通过C#检测耳机是否插入
Detect if headphones are plugged in or not via C#
没有示例如何通过 C# 检测耳机是否插入。
我想应该是一些事件...
使用 WMI 有意义吗？
ManagementObjectSearcher searcher = new ManagementObjectSearcher("root\cimv2",
"SELECT * FROM Win32_SoundDevice");
foreach (ManagementObject queryObj in searcher.Get())
{
Console.WriteLine("-----------------------------------");
Console.WriteLine("Win32_SoundDevice instance");
Console.WriteLine("-----------------------------------");
Console.WriteLine("StatusInfo: {0}", queryObj["StatusInfo"]);
}
有人愿意提供吗？
谢谢！
可以使用 IMMDeviceEnumerator::RegisterEndpointNotificationCallback 方法检测此类更改。
如果您想在 C# 中处理此问题，您将需要一个已由 Akos Mattiassich 实现的托管包装器。你可以在这里找到一个完整的例子：Managed Wrapper around MMAudioDeviceApi
他说：
The program can play test sound on selected devices and it updates the list automatically on changes eg. through the control panel or in case of plugging new device physically.
我不建议您自己使用 COM+ API。
Install-Package NAudio
您应该能够枚举具有 plugged/unplugged 状态的音频设备，如下所示：
var enumerator = new NAudio.CoreAudioApi.MMDeviceEnumerator();
// Allows you to enumerate rendering devices in certain states
var endpoints = enumerator.EnumerateAudioEndPoints(
DataFlow.Render,
DeviceState.Unplugged | DeviceState.Active);
foreach (var endpoint in endpoints)
{
Console.WriteLine("{0} - {1}", endpoint.DeviceFriendlyName, endpoint.State);
}
// Aswell as hook to the actual event
enumerator.RegisterEndpointNotificationCallback(new NotificationClient());
其中NotificationClient实现如下：
class NotificationClient : NAudio.CoreAudioApi.Interfaces.IMMNotificationClient
{
void IMMNotificationClient.OnDeviceStateChanged(string deviceId, DeviceState newState)
{
Console.WriteLine("OnDeviceStateChanged\n Device Id -->{0} : Device State {1}", deviceId, newState);
}
void IMMNotificationClient.OnDeviceAdded(string pwstrDeviceId) { }
void IMMNotificationClient.OnDeviceRemoved(string deviceId) { }
void IMMNotificationClient.OnDefaultDeviceChanged(DataFlow flow, Role role, string defaultDeviceId) { }
void IMMNotificationClient.OnPropertyValueChanged(string pwstrDeviceId, PropertyKey key) { }
}
应该产生类似的结果：
我认为它在上面的屏幕截图中检测到两次 plugging/unplugging 的原因是因为在 Macbook 上他们使用一个插孔用于麦克风和耳机。
下面是一个（最小的）Windows 表单应用程序示例，它基于 IMMNotificationClient interface，不需要任何第三方库。
只要多媒体设备 plugged/unplugged，您就会收到通知。然后您可以查看设备属性并采取适当的措施。您还可以枚举现有设备并检查耳机是否已插入（请参阅 IsConnected 属性）。
创建 COM 互操作
请注意，示例代码包含相关 COM 对象的定义。在生产中，我可能会为底层 mmdevapi.dll 创建一个 COM 互操作程序集。您可以首先从头文件创建类型库（Windows 需要安装 SDK）：
midl /out c:\tmp /header "C:\Program Files (x86)\Windows Kits.1\Include\um\mmdeviceapi.h" "C:\Program Files (x86)\Windows Kits.1\Include\um\mmdeviceapi.idl"
然后您需要使用 tlbimp.exe:
从类型库生成互操作程序集
tlbimp /out:MMDevAPI.Interop.dll mmdeviceapi.tlb
MultiMediaNotificationListener 示例
using System;
using System.Runtime.InteropServices;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Windows.Forms;
namespace MultiMediaNotificationListenerSample
{
class MainWindow : Form
{
[STAThread]
private static void Main(string[] args)
{
using (var notificationClient = new MultiMediaNotificationListener())
{
Trace.WriteLine(string.Format("Headphone is {0}connected", notificationClient.IsConnected ? "": "not "));
Application.Run(new MainWindow());
}
}
}
class MultiMediaNotificationListener : IMMNotificationClient, IDisposable
{
private readonly IMMDeviceEnumerator _deviceEnumerator;
public MultiMediaNotificationListener()
{
if (Environment.OSVersion.Version.Major < 6)
{
throw new NotSupportedException("This functionality is only supported on Windows Vista or newer.");
}
_deviceEnumerator = (IMMDeviceEnumerator)new MMDeviceEnumerator();
_deviceEnumerator.RegisterEndpointNotificationCallback(this);
}
~MultiMediaNotificationListener()
{
Dispose(false);
}
public bool IsConnected
{
get
{
IMMDeviceCollection deviceCollection;
_deviceEnumerator.EnumAudioEndpoints(EDataFlow.eRender, (uint)DeviceState.DEVICE_STATE_ACTIVE, out deviceCollection);
uint deviceCount = 0;
deviceCollection.GetCount(out deviceCount);
for (uint i = 0; i < deviceCount; i++)
{
IMMDevice device;
deviceCollection.Item(i, out device);
IPropertyStore propertyStore;
device.OpenPropertyStore((uint)STGM.STGM_READ, out propertyStore);
PROPVARIANT property;
propertyStore.GetValue(ref PropertyKey.PKEY_Device_DeviceDesc, out property);
var value = (string)property.Value;
Marshal.ReleaseComObject(propertyStore);
Marshal.ReleaseComObject(device);
if (value == "Headphones")
{
return true;
}
}
Marshal.ReleaseComObject(deviceCollection);
return false;
}
}
