detectSoundlevel-spike/sourceCode/trunk/Code/CoreAudio/Interfaces/IMMDevice.cs

// -----------------------------------------
// SoundScribe (TM) and related software.
// 
// Copyright (C) 2007-2011 Vannatech
// http://www.vannatech.com
// All rights reserved.
// 
// This source code is subject to the MIT License.
// http://www.opensource.org/licenses/mit-license.php
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
// -----------------------------------------

using System;
using System.Runtime.InteropServices;
using Vannatech.CoreAudio.Constants;
using Vannatech.CoreAudio.Externals;

namespace Vannatech.CoreAudio.Interfaces
{
    /// <summary>
    /// Represents an audio device.
    /// </summary>
    /// <remarks>
    /// MSDN Reference: http://msdn.microsoft.com/en-us/library/dd371395.aspx
    /// </remarks>
    public partial interface IMMDevice
    {
        /// <summary>
        /// Creates a COM object with the specified interface.
        /// </summary>
        /// <param name="interfaceId">The interface identifier.</param>
		/// <param name="classContext">The execution context, defined by the COM CLSCTX enumeration.</param>
        /// <param name="activationParams">Set to NULL to activate Core Audio APIs.</param>
		/// <param name="instancePtr">The address of the interface instance specified by parameter IID.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int Activate(
			[In] [MarshalAs(UnmanagedType.LPStruct)] Guid interfaceId,
            [In] [MarshalAs(UnmanagedType.U4)] UInt32 classContext,
            [In, Optional] IntPtr activationParams, // TODO: Update to use PROPVARIANT and test properly.
			[Out] [MarshalAs(UnmanagedType.IUnknown)] out object instancePtr);

        /// <summary>
        /// Gets an interface to the device's property store.
        /// </summary>
        /// <param name="accessMode">The <see cref="STGM"/> constant that indicates the storage mode.</param>
        /// <param name="properties">The device's property store.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        /// <remarks>
        /// Note that a client which is not running as administrator is restricted to read-only access.
        /// </remarks>
        [PreserveSig]
        int OpenPropertyStore(
			[In] [MarshalAs(UnmanagedType.U4)] UInt32 accessMode,
            [Out] [MarshalAs(UnmanagedType.Interface)] out IPropertyStore properties);

        /// <summary>
        /// Retrieves an endpoint ID string that identifies the audio endpoint device.
        /// </summary>
        /// <param name="strId">The endpoint device ID.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int GetId(
            [Out] [MarshalAs(UnmanagedType.LPWStr)] out string strId);

        /// <summary>
        /// Gets the current state of the device.
        /// </summary>
		/// <param name="deviceState">The <see cref="DEVICE_STATE_XXX"/> constant that indicates the current state.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int GetState(
			[Out] [MarshalAs(UnmanagedType.U4)] out UInt32 deviceState);
    }
}