C#中对ActiveX控件的调用

调用ActiveX控件编写播放器时,遇到了不少问题!

发现MS.NET2003中缺少对一些动态链接库的引用！
在调用ActiveX等多媒体控件时，需要用到的MediaPlayer.dll 和 AxMediaPlayer.dll需要自己生成。
首先用下面的命令为媒体播放器控件：msdxm.ocx 生成 MediaPlayer.dll 和 AxMediaPlayer.dll。
aximp c:\winnt\system32\msdxm.ocx

而通常msdxm.ocx中的ActiveX控件都未注册!
再运行regsvr32 msdxm.ocx手动注册便生成需要的动态连接库文件.
再如图2所示，在项目中添加对MediaPlayer.dll 和 AxMediaPlayer.dll的引用；
并在程序中插入：using MediaPlayer便完成了整个调用过程！

播放器如图:



源程序代码如下：

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using MediaPlayer;

namespace AdvancePlayer
{

    /// Form1 的摘要说明。
    /// </summary>
    public class Form1 : System.Windows.Forms.Form
{
        private AxMediaPlayer.AxMediaPlayer axWindowsMediaPlayer1;
        private System.Windows.Forms.OpenFileDialog openFileDialog1;
        private System.Windows.Forms.MainMenu mainMenu1;
        private System.Windows.Forms.MenuItem menuItemOpen;
        private System.Windows.Forms.MenuItem menuItemClose;
        private System.Windows.Forms.MenuItem menuItemInitSize;
        private System.Windows.Forms.MenuItem menuItemFullScreen;
        private System.Windows.Forms.MenuItem menuItemShowAudioCtrl;
        private System.Windows.Forms.MenuItem menuItemShowPositionCtrl;
        private System.Windows.Forms.MenuItem menuItemShowTrackbarCtrl;
        private System.Windows.Forms.MenuItem menuItemFile;
        private System.Windows.Forms.MenuItem menuItemVideo;
        private System.Windows.Forms.MenuItem menuItemWindow;
        
        

        /// 必需的设计器变量。
        /// </summary>
        private System.ComponentModel.Container components = null;

        public Form1()
{
            //
            // Windows 窗体设计器支持所必需的
            //
            InitializeComponent();

            //
            // TODO: 在 InitializeComponent 调用后添加任何构造函数代码
            //
        }


        /// 清理所有正在使用的资源。
        /// </summary>
        protected override void Dispose( bool disposing )
{
            if( disposing )
{
                if (components != null) 
{
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }



