VB和c#取得mp3长度

<< VB.Net >>

Imports System.IO
Imports Microsoft.Win32

' API 宣告
Private Declare Function mciSendStringA Lib "Winmm.dll" _
    (ByVal lpszCommand As String, ByVal lpszReturnString As String, _
    ByVal cchReturn As Integer, ByVal hwndCallback As IntPtr) As Integer

 

Private Sub Button1_Click(ByVal s As Object, ByVal e As EventArgs) Handles Button1.Click

    MessageBox.Show(Cvt2HMS(GetMediaLen("C:\音樂欣賞\Candy Shop.mp3")))
    MessageBox.Show(Cvt2HMS(GetMediaLen("C:\音樂欣賞\國境之南.wmv")))
    MessageBox.Show(Cvt2HMS(GetMediaLen("C:\音樂欣賞\Time to say goodbye.wma")))
    MessageBox.Show(Cvt2HMS(GetMediaLen("C:\音樂欣賞\寶貝.flv")))

End Sub

 

' 取得多媒體檔案長度
Private Function GetMediaLen(ByVal File As String) As Long

    Dim key As String = "SOFTWARE\Microsoft\Windows NT\CurrentVersion\MCI Extensions"
    Dim RegKey As RegistryKey = Registry.LocalMachine.OpenSubKey(key)
    Dim FileExt As String = (Path.GetExtension(File).Replace(".", ""))
    Dim tp As String = RegKey.GetValue(FileExt, "MPEGVideo")
    RegKey.Close()

    Dim tm As New String(Chr(0), 128)
    Dim cmd As String
    cmd = "open """ & File & """ type " & tp & " alias Media"

    If mciSendStringA(cmd, vbNullString, 0, 0) = 0 Then
        If mciSendStringA("status Media length", tm, tm.Length, 0) = 0 Then
            If tm <> "" Then GetMediaLen = Convert.ToInt32(tm) \ 1000
        End If
        mciSendStringA("close Media", vbNullString, 0, 0)
    End If

End Function

 

' 轉換成時分秒
Private Function Cvt2HMS(ByVal sec As Long) As String

    Dim h, m, s As Integer
    Cvt2HMS = ""
    h = sec \ 3600
    If h > 0 Then Cvt2HMS &= h.ToString & "時"
    m = (sec Mod 3600) \ 60
    If m > 0 Then Cvt2HMS &= m.ToString & "分"
    s = (sec Mod 3600) Mod 60
    If s > 0 Then Cvt2HMS &= s.ToString & "秒"

End Function

 

<< C# >>

using System.IO;
using Microsoft.Win32;

// API 宣告
[DllImport("winmm.dll", EntryPoint = "mciSendString", CharSet = CharSet.Auto)]
public static extern int mciSendString(
    string lpstrCommand, string lpstrReturnString,
    int uReturnLength, int hwndCallback);

 

private void button1_Click(object s, EventArgs e)
{
    MessageBox.Show(GetMediaLen(@"D:\音樂欣賞\Dirty.mp3").ToString() + " Sec");
}

 

// 取得多媒體檔案長度
private long GetMediaLen(string File)
{
    long RetVal = 0;
    string key = "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\MCI Extensions";
    RegistryKey RegKey = Registry.LocalMachine.OpenSubKey(key);
    string FileExt = Path.GetExtension(File).Replace(".", "");
    string tp = RegKey.GetValue(FileExt, "MPEGVideo").ToString();
    RegKey.Close();

    string tm = new string((char)0, 128);
    if (mciSendString("open \"" + File + "\" type " + tp + " alias Media", null, 0, 0) == 0)
        {
        if (mciSendString("status Media length", tm, tm.Length, 0) == 0)
        {
            tm = tm.Trim((char)0);
            if (!string.IsNullOrEmpty(tm)) RetVal = Convert.ToInt64(tm) / 1000;
        }
        mciSendString("close Media", null, 0, 0);
    }
    return RetVal;
}