从Console.ReadList/Read 的源码中，可学习到.NET CORE 是怎么样来读取输入流。

也可以学习到是如何使用P/Invoke来调用系统API

Console.ReadList 的源码为

        [MethodImplAttribute(MethodImplOptions.NoInlining)]public static string ReadLine(){return In.ReadLine();}

其中In为。

internal static T EnsureInitialized<T>(ref T field, Func<T> initializer) where T : class =>LazyInitializer.EnsureInitialized(ref field, ref InternalSyncObject, initializer);public static TextReader In => EnsureInitialized(ref s_in, () => ConsolePal.GetOrCreateReader());

可以看到他是个TextRead

internal static TextReader GetOrCreateReader(){Stream inputStream = OpenStandardInput();return SyncTextReader.GetSynchronizedTextReader(inputStream == Stream.Null ?StreamReader.Null :new StreamReader(stream: inputStream,encoding: new ConsoleEncoding(Console.InputEncoding),detectEncodingFromByteOrderMarks: false,bufferSize: Console.ReadBufferSize,leaveOpen: true));}

继续跳转，查看方法OpenStandardInput

public static Stream OpenStandardInput(){return GetStandardFile(Interop.Kernel32.HandleTypes.STD_INPUT_HANDLE, FileAccess.Read);}

继续看方法

private static Stream GetStandardFile(int handleType, FileAccess access){IntPtr handle = Interop.Kernel32.GetStdHandle(handleType);// 此处源码一坨注释被我删掉了。^_^if (handle == IntPtr.Zero || handle == InvalidHandleValue ||(access != FileAccess.Read && !ConsoleHandleIsWritable(handle))){return Stream.Null;}return new WindowsConsoleStream(handle, access, GetUseFileAPIs(handleType));}

哈哈，终于要看到了Interop.Kernel32.GetStdHandle 这个方法就是调用系统API接口函数的方法。

<!-- Windows --><ItemGroup Condition="'$(TargetsWindows)' == 'true'"><Compile Include="$(CommonPath)\CoreLib\Interop\Windows\Kernel32\Interop.GetStdHandle.cs"><Link>Common\CoreLib\Interop\Windows\Interop.GetStdHandle.cs</Link></Compile>
</ItemGroup>
<!-- Unix -->
<ItemGroup Condition=" '$(TargetsUnix)' == 'true'">
</ItemGroup>

回到GetStandardFile 中看到返回一个WindowsConsoleStream

useFileAPIs 参数，决定是使用操作系统 ReadFile还是 ReadConsole API。

对于.NET CORE 源码中有很多 XXXX.Unix.cs,XXXX.Windows.cs