由于Json.NET当前没有将集合序列化为NDJSON的内置方法，因此最简单的答案是

TextWriter

使用单独

JsonTextWriter

的一行写一行，并为每行设置[`CloseOutput

false`](http://www.newtonsoft.com/json/help/html/P_Newtonsoft_Json_JsonWriter_CloseOutput.htm)：

public static partial class JsonExtensions{    public static void TonewlineDelimitedJson<T>(Stream stream, IEnumerable<T> items)    {        // Let caller dispose the underlying stream         using (var textWriter = new StreamWriter(stream, new UTF8Encoding(false, true), 1024, true))        { TonewlineDelimitedJson(textWriter, items);        }    }    public static void TonewlineDelimitedJson<T>(TextWriter textWriter, IEnumerable<T> items)    {        var serializer = JsonSerializer.CreateDefault();        foreach (var item in items)        { // Formatting.None is the default; I set it here for clarity. using (var writer = new JsonTextWriter(textWriter) { Formatting = Formatting.None, CloseOutput = false }) {     serializer.Serialize(writer, item); } // https://web.archive.org/web/20180513150745/http://specs.okfnlabs.org/ndjson/ // Each JSON text MUST conform to the [RFC7159] standard and MUST be written to the stream followed by the newline character n (0x0A).  // The newline charater MAY be preceeded by a carriage return r (0x0D). The JSON texts MUST NOT contain newlines or carriage returns. textWriter.Write("n");        }    }}

样品提琴。

由于单个NDJSON行可能很短，但行数可能很大，因此此答案提出了一种流传输解决方案，以避免分配大于85kb的单个字符串的必要性。如 Newtonsoft
Json.NET Performance
Tips中所述

，此类大字符串最终会出现在大对象堆上，并可能随后降低应用程序性能。