如何在ASP.NET Core中正确流式传输响应?有一个像这样的控制器(UPDATED CODE):
[HttpGet("test")]
public async Task GetTest()
{
HttpContext.Response.ContentType = "text/plain";
using (var writer = new StreamWriter(HttpContext.Response.Body))
await writer.WriteLineAsync("Hello World");
}
Firefox / Edge浏览器显示
Hello World
,而Chrome /邮递员报告错误:
本地主机页面不起作用
localhost意外关闭了连接。
ERR_INCOMPLETE_CHUNKED_ENCODING
P.S。我将要流式传输许多内容,因此无法提前指定Content-Length标头。
[流式传输应像下载文件一样显示在浏览器中的响应,您应使用FileStreamResult
:
[HttpGet]
public FileStreamResult GetTest()
{
var stream = new MemoryStream(Encoding.ASCII.GetBytes("Hello World"));
return new FileStreamResult(stream, new MediaTypeHeaderValue("text/plain"))
{
FileDownloadName = "test.txt"
};
}
即使先前写入null
时,也可能返回EmptyResult()
或Response.Body
(等效)。如果该方法返回ActionResult
以便能够轻松使用所有其他结果(例如BadQuery()
),则可能会很有用。
[HttpGet("test")]
public ActionResult Test()
{
Response.StatusCode = 200;
Response.ContentType = "text/plain";
using (var sw = new StreamWriter(Response.Body))
{
sw.Write("something");
}
return null;
}
我也想知道如何做到这一点,并且发现原始问题的代码实际上可以在ASP.NET Core 2.1.0-rc1-final
上正常运行,Chrome(和其他一些浏览器)和JavaScript应用程序都不会因此类端点而失败。
我想添加的次要功能只是设置StatusCode并关闭响应流以使响应得到满足:
[HttpGet("test")]
public void Test()
{
Response.StatusCode = 200;
Response.ContentType = "text/plain";
using (Response.Body)
{
using (var sw = new StreamWriter(Response.Body))
{
sw.Write("Hi there!");
}
}
}
这个问题有点老了,但是我找不到我想做的更好的答案。我发现诀窍是为您要编写的每个内容块打开一个新的StreamWriter。只需执行以下操作:
[HttpDelete]
public void Content()
{
Response.StatusCode = 200;
Response.ContentType = "text/html";
// the easiest way to implement a streaming response, is to simply flush the stream after every write.
// If you are writing to the stream asynchronously, you will want to use a Synchronized StreamWriter.
using (var sw = StreamWriter.Synchronized(new StreamWriter(Response.Body)))
{
foreach (var item in new int[] { 1, 2, 3, 4, })
{
Thread.Sleep(1000);
sw.Write($"<p>Hi there {item}!</p>");
sw.Flush();
}
};
}
您可以使用以下命令进行卷曲测试:curl -NX DELETE <CONTROLLER_ROUTE>/content
类似的事情可能起作用:
[HttpGet]
public async Task<IActionResult> GetTest()
{
var contentType = "text/plain";
using (var stream = new MemoryStream(Encoding.ASCII.GetBytes("Hello World")))
return new FileStreamResult(stream, contentType);
}