        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
{
            System.Resources.ResourceManager resources = new System.Resources.ResourceManager(typeof(Form1));
            this.openFileDialog1 = new System.Windows.Forms.OpenFileDialog();
            this.mainMenu1 = new System.Windows.Forms.MainMenu();
            this.menuItemFile = new System.Windows.Forms.MenuItem();
            this.menuItemOpen = new System.Windows.Forms.MenuItem();
            this.menuItemClose = new System.Windows.Forms.MenuItem();
            this.menuItemVideo = new System.Windows.Forms.MenuItem();
            this.menuItemInitSize = new System.Windows.Forms.MenuItem();
            this.menuItemFullScreen = new System.Windows.Forms.MenuItem();
            this.menuItemWindow = new System.Windows.Forms.MenuItem();
            this.menuItemShowAudioCtrl = new System.Windows.Forms.MenuItem();
            this.menuItemShowPositionCtrl = new System.Windows.Forms.MenuItem();
            this.menuItemShowTrackbarCtrl = new System.Windows.Forms.MenuItem();
            this.axWindowsMediaPlayer1 = new AxMediaPlayer.AxMediaPlayer();
            ((System.ComponentModel.ISupportInitialize)(this.axWindowsMediaPlayer1)).BeginInit();
            this.SuspendLayout();
            // 
            // openFileDialog1
            // 
            this.openFileDialog1.FileOk += new System.ComponentModel.CancelEventHandler(this.openFileDialog1_FileOk);
            // 
            // mainMenu1
            // 
{
                                                                                      this.menuItemFile,
                                                                                      this.menuItemVideo,
                                                                                      this.menuItemWindow});
            // 
            // menuItemFile
            // 
            this.menuItemFile.Index = 0;
{
                                                                                         this.menuItemOpen,
                                                                                         this.menuItemClose});
            this.menuItemFile.Shortcut = System.Windows.Forms.Shortcut.CtrlF;
            this.menuItemFile.Text = "文件(&F)";
            // 
            // menuItemOpen
            // 
            this.menuItemOpen.Index = 0;
            this.menuItemOpen.Shortcut = System.Windows.Forms.Shortcut.CtrlO;
            this.menuItemOpen.Text = "打开(&O)";
            this.menuItemOpen.Click += new System.EventHandler(this.menuItemOpen_Click);
            this.menuItemOpen.Select += new System.EventHandler(this.Form1_Load);
            // 
            // menuItemClose
            // 
            this.menuItemClose.Index = 1;
            this.menuItemClose.Shortcut = System.Windows.Forms.Shortcut.CtrlC;
            this.menuItemClose.Text = "关闭(&C)";
            this.menuItemClose.Click += new System.EventHandler(this.menuItemClose_Click);
            // 
            // menuItemVideo
            // 
            this.menuItemVideo.Index = 1;
{
                                                                                          this.menuItemInitSize,
                                                                                          this.menuItemFullScreen});
            this.menuItemVideo.Shortcut = System.Windows.Forms.Shortcut.CtrlV;
            this.menuItemVideo.Text = "视频(&V)";
            // 
            // menuItemInitSize
            // 
            this.menuItemInitSize.Index = 0;
            this.menuItemInitSize.Shortcut = System.Windows.Forms.Shortcut.CtrlI;
            this.menuItemInitSize.Text = "默认尺寸(&I)";
            this.menuItemInitSize.Click += new System.EventHandler(this.menuItemInitSize_Click);
            // 
            // menuItemFullScreen
            // 
            this.menuItemFullScreen.Index = 1;
            this.menuItemFullScreen.Shortcut = System.Windows.Forms.Shortcut.CtrlF;
            this.menuItemFullScreen.Text = "全屏(&F)";
            this.menuItemFullScreen.Click += new System.EventHandler(this.menuItemFullScreen_Click);
            // 
            // menuItemWindow
            // 
            this.menuItemWindow.Index = 2;
{
                                                                                           this.menuItemShowAudioCtrl,
                                                                                           this.menuItemShowPositionCtrl,
                                                                                           this.menuItemShowTrackbarCtrl});
            this.menuItemWindow.Shortcut = System.Windows.Forms.Shortcut.CtrlW;
            this.menuItemWindow.Text = "窗口(&W)";
            // 
            // menuItemShowAudioCtrl
            // 
            this.menuItemShowAudioCtrl.Checked = true;
            this.menuItemShowAudioCtrl.Index = 0;
            this.menuItemShowAudioCtrl.Shortcut = System.Windows.Forms.Shortcut.CtrlU;
            this.menuItemShowAudioCtrl.Text = "音频控制(&U)";
            this.menuItemShowAudioCtrl.Click += new System.EventHandler(this.menuItemShowAudioCtrl_Click);
            // 
            // menuItemShowPositionCtrl
            // 
            this.menuItemShowPositionCtrl.Checked = true;
            this.menuItemShowPositionCtrl.Index = 1;
            this.menuItemShowPositionCtrl.Shortcut = System.Windows.Forms.Shortcut.CtrlP;
            this.menuItemShowPositionCtrl.Text = "播放进度(&P)";
            this.menuItemShowPositionCtrl.Click += new System.EventHandler(this.menuItemShowPositionCtrl_Click);
            // 
            // menuItemShowTrackbarCtrl
            // 
            this.menuItemShowTrackbarCtrl.Checked = true;
            this.menuItemShowTrackbarCtrl.Index = 2;
            this.menuItemShowTrackbarCtrl.Shortcut = System.Windows.Forms.Shortcut.CtrlT;
            this.menuItemShowTrackbarCtrl.Text = "滚动条(&T)";
            this.menuItemShowTrackbarCtrl.Click += new System.EventHandler(this.menuItemShowTrackbarCtrl_Click);
            // 
            // axWindowsMediaPlayer1
            // 
            this.axWindowsMediaPlayer1.Location = new System.Drawing.Point(0, -8);
            this.axWindowsMediaPlayer1.Name = "axWindowsMediaPlayer1";
            this.axWindowsMediaPlayer1.OcxState = ((System.Windows.Forms.AxHost.State)(resources.GetObject("axWindowsMediaPlayer1.OcxState")));
            this.axWindowsMediaPlayer1.Size = new System.Drawing.Size(296, 280);
            this.axWindowsMediaPlayer1.TabIndex = 0;
            // 
            // Form1
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
            this.BackColor = System.Drawing.SystemColors.Control;
            this.ClientSize = new System.Drawing.Size(292, 273);
            this.Controls.Add(this.axWindowsMediaPlayer1);
            this.ForeColor = System.Drawing.SystemColors.ControlText;
            this.Menu = this.mainMenu1;
            this.Name = "Form1";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.Form1_Load);
            ((System.ComponentModel.ISupportInitialize)(this.axWindowsMediaPlayer1)).EndInit();
            this.ResumeLayout(false);

