我也遇到过同样的问题，在我们的代码深处，我们有这样的伪代码:

创建iframe 加载iframe提交一个表单 2秒后，移除iframe

thus, when the server takes more than 2 seconds to respond the iframe to which the server was writing the response to, was removed, but the response was still to be written , but there was no iframe to write , thus chrome cancelled the request, thus to avoid this I made sure that the iframe is removed only after the response is over, or you can change the target to "_blank". Thus one of the reason is: when the resource(iframe in my case) that you are writing something in, is removed or deleted before you stop writing to it, the request will be cancelled

我在div标签里面有一个a标签。div有onclick="location='http://mydestination.org/'"和一个标签在href中有相同的URL。这导致目标页面被加载两次，第一次加载被Chrome取消。

我在加载300张图片作为背景图片时遇到了这种情况。我猜一旦第一个超时，它就会取消所有其他的，或者达到最大并发请求。需要一次实现5个

我们曾遇到过类似的问题，Chrome会取消在帧内或iframes内加载内容的请求，但只是间歇性的，这似乎取决于计算机和/或互联网连接的速度。

这些信息已经过时几个月了，但是我从头开始构建了Chromium，在源代码中挖掘了所有可以取消请求的地方，并在所有这些地方设置了断点以进行调试。根据记忆，Chrome会取消请求的地方只有:

The DOM element that caused the request to be made got deleted (i.e. an IMG is being loaded, but before the load happened, you deleted the IMG node) You did something that made loading the data unnecessary. (i.e. you started loading a iframe, then changed the src or overwrite the contents) There are lots of requests going to the same server, and a network problem on earlier requests showed that subsequent requests weren't going to work (DNS lookup error, earlier (same) request resulted e.g. HTTP 400 error code, etc)

在我们的例子中，我们最终追踪到一个试图将HTML附加到另一个帧的帧，这有时发生在目标帧加载之前。一旦您接触到iframe的内容，它就不能再将资源加载到其中(它如何知道将资源放在哪里?)，因此它会取消请求。

我也遇到过同样的问题，在我们的代码深处，我们有这样的伪代码:

创建iframe 加载iframe提交一个表单 2秒后，移除iframe

thus, when the server takes more than 2 seconds to respond the iframe to which the server was writing the response to, was removed, but the response was still to be written , but there was no iframe to write , thus chrome cancelled the request, thus to avoid this I made sure that the iframe is removed only after the response is over, or you can change the target to "_blank". Thus one of the reason is: when the resource(iframe in my case) that you are writing something in, is removed or deleted before you stop writing to it, the request will be cancelled

如果你使用了一些基于可观察对象的HTTP请求，比如Angular(2+)中内置的那些请求，那么当可观察对象被取消时，HTTP请求也可以被取消(当你使用RxJS 6 switchMap操作符合并流时很常见的事情)。在大多数情况下，如果您想要完成请求，使用mergeMap操作符就足够了。