public void OnDefaultDeviceChanged(EDataFlow dataFlow, ERole deviceRole, string pwstrDefaultDeviceId)
{
}
public void OnDeviceStateChanged(string pwstrDeviceId, uint dwNewState)
{
IMMDevice device;
_deviceEnumerator.GetDevice(pwstrDeviceId, out device);
IPropertyStore propertyStore;
device.OpenPropertyStore((uint)STGM.STGM_READ, out propertyStore);
Trace.WriteLine(string.Format("OnDeviceStateChanged:\n Device Id {0}\tDevice State {1}", pwstrDeviceId, (DeviceState)dwNewState));
var properties = PropertyKey.GetPropertyKeys()
.Select(
propertyKey =>
{
PROPVARIANT property;
propertyStore.GetValue(ref propertyKey, out property);
return new { Key = PropertyKey.GetKeyName(propertyKey), Value = property.Value };
})
.Where(@t => @t.Value != null);
foreach (var property in properties)
{
Trace.WriteLine(string.Format(" {0}\t{1}", property.Key, property.Value));
}
Marshal.ReleaseComObject(propertyStore);
Marshal.ReleaseComObject(device);
}
public void OnDeviceAdded(string deviceId)
{
}
public void OnDeviceRemoved(string deviceId)
{
}
public void OnPropertyValueChanged(string pwstrDeviceId, PropertyKey key)
{
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
private void Dispose(bool disposing)
{
_deviceEnumerator.UnregisterEndpointNotificationCallback(this);
Marshal.ReleaseComObject(_deviceEnumerator);
}
}
public enum STGM : uint
{
STGM_READ = 0x0,
STGM_WRITE = 0x1,
STGM_READWRITE = 0x2
}
public enum DeviceState
{
DEVICE_STATE_ACTIVE = 0x00000001,
DEVICE_STATE_DISABLED = 0x00000002,
DEVICE_STATE_NOTPRESENT = 0x00000004,
DEVICE_STATE_UNPLUGGED = 0x00000008,
DEVICE_STATEMASK_ALL = 0x0000000f
}
[ComImport]
[Guid("BCDE0395-E52F-467C-8E3D-C4579291692E")]
internal class MMDeviceEnumerator
{
}
public enum EDataFlow
{
eRender,
eCapture,
eAll,
EDataFlow_enum_count
}
public enum ERole
{
eConsole,
eMultimedia,
eCommunications,
ERole_enum_count
}
[Guid("0BD7A1BE-7A1A-44DB-8397-CC5392387B5E"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), TypeLibType(TypeLibTypeFlags.FNonExtensible)]
[ComImport]
public interface IMMDeviceCollection
{
[MethodImpl(MethodImplOptions.InternalCall)]
void GetCount(out uint pcDevices);
[MethodImpl(MethodImplOptions.InternalCall)]
void Item([In] uint nDevice, [MarshalAs(UnmanagedType.Interface)] out IMMDevice ppDevice);
}
[Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), TypeLibType(TypeLibTypeFlags.FNonExtensible)]
[ComImport]
public interface IMMDeviceEnumerator
{
[MethodImpl(MethodImplOptions.InternalCall)]
void EnumAudioEndpoints([ComAliasName("MMDevAPI.Interop.EDataFlow")] [In] EDataFlow dataFlow, [In] uint dwStateMask, [MarshalAs(UnmanagedType.Interface)] out IMMDeviceCollection ppDevices);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetDefaultAudioEndpoint([ComAliasName("MMDevAPI.Interop.EDataFlow")] [In] EDataFlow dataFlow, [ComAliasName("MMDevAPI.Interop.ERole")] [In] ERole role, [MarshalAs(UnmanagedType.Interface)] out IMMDevice ppEndpoint);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetDevice([MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrId, [MarshalAs(UnmanagedType.Interface)] out IMMDevice ppDevice);
[MethodImpl(MethodImplOptions.InternalCall)]
void RegisterEndpointNotificationCallback([MarshalAs(UnmanagedType.Interface)] [In] IMMNotificationClient pClient);
[MethodImpl(MethodImplOptions.InternalCall)]
void UnregisterEndpointNotificationCallback([MarshalAs(UnmanagedType.Interface)] [In] IMMNotificationClient pClient);
}
[Guid("D666063F-1587-4E43-81F1-B948E807363F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), TypeLibType(TypeLibTypeFlags.FNonExtensible)]
[ComImport]
public interface IMMDevice
{
[MethodImpl(MethodImplOptions.InternalCall)]
void Activate([In] ref Guid iid, [In] uint dwClsCtx, [In] IntPtr pActivationParams, [MarshalAs(UnmanagedType.IUnknown)] out object ppInterface);
[MethodImpl(MethodImplOptions.InternalCall)]
void OpenPropertyStore([In] uint stgmAccess, [MarshalAs(UnmanagedType.Interface)] out IPropertyStore ppProperties);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetId([MarshalAs(UnmanagedType.LPWStr)] out string ppstrId);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetState(out uint pdwState);
}
[Guid("7991EEC9-7E89-4D85-8390-6C703CEC60C0"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), TypeLibType(TypeLibTypeFlags.FNonExtensible)]
[ComImport]
public interface IMMNotificationClient
{
[MethodImpl(MethodImplOptions.InternalCall)]
