播放器02：顺序播放，用到了InvokeRequired 属性和委托(Delegate)的BeginInvoke方法

初学C#记录历程,记录心情。

UI：

                    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 OrderPlay
                    {
                        public partial class myAudioPlayer : Form
                        {

                            private bool close = false;// 关闭窗口标志位
                            private bool running = false;//线程结束标志位
                            protected List<string> playList = new List<string>();  //定义一个list来保存加进到listbox里面的文件

                             private void SaveFiles()
                            {
                                foreach (var fileName in openFileDialog.FileNames)
                                {
                                    if (playList.Contains(fileName) == true)          //不加重复的   
                                    {
                                        continue;
                                    }
                                    else
                                    {
                                        playList.Add(fileName);          //保存原始文件到playList
                                        lstPlayer.Items.Add(DeletePath(fileName));      //添加文件到listbox
                                    }
                                }
                            }


              
                            public myAudioPlayer()
                            {
                                InitializeComponent();
                                mediaPlayer.uiMode = "Full";
                            }
                                                
       
                            //双击播放列表里面的文件，播放
                            private void lstPlayer_MouseDoubleClick(object sender, MouseEventArgs e)
                            {
                              mediaPlayer.URL = playList[lstPlayer.SelectedIndex];
                              
                            }

                            private void orderPlayToolStripMenuItem_Click(object sender, EventArgs e)
                            {
                                if (!running)
                                {
                                    // 启动另一线程检测 mediaPlayer 的播放状态，循环播放列表里的歌曲
                                    running = true;
                                    Thread thread = new Thread(new ThreadStart(this.CheckStatus));
                                    thread.IsBackground = false;   //设置后台线程为false
                                    thread.Start();
                                }
                                if (lstPlayer.Items.Count == 0)
                                {
                                    MessageBox.Show("No file in List");
                                }
                            }

                            //检查线程状态,顺序播放
                            private void CheckStatus()
                            {
                                while (running && !close)
                                {
                                    try
                                    {
                                        if (mediaPlayer.playState == WMPLib.WMPPlayState.wmppsStopped && lstPlayer.Items.Count > 0)  //是否播放停止且列表有文件
                                        {
                                            if (lstPlayer.InvokeRequired)           //是否跨线程
                                            {
                                                lstPlayer.BeginInvoke(new MethodInvoker(() =>//BeginInvoke方法可以使用线程异步地执行委托所指向的方法
                                                {
                                                    SetSelectedIndex();
                                                }), null);
                                            }
                                            else
                                            {
                                                SetSelectedIndex();
                                            }

                                        }
                                                                         
                                    }
                                    catch (Exception ex)
                                    {
                                        MessageBox.Show("出错" + ex.ToString());
                                    }
                                    System.Threading.Thread.Sleep(1000);//状态检测延时1秒,加快打开歌曲的速度
                                }
                                running = false;
                                                            

                            }

                            private void SetSelectedIndex()
                            {
                                if (lstPlayer.SelectedIndex + 1 > lstPlayer.Items.Count - 1)  //是否到最下面
                                {
                                    lstPlayer.SelectedIndex = 0;      //回到第一个
                                }
                                else
                                {
                                    lstPlayer.SelectedIndex = lstPlayer.SelectedIndex + 1;   //下移
                                }
                                mediaPlayer.URL = playList[lstPlayer.SelectedIndex];   //播放
            
                            }

                            private void threadOrderPlay_FormClosing(object sender, FormClosingEventArgs e)
                            {
                                this.close = true;
                            }

                       
                       




                        }
                    }