Dispose();
         }
         base.Dispose(disposing);
     }

     #region Windows Form Designer generated code

     /// <summary>
     /// Required method for Designer support - do not modify
     /// the contents of this method with the code editor.
     /// </summary>
     private void InitializeComponent()
     {
         this.mainPanel = new System.Windows.Forms.Panel();
         this.exitButton = new System.Windows.Forms.Button();
         this.nextMusic = new System.Windows.Forms.Button();
         this.mainFormButton = new System.Windows.Forms.Button();
         this.lbl_music = new System.Windows.Forms.Label();
         this.mainPanel.SuspendLayout();
         this.SuspendLayout();
         // 
         // mainPanel
         // 
         this.mainPanel.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(120)))), ((int)(((byte)(230)))), ((int)(((byte)(240)))), ((int)(((byte)(250)))));
         this.mainPanel.Controls.Add(this.exitButton);
         this.mainPanel.Controls.Add(this.nextMusic);
         this.mainPanel.Controls.Add(this.mainFormButton);
         this.mainPanel.Controls.Add(this.lbl_music);
         this.mainPanel.Dock = System.Windows.Forms.DockStyle.Fill;
         this.mainPanel.Location = new System.Drawing.Point(6, 7);
         this.mainPanel.Margin = new System.Windows.Forms.Padding(4);
         this.mainPanel.Name = "mainPanel";
         this.mainPanel.Size = new System.Drawing.Size(361, 132);
         this.mainPanel.TabIndex = 0;
         this.mainPanel.MouseDown += new System.Windows.Forms.MouseEventHandler(this.panel_MouseDown);
         this.mainPanel.MouseMove += new System.Windows.Forms.MouseEventHandler(this.panel_MouseMove);
         // 
         // exitButton
         // 
         this.exitButton.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(220)))), ((int)(((byte)(53)))), ((int)(((byte)(69)))));
         this.exitButton.FlatAppearance.BorderSize = 0;
         this.exitButton.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
         this.exitButton.ForeColor = System.Drawing.Color.White;
         this.exitButton.Location = new System.Drawing.Point(263, 81);
         this.exitButton.Name = "exitButton";
         this.exitButton.Size = new System.Drawing.Size(75, 29);
         this.exitButton.TabIndex = 3;
         this.exitButton.Text = "退出";
         this.exitButton.UseVisualStyleBackColor = false;
         this.exitButton.Click += new System.EventHandler(this.ExitButton_Click);
         // 
         // nextMusic
         // 
         this.nextMusic.BackColor = System.Drawing.Color.ForestGreen;
         this.nextMusic.FlatAppearance.BorderSize = 0;
         this.nextMusic.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
         this.nextMusic.ForeColor = System.Drawing.Color.White;
         this.nextMusic.Location = new System.Drawing.Point(133, 81);
         this.nextMusic.Name = "nextMusic";
         this.nextMusic.Size = new System.Drawing.Size(94, 29);
         this.nextMusic.TabIndex = 2;
         this.nextMusic.Text = "切歌";
         this.nextMusic.UseVisualStyleBackColor = false;
         this.nextMusic.Click += new System.EventHandler(this.ChangeMusicButton_Click);
         // 
         // mainFormButton
         // 
         this.mainFormButton.BackColor = System.Drawing.Color.SteelBlue;
         this.mainFormButton.FlatAppearance.BorderSize = 0;
         this.mainFormButton.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
         this.mainFormButton.ForeColor = System.Drawing.Color.White;
         this.mainFormButton.Location = new System.Drawing.Point(21, 81);
         this.mainFormButton.Name = "mainFormButton";
         this.mainFormButton.Size = new System.Drawing.Size(75, 29);
         this.mainFormButton.TabIndex = 1;
         this.mainFormButton.Text = "主界面";
         this.mainFormButton.UseVisualStyleBackColor = false;
         this.mainFormButton.Click += new System.EventHandler(this.MainFormButton_Click);
         // 
         // lbl_music
         // 
         this.lbl_music.BackColor = System.Drawing.Color.White;
         this.lbl_music.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
         this.lbl_music.Font = new System.Drawing.Font("微软雅黑", 9F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
         this.lbl_music.Location = new System.Drawing.Point(21, 21);
         this.lbl_music.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0);
         this.lbl_music.Name = "lbl_music";
         this.lbl_music.Size = new System.Drawing.Size(317, 40);
         this.lbl_music.TabIndex = 0;
         this.lbl_music.Text = "孤勇者——陈奕迅";
         this.lbl_music.TextAlign = System.Drawing.ContentAlignment.MiddleCenter;
         // 
         // FloatingWindow
         // 
         this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 17F);
         this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
         this.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(128)))), ((int)(((byte)(128)))), ((int)(((byte)(255)))));
         this.BackgroundImageLayout = System.Windows.Forms.ImageLayout.Stretch;
         this.ClientSize = new System.Drawing.Size(373, 146);
         this.Controls.Add(this.mainPanel);
         this.Font = new System.Drawing.Font("微软雅黑", 9F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
         this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
         this.Margin = new System.Windows.Forms.Padding(4);
         this.Name = "FloatingWindow";
         this.Padding = new System.Windows.Forms.Padding(6, 7, 6, 7);
         this.ShowInTaskbar = false;
         this.StartPosition = System.Windows.Forms.FormStartPosition.Manual;
         this.Text = "FloatingWindow";
         this.TopMost = true;
         this.mainPanel.ResumeLayout(false);
         this.ResumeLayout(false);