void OnDeviceStateChanged([MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrDeviceId, [In] uint dwNewState);
[MethodImpl(MethodImplOptions.InternalCall)]
void OnDeviceAdded([MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrDeviceId);
[MethodImpl(MethodImplOptions.InternalCall)]
void OnDeviceRemoved([MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrDeviceId);
[MethodImpl(MethodImplOptions.InternalCall)]
void OnDefaultDeviceChanged([ComAliasName("MMDevAPI.Interop.EDataFlow")] [In] EDataFlow flow, [ComAliasName("MMDevAPI.Interop.ERole")] [In] ERole role, [MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrDefaultDeviceId);
[MethodImpl(MethodImplOptions.InternalCall)]
void OnPropertyValueChanged([MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrDeviceId, [In] PropertyKey key);
}
[Guid("886D8EEB-8CF2-4446-8D02-CDBA1DBDCF99"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[ComImport]
public interface IPropertyStore
{
[MethodImpl(MethodImplOptions.InternalCall)]
void GetCount(out uint cProps);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetAt([In] uint iProp, out PropertyKey pkey);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetValue([In] ref PropertyKey key, out PROPVARIANT pv);
[MethodImpl(MethodImplOptions.InternalCall)]
void SetValue([In] ref PropertyKey key, [In] ref PROPVARIANT propvar);
[MethodImpl(MethodImplOptions.InternalCall)]
void Commit();
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
public struct PropertyKey
{
public static PropertyKey PKEY_Device_DeviceDesc = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 2 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_HardwareIds = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 3 }; // DEVPROP_TYPE_STRING_LIST
public static PropertyKey PKEY_Device_Service = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 6 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_Class = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 9 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_Driver = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 11 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_ConfigFlags = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 12 }; // DEVPROP_TYPE_UINT32
public static PropertyKey PKEY_Device_Manufacturer = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 13 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_FriendlyName = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 14 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_LocationInfo = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 15 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_Capabilities = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 17 }; // DEVPROP_TYPE_UNINT32
public static PropertyKey PKEY_Device_BusNumber = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 23 }; // DEVPROP_TYPE_UINT32
public static PropertyKey PKEY_Device_EnumeratorName = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 24 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_DevType = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 27 }; // DEVPROP_TYPE_UINT32
public static PropertyKey PKEY_Device_Characteristics = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 29 }; // DEVPROP_TYPE_UINT32
public static PropertyKey PKEY_Device_ManufacturerAttributes = new PropertyKey { fmtid = new Guid(unchecked((int)0x80d81ea6), unchecked((short)0x7473), 0x4b0c, 0x82, 0x16, 0xef, 0xc1, 0x1a, 0x2c, 0x4c, 0x8b), pid = 4 }; // DEVPROP_TYPE_UINT32
public static PropertyKey PKEY_DeviceClass_IconPath = new PropertyKey { fmtid = new Guid(unchecked((int)0x259abffc), 0x50a7, 0x47ce, 0xaf, 0x8, 0x68, 0xc9, 0xa7, 0xd7, 0x33, 0x66), pid = 12 }; // DEVPROP_TYPE_STRING_LIST
public static PropertyKey PKEY_DeviceClass_ClassCoInstallers = new PropertyKey { fmtid = new Guid(unchecked((int)0x713d1703), 0xa2e2, 0x49f5, 0x92, 0x14, 0x56, 0x47, 0x2e, 0xf3, 0xda, 0x5c), pid = 2 }; // DEVPROP_TYPE_STRING_LIST
public static PropertyKey PKEY_DeviceInterface_FriendlyName = new PropertyKey { fmtid = new Guid(unchecked((int)0x026e516e), 0xb814, 0x414b, 0x83, 0xcd, 0x85, 0x6d, 0x6f, 0xef, 0x48, 0x22), pid = 2 }; // DEVPROP_TYPE_STRING
public Guid fmtid;
public uint pid;
public static IEnumerable<PropertyKey> GetPropertyKeys()
{
var keyFields = typeof(PropertyKey).GetFields(BindingFlags.Public | BindingFlags.Static);
return keyFields.Where(fieldInfo => fieldInfo.FieldType == typeof(PropertyKey))
.Select(fieldInfo => (PropertyKey)fieldInfo.GetValue(null));
