C# Signature:

[DllImport("winmm.dll")]
static extern Int32 mciSendString(string command, StringBuilder buffer, int bufferSize, IntPtr hwndCallback);

VB.NET Signature:

<DllImport("winmm.dll")> _
Private Shared Function mciSendString(ByVal command As String, ByVal buffer As StringBuilder, ByVal bufferSize As Integer, ByVal hwndCallback As IntPtr) As Integer
End Function

VB Signature:

Declare Ansi Function mciSendString Lib "winmm.dll" Alias "mciSendStringA" (ByVal command As String, ByRef buffer As StringBuilder, ByVal bufferSize As Integer, ByVal hWndCallback As IntPtr) As Integer

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code

C#

// Open CD-ROM Drive Door
public void OpenCD()
{
    IntPtr ptr = IntPtr.Zero;
    StringBuilder returnstring = new StringBuilder();
    mciSendString("set CDAudio door open", returnstring,127, IntPtr.Zero);
}

// Open Media File
string sCommand = "open \"" + strFilePath + "\" type mpegvideo alias MediaFile";
mciSendString(sCommand, null, 0, 0);

// Play the Media File
sCommand = "play MediaFile notify";
// _frmObject is your form that will handle the notification messages
mciSendString(sCommand, null, 0, _frmObject.Handle.ToInt64());

// Declare the notify constant
public const int MM_MCINOTIFY = 953;

// Override the WndProc function in the form
protected override void WndProc(ref Message m)
{
    if (m.Msg == MM_MCINOTIFY)
    {
        // The file is done playing, do whatever
    }

    base.WndProc(ref m);
}

Or try something like that:

[DllImport("winmm.dll")]
static extern Int32 mciSendString(string command, string buffer, int bufferSize, IntPtr hwndCallback);

private void EjectCdCommand()
{
     string rt = "";
     mciSendString("set CDAudio door open", rt, 127, IntPtr.Zero);
}

private void CloseCdCommand()
{
     string rt = "";
     mciSendString("set CDAudio door closed", rt, 127, IntPtr.Zero);
}

VB.NET

' Open CD-ROM Drive Door
Public Sub OpenCDDoor()
     Dim returnstring As StringBuilder = New StringBuilder()
     mciSendString("set CDAudio door open", returnstring, 127, IntPtr.Zero)
     MsgBox(returnstring)
End Sub

' Declare the notify constant
Public Const MM_MCINOTIFY As Integer = 953

' Open and play a media file
Public Sub OpenMediaFile(ByVal strFilePath As String)
     ' Open the media file
     Dim sCommand As String = "open """ + strFilePath + """ type waveaudio alias MediaFile"
     mciSendString(sCommand, Nothing, 0, IntPtr.Zero)

     ' It's is assumed this function is in a Form so Me points to the current instance of the form
     sCommand = "play MediaFile notify"
     mciSendString(sCommand, Nothing, 0, Me.Handle.ToInt64())
End Sub

' Override the WndProc function which is called when the play function ends
Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
     If m.Msg = MM_MCINOTIFY Then
     ' The file is done playing, do whatever is necessary at this point
     MsgBox("Done playing.")
     End If
     MyBase.WndProc(m)
End Sub

Alternative Managed API:

Do you know one? Please contribute it!

Please edit this page!

Do you have...

• helpful tips or sample code to share for using this API in managed code?
• corrections to the existing content?
• variations of the signature you want to share?
• additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).