using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.IO;
using System.Windows.Forms;

进入shell32.dll 在windows\system32下

public static string GetMediaTimeLen(string path)
{
try
{
Shell32.Shell shell = new Shell32.Shell();
//文件路径
Shell32.Folder folder = shell.NameSpace(Path.GetDirectoryName(path));
//文件名称
Shell32.FolderItem folderitem = folder.ParseName(Path.GetFileName(path));
if (Environment.OSVersion.Version.Major >= 6)
{
return folder.GetDetailsOf(folderitem, 27);
}
else
{
return folder.GetDetailsOf(folderitem, 21);
}
}
catch (Exception ex) { return null; }
}

public static int GetMediaTimeLenSecond(string path)
{
try
{
Shell32.Shell shell = new Shell32.Shell();
//文件路径
Shell32.Folder folder = shell.NameSpace(shell.NameSpace(Path.GetDirectoryName(path)));
//文件名称
Shell32.FolderItem folderitem = folder.ParseName(Path.GetFileName(path));
string len;
if (Environment.OSVersion.Version.Major >= 6)
{
len = folder.GetDetailsOf(folderitem, 27);
}
else
{
len = folder.GetDetailsOf(folderitem, 21);
}

string[] str = len.Split(new char[] { ':' });
int sum = 0;
sum = int.Parse(str[0]) * 60 * 60 + int.Parse(str[1]) * 60 + int.Parse(str[2]);

return sum;
}
catch (Exception ex) { return 0; }
}

private void button5_Click(object sender, EventArgs e)
{
string FileName = @"C:\Users\Administrator\Documents\Tencent Files\853740877\FileRecv\1.2ArcGIS体系.mp4";
MessageBox.Show(GetMediaTimeLen(FileName) + ",秒数:" + GetMediaTimeLenSecond(FileName));
}