}
public static string GetKeyName(PropertyKey propertyKey)
{
var keyFields = typeof(PropertyKey).GetFields(BindingFlags.Public | BindingFlags.Static);
return keyFields.Select(fieldInfo => new { fieldInfo, value = (PropertyKey)fieldInfo.GetValue(null) })
.Where(@t => propertyKey.pid == @t.value.pid && propertyKey.fmtid == @t.value.fmtid)
.Select(@t => @t.fieldInfo.Name).FirstOrDefault();
}
}
[StructLayout(LayoutKind.Sequential, Pack = 8)]
public struct PROPVARIANT
{
public ushort variantType;
public byte wReserved1;
public byte wReserved2;
public uint wReserved3;
public PROPVARIANTVALUE value;
public object Value
{
get
{
switch ((VarEnum)variantType)
{
case VarEnum.VT_EMPTY:
return null;
case VarEnum.VT_NULL:
return null;
case VarEnum.VT_VARIANT:
break;
case VarEnum.VT_DECIMAL:
return value.cyVal;
case VarEnum.VT_VOID:
break;
case VarEnum.VT_HRESULT:
break;
case VarEnum.VT_PTR:
break;
case VarEnum.VT_SAFEARRAY:
break;
case VarEnum.VT_CARRAY:
break;
case VarEnum.VT_USERDEFINED:
break;
case VarEnum.VT_RECORD:
break;
case VarEnum.VT_STREAM:
break;
case VarEnum.VT_STORAGE:
break;
case VarEnum.VT_STREAMED_OBJECT:
break;
case VarEnum.VT_STORED_OBJECT:
break;
case VarEnum.VT_BLOB_OBJECT:
break;
case VarEnum.VT_CF:
break;
case VarEnum.VT_CLSID:
return Marshal.PtrToStructure(value.pVal, typeof(Guid));
case VarEnum.VT_VECTOR:
break;
case VarEnum.VT_ARRAY:
break;
case VarEnum.VT_BYREF:
break;
case VarEnum.VT_I1:
return value.cVal;
case VarEnum.VT_UI1:
return value.bVal;
case VarEnum.VT_I2:
return value.iVal;
case VarEnum.VT_UI2:
return value.uiVal;
case VarEnum.VT_I4:
case VarEnum.VT_INT:
return value.intVal;
case VarEnum.VT_UI4:
case VarEnum.VT_UINT:
return value.uintVal;
case VarEnum.VT_I8:
return value.hVal;
case VarEnum.VT_UI8:
return value.uhVal;
case VarEnum.VT_R4:
return value.fltVal;
case VarEnum.VT_R8:
return value.dblVal;
case VarEnum.VT_BOOL:
return value.boolVal;
case VarEnum.VT_ERROR:
return value.scode;
case VarEnum.VT_CY:
return value.cyVal;
case VarEnum.VT_DATE:
return value.date;
case VarEnum.VT_FILETIME:
return DateTime.FromFileTime(value.hVal);
case VarEnum.VT_BSTR:
return Marshal.PtrToStringBSTR(value.pVal);
case VarEnum.VT_BLOB:
var blob = value.blob;
var blobData = new byte[blob.cbSize];
Marshal.Copy(blob.pBlobData, blobData, 0, (int)blob.cbSize);
return blobData;
case VarEnum.VT_LPSTR:
return Marshal.PtrToStringAnsi(value.pVal);
case VarEnum.VT_LPWSTR:
return Marshal.PtrToStringUni(value.pVal);
case VarEnum.VT_UNKNOWN:
return Marshal.GetObjectForIUnknown(value.pVal);
case VarEnum.VT_DISPATCH:
return value.pVal;
//default:
// throw new NotSupportedException("The type of this variable is not support ('" + variantType + "')");
}
return string.Format("unsupported {0}", ((VarEnum)variantType));
//throw new NotSupportedException("The type of this variable is not support ('" + variantType.ToString() + "')");
}
}
}
[ComConversionLoss]
[StructLayout(LayoutKind.Explicit, Pack = 8, Size = 8)]
public struct PROPVARIANTVALUE
{
[FieldOffset(0)]
public sbyte cVal;
[FieldOffset(0)]
public byte bVal;
[FieldOffset(0)]
public short iVal;
[FieldOffset(0)]
public ushort uiVal;
[FieldOffset(0)]
public int intVal;
[FieldOffset(0)]
public uint uintVal;
[FieldOffset(0)]
public long hVal;
[FieldOffset(0)]
public ulong uhVal;
[FieldOffset(0)]
public float fltVal;
[FieldOffset(0)]
public double dblVal;
[FieldOffset(0)]
public short boolVal;
[FieldOffset(0)]
[MarshalAs(UnmanagedType.Error)]
public int scode;
[FieldOffset(0)]
[MarshalAs(UnmanagedType.Currency)]
public decimal cyVal;
[FieldOffset(0)]
public DateTime date;
[FieldOffset(0)]
public tagFILETIME filetime;
[FieldOffset(0)]
public tagARRAY array;
[FieldOffset(0)]
public tagBLOB blob;
[ComConversionLoss]
[FieldOffset(0)]
public IntPtr pVal;
}
[ComConversionLoss]
[StructLayout(LayoutKind.Sequential, Pack = 4)]
public struct tagARRAY
{
public uint cElems;
[ComConversionLoss]
public IntPtr pElems;
}
[ComConversionLoss]
[StructLayout(LayoutKind.Sequential, Pack = 4)]
public struct tagBLOB
{
public uint cbSize;
[ComConversionLoss]
public IntPtr pBlobData;
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
public struct tagFILETIME
{
public uint dwLowDateTime;
public uint dwHighDateTime;
}
[StructLayout(LayoutKind.Sequential, Pack = 8)]
public struct tagLARGEINTEGER
{
public long QuadPart;
}
[StructLayout(LayoutKind.Sequential, Pack = 8)]
public struct tagULARGEINTEGER
{
public ulong QuadPart;
}
}
没有示例如何通过 C# 检测耳机是否插入。
我想应该是一些事件...
