notify/Notify/Interop/Sound.cs

using System;
using System.IO;
using System.Runtime.InteropServices;
using Avalonia.Platform;

namespace Notify.Interop;

/// <summary>
/// 播放打包的提示音 wav
///
/// 用 winmm 的 PlaySound 从内存异步播放；为配合 SND_ASYNC，wav 拷到不会被 GC
/// 移动的非托管内存里常驻
/// </summary>
internal static partial class Sound
{
    private const uint SND_ASYNC = 0x0001;
    private const uint SND_NODEFAULT = 0x0002;
    private const uint SND_MEMORY = 0x0004;

    private static IntPtr _wavPtr;
    private static DateTime _lastPlay = DateTime.MinValue;

    [LibraryImport("winmm.dll", EntryPoint = "PlaySoundW")]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static partial bool PlaySound(IntPtr pszSound, IntPtr hmod, uint fdwSound);

    public static void Play()
    {
        // 防连环音：300ms 内只响一次
        var now = DateTime.UtcNow;
        if ((now - _lastPlay).TotalMilliseconds < 300)
        {
            return;
        }

        _lastPlay = now;

        try
        {
            EnsureLoaded();
            if (_wavPtr != IntPtr.Zero)
            {
                PlaySound(_wavPtr, IntPtr.Zero, SND_MEMORY | SND_ASYNC | SND_NODEFAULT);
            }
        }
        catch
        {
            // 播放失败无所谓
        }
    }

    private static void EnsureLoaded()
    {
        if (_wavPtr != IntPtr.Zero)
        {
            return;
        }

        using var s = AssetLoader.Open(new Uri("avares://notify/Assets/notification.wav"));
        using var ms = new MemoryStream();
        s.CopyTo(ms);
        var bytes = ms.ToArray();

        _wavPtr = Marshal.AllocHGlobal(bytes.Length);
        Marshal.Copy(bytes, 0, _wavPtr, bytes.Length);
    }
}