        }
        #endregion


        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main() 
{
            Application.Run(new Form1());
        }

        private void menuItemOpen_Click(object sender, System.EventArgs e)
{
            openFileDialog1.Filter = "视频文件(*.avi;*.wmv;*.dat;*.mpg;*.mpeg;*.mov;*.wm;*.wma)|*.avi;*.wmv;*.dat;*.mpg;*.mpeg;*.mov;*.wm;*.wma|音频文件(*.wav;*.mp3;*.snd;*.au;*.midi;*.mid)|*.wav;*.mp3;*.snd;*.au;*.midi;*.mid|所有文件(*.*)|*.*";       
            //打开的文件类型
            if(openFileDialog1.ShowDialog()==DialogResult.OK)
{
                axWindowsMediaPlayer1.FileName = openFileDialog1.FileName;
                //如果打开的是音频文件，则禁止【视频】菜单组
                if(openFileDialog1.FilterIndex == 2)
                    menuItemVideo.Enabled = false;
                else
                    menuItemVideo.Enabled = true;
            }
        
        }

        private void menuItemClose_Click(object sender, System.EventArgs e)
{
            axWindowsMediaPlayer1.FileName = null;
            menuItemVideo.Enabled = false;
        }

        private void menuItemInitSize_Click(object sender, System.EventArgs e)
{
            axWindowsMediaPlayer1.DisplaySize = MPDisplaySizeConstants.mpDefaultSize;
        }

        private void menuItemFullScreen_Click(object sender, System.EventArgs e)
{
            axWindowsMediaPlayer1.DisplaySize = MPDisplaySizeConstants.mpFullScreen;
        }

        private void menuItemShowAudioCtrl_Click(object sender, System.EventArgs e)
{
            menuItemShowAudioCtrl.Checked = !menuItemShowAudioCtrl.Checked;
            axWindowsMediaPlayer1.ShowTracker = false;
            axWindowsMediaPlayer1.ShowTracker = menuItemShowTrackbarCtrl.Checked;
            axWindowsMediaPlayer1.ShowAudioControls = menuItemShowAudioCtrl.Checked;
        }

        private void menuItemShowPositionCtrl_Click(object sender, System.EventArgs e)
{
            menuItemShowPositionCtrl.Checked = !menuItemShowPositionCtrl.Checked;
            axWindowsMediaPlayer1.ShowPositionControls = menuItemShowPositionCtrl.Checked;
        }

        private void menuItemShowTrackbarCtrl_Click(object sender, System.EventArgs e)
{
            menuItemShowTrackbarCtrl.Checked = !menuItemShowTrackbarCtrl.Checked;
            axWindowsMediaPlayer1.ShowAudioControls = false;
            axWindowsMediaPlayer1.ShowTracker = menuItemShowTrackbarCtrl.Checked;
            axWindowsMediaPlayer1.ShowAudioControls = menuItemShowAudioCtrl.Checked;
        }

        private void openFileDialog1_FileOk(object sender, System.ComponentModel.CancelEventArgs e)
{
            
            openFileDialog1.OpenFile();
        }

        private void Form1_Load(object sender, System.EventArgs e)
{
        
        }
    }
}

 
        （图2）

      如图2中选中的AxMediaPlayer和MediaPlayer既需自己生成的dll，2003系统默认中无迹可寻！他们所起的作用便是实现对ActiceX中播放器相关的函数的调用！
      所以，对于多媒体应用程序的编写，关键在于了解对ActiveX相关控件的调用过程！
     
      充分使用.NET中的控件技术，无疑是最直接和最高效的选择，这给我们提供了很大的方便，以往很多需要自己编写的函数和功能，现在都为我们封装成了各种控件，直接调用便可实现！相比往日，效率提高了不少！但其中相关的实现过程和细节还是应该多加了解才好，毕竟，只有让其工作原理烂熟于心，才能将.NET这门强大的技术运用得炉火纯青！