使用 WMI 有意义吗？
ManagementObjectSearcher searcher = new ManagementObjectSearcher("root\cimv2",
"SELECT * FROM Win32_SoundDevice");
foreach (ManagementObject queryObj in searcher.Get())
{
Console.WriteLine("-----------------------------------");
Console.WriteLine("Win32_SoundDevice instance");
Console.WriteLine("-----------------------------------");
Console.WriteLine("StatusInfo: {0}", queryObj["StatusInfo"]);
}
有人愿意提供吗？
谢谢！
可以使用 IMMDeviceEnumerator::RegisterEndpointNotificationCallback 方法检测此类更改。
如果您想在 C# 中处理此问题，您将需要一个已由 Akos Mattiassich 实现的托管包装器。你可以在这里找到一个完整的例子：Managed Wrapper around MMAudioDeviceApi
他说：
The program can play test sound on selected devices and it updates the list automatically on changes eg. through the control panel or in case of plugging new device physically.
我不建议您自己使用 COM+ API。
Install-Package NAudio
您应该能够枚举具有 plugged/unplugged 状态的音频设备，如下所示：
var enumerator = new NAudio.CoreAudioApi.MMDeviceEnumerator();
// Allows you to enumerate rendering devices in certain states
var endpoints = enumerator.EnumerateAudioEndPoints(
DataFlow.Render,
DeviceState.Unplugged | DeviceState.Active);
foreach (var endpoint in endpoints)
{
Console.WriteLine("{0} - {1}", endpoint.DeviceFriendlyName, endpoint.State);
}
// Aswell as hook to the actual event
enumerator.RegisterEndpointNotificationCallback(new NotificationClient());
其中NotificationClient实现如下：
class NotificationClient : NAudio.CoreAudioApi.Interfaces.IMMNotificationClient
{
void IMMNotificationClient.OnDeviceStateChanged(string deviceId, DeviceState newState)
{
Console.WriteLine("OnDeviceStateChanged\n Device Id -->{0} : Device State {1}", deviceId, newState);
}
void IMMNotificationClient.OnDeviceAdded(string pwstrDeviceId) { }
void IMMNotificationClient.OnDeviceRemoved(string deviceId) { }
void IMMNotificationClient.OnDefaultDeviceChanged(DataFlow flow, Role role, string defaultDeviceId) { }
void IMMNotificationClient.OnPropertyValueChanged(string pwstrDeviceId, PropertyKey key) { }
}
应该产生类似的结果：
我认为它在上面的屏幕截图中检测到两次 plugging/unplugging 的原因是因为在 Macbook 上他们使用一个插孔用于麦克风和耳机。
下面是一个（最小的）Windows 表单应用程序示例，它基于 IMMNotificationClient interface，不需要任何第三方库。
只要多媒体设备 plugged/unplugged，您就会收到通知。然后您可以查看设备属性并采取适当的措施。您还可以枚举现有设备并检查耳机是否已插入（请参阅 IsConnected 属性）。
创建 COM 互操作
请注意，示例代码包含相关 COM 对象的定义。在生产中，我可能会为底层 mmdevapi.dll 创建一个 COM 互操作程序集。您可以首先从头文件创建类型库（Windows 需要安装 SDK）：
midl /out c:\tmp /header "C:\Program Files (x86)\Windows Kits.1\Include\um\mmdeviceapi.h" "C:\Program Files (x86)\Windows Kits.1\Include\um\mmdeviceapi.idl"
然后您需要使用 tlbimp.exe:
tlbimp /out:MMDevAPI.Interop.dll mmdeviceapi.tlb
MultiMediaNotificationListener 示例
using System;
using System.Runtime.InteropServices;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Windows.Forms;
namespace MultiMediaNotificationListenerSample
{
class MainWindow : Form
{
[STAThread]
private static void Main(string[] args)
{
using (var notificationClient = new MultiMediaNotificationListener())
{
Trace.WriteLine(string.Format("Headphone is {0}connected", notificationClient.IsConnected ? "": "not "));
Application.Run(new MainWindow());
}
}
}
class MultiMediaNotificationListener : IMMNotificationClient, IDisposable
{
private readonly IMMDeviceEnumerator _deviceEnumerator;
public MultiMediaNotificationListener()
{
if (Environment.OSVersion.Version.Major < 6)
{
throw new NotSupportedException("This functionality is only supported on Windows Vista or newer.");
}
_deviceEnumerator = (IMMDeviceEnumerator)new MMDeviceEnumerator();
_deviceEnumerator.RegisterEndpointNotificationCallback(this);
}
~MultiMediaNotificationListener()
{
Dispose(false);
}
public bool IsConnected
{
get
{
IMMDeviceCollection deviceCollection;
_deviceEnumerator.EnumAudioEndpoints(EDataFlow.eRender, (uint)DeviceState.DEVICE_STATE_ACTIVE, out deviceCollection);
uint deviceCount = 0;
deviceCollection.GetCount(out deviceCount);
for (uint i = 0; i < deviceCount; i++)
{
IMMDevice device;
deviceCollection.Item(i, out device);
IPropertyStore propertyStore;
device.OpenPropertyStore((uint)STGM.STGM_READ, out propertyStore);
PROPVARIANT property;
propertyStore.GetValue(ref PropertyKey.PKEY_Device_DeviceDesc, out property);
var value = (string)property.Value;
Marshal.ReleaseComObject(propertyStore);
Marshal.ReleaseComObject(device);
if (value == "Headphones")
{
return true;
}
}
Marshal.ReleaseComObject(deviceCollection);
return false;
}
}
public void OnDefaultDeviceChanged(EDataFlow dataFlow, ERole deviceRole, string pwstrDefaultDeviceId)
{
}