     }

     #endregion

     private System.Windows.Forms.Panel mainPanel;
     private System.Windows.Forms.Label lbl_music;
     private System.Windows.Forms.Button mainFormButton;
     private System.Windows.Forms.Button exitButton;
     private System.Windows.Forms.Button nextMusic;
 }

FloatingForm.cs

public partial class FloatingForm: Form
{
    // Windows API 用于设置窗体圆角
    [DllImport("Gdi32.dll", EntryPoint = "CreateRoundRectRgn")]
    private static extern IntPtr CreateRoundRectRgn(
        int nLeftRect, int nTopRect, int nRightRect, int nBottomRect,
        int nWidthEllipse, int nHeightEllipse);
    public FloatingWindow()
    {
        InitializeComponent();
    }
    // 主窗体引用
    private MainForm mainForm;
    public FloatingWindow(MainForm mainForm)
    {
        InitializeComponent();

        // 保存主窗体引用
        this.mainForm = mainForm;
        // 设置圆角
        this.Region = Region.FromHrgn(CreateRoundRectRgn(0, 0, Width, Height, 20, 20));

        // 初始位置设为屏幕右下角
        Screen screen = Screen.PrimaryScreen;
        this.Location = new Point(
            screen.WorkingArea.Width - this.Width - 20,
            screen.WorkingArea.Height - this.Height - 100
        );
    }


    // 按钮点击事件处理
    private void MainFormButton_Click(object sender, EventArgs e)
    {
        if (mainForm != null)
        {
            // 显示主窗体并恢复正常状态
            mainForm.Show();
            mainForm.WindowState = FormWindowState.Normal;

            // 隐藏悬浮窗
            this.Hide();
        }
    }
    /// <summary>
    /// 退出界面
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void ExitButton_Click(object sender, EventArgs e)
    {
        // 确认退出
        if (MessageBox.Show("确定要退出程序吗？", "退出确认",
            MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
        {
            // 关闭主窗体
            if (mainForm != null)
            {
                mainForm.Close();
            }
            // 关闭悬浮窗
            this.Close();
            // 退出应用程序
            Application.Exit();
        }
    }

    #region 无边框拖拽

    private Point mPoint;

    private void panel_MouseDown(object sender, MouseEventArgs e)
    {
        mPoint = new Point(e.X, e.Y);
    }

    private void panel_MouseMove(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            this.Location = new Point(this.Location.X + e.X - mPoint.X, this.Location.Y + e.Y - mPoint.Y);
        }
    }

    #endregion

    /// <summary>
    /// 切换歌曲
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void ChangeMusicButton_Click(object sender, EventArgs e)
    {

    }
}

主程序代码

MainForm.Design.cs

    partial class MainForm
    {
        /// <summary>
        /// 必需的设计器变量。
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// 清理所有正在使用的资源。
        /// </summary>
        /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows 窗体设计器生成的代码

        /// <summary>
        /// 设计器支持所需的方法 - 不要修改
        /// 使用代码编辑器修改此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {
            this.label1 = new System.Windows.Forms.Label();
            this.SuspendLayout();
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.Font = new System.Drawing.Font("宋体", 18F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
            this.label1.Location = new System.Drawing.Point(278, 89);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(135, 24);
            this.label1.TabIndex = 0;
            this.label1.Text = "主程序界面";
            // 
            // MainForm
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(688, 281);
            this.Controls.Add(this.label1);
            this.Name = "MainForm";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.frmMain_Load);
            this.SizeChanged += new System.EventHandler(this.frmMain_SizeChanged);
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.Label label1;
    }

MainForm.cs

public partial class MainForm : Form
{
    public MainForm()
    {
        InitializeComponent();
    }
    /// <summary>
    /// 窗体初始状态
    /// </summary>
    private FormWindowState fwsPrevious;
    /// <summary>
    /// 悬浮窗体
    /// </summary>
    private FloatingForm floatingWindow;
    /// <summary>
    /// 主窗体的Load事件
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void frmMain_Load(object sender, EventArgs e)
    {
        fwsPrevious = this.WindowState;
        floatingWindow = new FloatingForm(this);
    }
    /// <summary>
    /// 主窗体的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)
        {
            // 隐藏主窗体
            this.Hide();
            this.ShowInTaskbar = false;
            // 显示悬浮窗
            if (floatingWindow != null && !floatingWindow.Visible)
            {
                floatingWindow.Show();
            }
        }
        else if (this.WindowState != fwsPrevious)
        {
            fwsPrevious = this.WindowState;
        }
    }

    /// <summary>
    /// 还原窗口方法，即供悬浮窗口进行调用的。
    /// </summary>
    public void RestoreWindow()
    {
        this.WindowState = fwsPrevious;
        this.ShowInTaskbar = true;
    }
}