public void OnDeviceStateChanged(string pwstrDeviceId, uint dwNewState)
{
IMMDevice device;
_deviceEnumerator.GetDevice(pwstrDeviceId, out device);
IPropertyStore propertyStore;
device.OpenPropertyStore((uint)STGM.STGM_READ, out propertyStore);
Trace.WriteLine(string.Format("OnDeviceStateChanged:\n Device Id {0}\tDevice State {1}", pwstrDeviceId, (DeviceState)dwNewState));
var properties = PropertyKey.GetPropertyKeys()
.Select(
propertyKey =>
{
PROPVARIANT property;
propertyStore.GetValue(ref propertyKey, out property);
return new { Key = PropertyKey.GetKeyName(propertyKey), Value = property.Value };
})
.Where(@t => @t.Value != null);
foreach (var property in properties)
{
Trace.WriteLine(string.Format(" {0}\t{1}", property.Key, property.Value));
}
Marshal.ReleaseComObject(propertyStore);
Marshal.ReleaseComObject(device);
}
public void OnDeviceAdded(string deviceId)
{
}
public void OnDeviceRemoved(string deviceId)
{
}
public void OnPropertyValueChanged(string pwstrDeviceId, PropertyKey key)
{
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
private void Dispose(bool disposing)
{
_deviceEnumerator.UnregisterEndpointNotificationCallback(this);
Marshal.ReleaseComObject(_deviceEnumerator);
}
}
public enum STGM : uint
{
STGM_READ = 0x0,
STGM_WRITE = 0x1,
STGM_READWRITE = 0x2
}
public enum DeviceState
{
DEVICE_STATE_ACTIVE = 0x00000001,
DEVICE_STATE_DISABLED = 0x00000002,
DEVICE_STATE_NOTPRESENT = 0x00000004,
DEVICE_STATE_UNPLUGGED = 0x00000008,
DEVICE_STATEMASK_ALL = 0x0000000f
}
[ComImport]
[Guid("BCDE0395-E52F-467C-8E3D-C4579291692E")]
internal class MMDeviceEnumerator
{
}
public enum EDataFlow
{
eRender,
eCapture,
eAll,
EDataFlow_enum_count
}
public enum ERole
{
eConsole,
eMultimedia,
eCommunications,
ERole_enum_count
}
[Guid("0BD7A1BE-7A1A-44DB-8397-CC5392387B5E"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), TypeLibType(TypeLibTypeFlags.FNonExtensible)]
[ComImport]
public interface IMMDeviceCollection
{
[MethodImpl(MethodImplOptions.InternalCall)]
void GetCount(out uint pcDevices);
[MethodImpl(MethodImplOptions.InternalCall)]
void Item([In] uint nDevice, [MarshalAs(UnmanagedType.Interface)] out IMMDevice ppDevice);
}
[Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), TypeLibType(TypeLibTypeFlags.FNonExtensible)]
[ComImport]
public interface IMMDeviceEnumerator
{
[MethodImpl(MethodImplOptions.InternalCall)]
void EnumAudioEndpoints([ComAliasName("MMDevAPI.Interop.EDataFlow")] [In] EDataFlow dataFlow, [In] uint dwStateMask, [MarshalAs(UnmanagedType.Interface)] out IMMDeviceCollection ppDevices);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetDefaultAudioEndpoint([ComAliasName("MMDevAPI.Interop.EDataFlow")] [In] EDataFlow dataFlow, [ComAliasName("MMDevAPI.Interop.ERole")] [In] ERole role, [MarshalAs(UnmanagedType.Interface)] out IMMDevice ppEndpoint);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetDevice([MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrId, [MarshalAs(UnmanagedType.Interface)] out IMMDevice ppDevice);
[MethodImpl(MethodImplOptions.InternalCall)]
void RegisterEndpointNotificationCallback([MarshalAs(UnmanagedType.Interface)] [In] IMMNotificationClient pClient);
[MethodImpl(MethodImplOptions.InternalCall)]
void UnregisterEndpointNotificationCallback([MarshalAs(UnmanagedType.Interface)] [In] IMMNotificationClient pClient);
}
[Guid("D666063F-1587-4E43-81F1-B948E807363F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), TypeLibType(TypeLibTypeFlags.FNonExtensible)]
[ComImport]
public interface IMMDevice
{
[MethodImpl(MethodImplOptions.InternalCall)]
void Activate([In] ref Guid iid, [In] uint dwClsCtx, [In] IntPtr pActivationParams, [MarshalAs(UnmanagedType.IUnknown)] out object ppInterface);
[MethodImpl(MethodImplOptions.InternalCall)]
void OpenPropertyStore([In] uint stgmAccess, [MarshalAs(UnmanagedType.Interface)] out IPropertyStore ppProperties);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetId([MarshalAs(UnmanagedType.LPWStr)] out string ppstrId);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetState(out uint pdwState);
}
[Guid("7991EEC9-7E89-4D85-8390-6C703CEC60C0"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), TypeLibType(TypeLibTypeFlags.FNonExtensible)]
[ComImport]
public interface IMMNotificationClient
{
[MethodImpl(MethodImplOptions.InternalCall)]
void OnDeviceStateChanged([MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrDeviceId, [In] uint dwNewState);
[MethodImpl(MethodImplOptions.InternalCall)]
void OnDeviceAdded([MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrDeviceId);
[MethodImpl(MethodImplOptions.InternalCall)]
void OnDeviceRemoved([MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrDeviceId);
[MethodImpl(MethodImplOptions.InternalCall)]
void OnDefaultDeviceChanged([ComAliasName("MMDevAPI.Interop.EDataFlow")] [In] EDataFlow flow, [ComAliasName("MMDevAPI.Interop.ERole")] [In] ERole role, [MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrDefaultDeviceId);
[MethodImpl(MethodImplOptions.InternalCall)]
void OnPropertyValueChanged([MarshalAs(UnmanagedType.LPWStr)] [In] string pwstrDeviceId, [In] PropertyKey key);
}
[Guid("886D8EEB-8CF2-4446-8D02-CDBA1DBDCF99"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[ComImport]
public interface IPropertyStore
{
[MethodImpl(MethodImplOptions.InternalCall)]
void GetCount(out uint cProps);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetAt([In] uint iProp, out PropertyKey pkey);
[MethodImpl(MethodImplOptions.InternalCall)]
void GetValue([In] ref PropertyKey key, out PROPVARIANT pv);
[MethodImpl(MethodImplOptions.InternalCall)]
void SetValue([In] ref PropertyKey key, [In] ref PROPVARIANT propvar);
[MethodImpl(MethodImplOptions.InternalCall)]
void Commit();
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
public struct PropertyKey
{
public static PropertyKey PKEY_Device_DeviceDesc = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 2 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_HardwareIds = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 3 }; // DEVPROP_TYPE_STRING_LIST
public static PropertyKey PKEY_Device_Service = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 6 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_Class = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 9 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_Driver = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 11 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_ConfigFlags = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 12 }; // DEVPROP_TYPE_UINT32
public static PropertyKey PKEY_Device_Manufacturer = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 13 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_FriendlyName = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 14 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_LocationInfo = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 15 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_Capabilities = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 17 }; // DEVPROP_TYPE_UNINT32
public static PropertyKey PKEY_Device_BusNumber = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 23 }; // DEVPROP_TYPE_UINT32
public static PropertyKey PKEY_Device_EnumeratorName = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 24 }; // DEVPROP_TYPE_STRING
public static PropertyKey PKEY_Device_DevType = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 27 }; // DEVPROP_TYPE_UINT32
public static PropertyKey PKEY_Device_Characteristics = new PropertyKey { fmtid = new Guid(unchecked((int)0xa45c254e), unchecked((short)0xdf1c), 0x4efd, 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0), pid = 29 }; // DEVPROP_TYPE_UINT32
public static PropertyKey PKEY_Device_ManufacturerAttributes = new PropertyKey { fmtid = new Guid(unchecked((int)0x80d81ea6), unchecked((short)0x7473), 0x4b0c, 0x82, 0x16, 0xef, 0xc1, 0x1a, 0x2c, 0x4c, 0x8b), pid = 4 }; // DEVPROP_TYPE_UINT32
public static PropertyKey PKEY_DeviceClass_IconPath = new PropertyKey { fmtid = new Guid(unchecked((int)0x259abffc), 0x50a7, 0x47ce, 0xaf, 0x8, 0x68, 0xc9, 0xa7, 0xd7, 0x33, 0x66), pid = 12 }; // DEVPROP_TYPE_STRING_LIST
public static PropertyKey PKEY_DeviceClass_ClassCoInstallers = new PropertyKey { fmtid = new Guid(unchecked((int)0x713d1703), 0xa2e2, 0x49f5, 0x92, 0x14, 0x56, 0x47, 0x2e, 0xf3, 0xda, 0x5c), pid = 2 }; // DEVPROP_TYPE_STRING_LIST
public static PropertyKey PKEY_DeviceInterface_FriendlyName = new PropertyKey { fmtid = new Guid(unchecked((int)0x026e516e), 0xb814, 0x414b, 0x83, 0xcd, 0x85, 0x6d, 0x6f, 0xef, 0x48, 0x22), pid = 2 }; // DEVPROP_TYPE_STRING
public Guid fmtid;
public uint pid;
public static IEnumerable<PropertyKey> GetPropertyKeys()
{
var keyFields = typeof(PropertyKey).GetFields(BindingFlags.Public | BindingFlags.Static);
return keyFields.Where(fieldInfo => fieldInfo.FieldType == typeof(PropertyKey))
.Select(fieldInfo => (PropertyKey)fieldInfo.GetValue(null));
}
public static string GetKeyName(PropertyKey propertyKey)
{
var keyFields = typeof(PropertyKey).GetFields(BindingFlags.Public | BindingFlags.Static);
return keyFields.Select(fieldInfo => new { fieldInfo, value = (PropertyKey)fieldInfo.GetValue(null) })
.Where(@t => propertyKey.pid == @t.value.pid && propertyKey.fmtid == @t.value.fmtid)
.Select(@t => @t.fieldInfo.Name).FirstOrDefault();
}
}
[StructLayout(LayoutKind.Sequential, Pack = 8)]
public struct PROPVARIANT
{
public ushort variantType;
public byte wReserved1;
public byte wReserved2;
public uint wReserved3;
public PROPVARIANTVALUE value;
public object Value
{
get
{
switch ((VarEnum)variantType)
{
case VarEnum.VT_EMPTY:
return null;
case VarEnum.VT_NULL:
return null;
case VarEnum.VT_VARIANT:
break;
case VarEnum.VT_DECIMAL:
return value.cyVal;
case VarEnum.VT_VOID:
break;
case VarEnum.VT_HRESULT:
break;
case VarEnum.VT_PTR:
break;
case VarEnum.VT_SAFEARRAY:
break;
case VarEnum.VT_CARRAY:
break;
case VarEnum.VT_USERDEFINED:
break;
case VarEnum.VT_RECORD:
break;
case VarEnum.VT_STREAM:
break;
case VarEnum.VT_STORAGE:
break;
case VarEnum.VT_STREAMED_OBJECT:
break;
case VarEnum.VT_STORED_OBJECT:
break;
case VarEnum.VT_BLOB_OBJECT:
break;
case VarEnum.VT_CF:
break;
case VarEnum.VT_CLSID:
return Marshal.PtrToStructure(value.pVal, typeof(Guid));
case VarEnum.VT_VECTOR:
break;
case VarEnum.VT_ARRAY:
break;
case VarEnum.VT_BYREF:
break;
case VarEnum.VT_I1:
return value.cVal;
case VarEnum.VT_UI1:
return value.bVal;
case VarEnum.VT_I2:
return value.iVal;
case VarEnum.VT_UI2:
return value.uiVal;
case VarEnum.VT_I4:
case VarEnum.VT_INT:
return value.intVal;
case VarEnum.VT_UI4:
case VarEnum.VT_UINT:
return value.uintVal;
case VarEnum.VT_I8:
return value.hVal;
case VarEnum.VT_UI8:
return value.uhVal;
case VarEnum.VT_R4:
return value.fltVal;
case VarEnum.VT_R8:
return value.dblVal;
case VarEnum.VT_BOOL:
return value.boolVal;
case VarEnum.VT_ERROR:
return value.scode;
case VarEnum.VT_CY:
return value.cyVal;
case VarEnum.VT_DATE:
return value.date;
case VarEnum.VT_FILETIME:
return DateTime.FromFileTime(value.hVal);
case VarEnum.VT_BSTR:
return Marshal.PtrToStringBSTR(value.pVal);
case VarEnum.VT_BLOB:
var blob = value.blob;
var blobData = new byte[blob.cbSize];
Marshal.Copy(blob.pBlobData, blobData, 0, (int)blob.cbSize);
return blobData;
case VarEnum.VT_LPSTR:
return Marshal.PtrToStringAnsi(value.pVal);
case VarEnum.VT_LPWSTR:
return Marshal.PtrToStringUni(value.pVal);
case VarEnum.VT_UNKNOWN:
return Marshal.GetObjectForIUnknown(value.pVal);
case VarEnum.VT_DISPATCH:
return value.pVal;
//default:
// throw new NotSupportedException("The type of this variable is not support ('" + variantType + "')");
}
return string.Format("unsupported {0}", ((VarEnum)variantType));
//throw new NotSupportedException("The type of this variable is not support ('" + variantType.ToString() + "')");
}
}
}
[ComConversionLoss]
[StructLayout(LayoutKind.Explicit, Pack = 8, Size = 8)]
public struct PROPVARIANTVALUE
{
[FieldOffset(0)]
public sbyte cVal;
[FieldOffset(0)]
public byte bVal;
[FieldOffset(0)]
public short iVal;
[FieldOffset(0)]
public ushort uiVal;
[FieldOffset(0)]
public int intVal;
[FieldOffset(0)]
public uint uintVal;
[FieldOffset(0)]
public long hVal;
[FieldOffset(0)]
public ulong uhVal;
[FieldOffset(0)]
public float fltVal;
[FieldOffset(0)]
public double dblVal;
[FieldOffset(0)]
public short boolVal;
[FieldOffset(0)]
[MarshalAs(UnmanagedType.Error)]
public int scode;
[FieldOffset(0)]
[MarshalAs(UnmanagedType.Currency)]
public decimal cyVal;
[FieldOffset(0)]
public DateTime date;
[FieldOffset(0)]
public tagFILETIME filetime;
[FieldOffset(0)]
public tagARRAY array;
[FieldOffset(0)]
public tagBLOB blob;
[ComConversionLoss]
[FieldOffset(0)]
public IntPtr pVal;
}
[ComConversionLoss]
[StructLayout(LayoutKind.Sequential, Pack = 4)]
public struct tagARRAY
{
public uint cElems;
[ComConversionLoss]
public IntPtr pElems;
}
[ComConversionLoss]
[StructLayout(LayoutKind.Sequential, Pack = 4)]
public struct tagBLOB
{
public uint cbSize;
[ComConversionLoss]
public IntPtr pBlobData;
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
public struct tagFILETIME
{
public uint dwLowDateTime;
public uint dwHighDateTime;
}
[StructLayout(LayoutKind.Sequential, Pack = 8)]
public struct tagLARGEINTEGER
{
public long QuadPart;
}
[StructLayout(LayoutKind.Sequential, Pack = 8)]
public struct tagULARGEINTEGER
{
public ulong QuadPart;
}
}