无法从应用程序POST到SlackIncomingWebhook

我可以使用curl发布到我的Slack Incoming Webhook:

curl -X POST -H 'Content-type: application/json' --data '{"text":"Hello world"}' https://hooks.slack.com/services/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

但是当我使用时

$.ajax({
    url: "https://hooks.slack.com/services/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",
    data: '{"text": "Hello world"}',
    type: "POST",
    contentType: "application/json"
})
    .done(function (reply) {
        console.log("POST to Slack succeeded")
    })
    .fail(function (xhr, status, errorThrown) {
        console.log("Error in POST to Slack: " + errorThrown.toString())
    })

在我的应用程序的localhost:8090服务的页面中,我收到错误:

jquery.js:9536 OPTIONS https://hooks.slack.com/services/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 
400 (Bad Request)
XMLHttpRequest cannot load https://hooks.slack.com/services/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. 
Response for preflight has invalid HTTP status code 400

通常,我页面上的POST将转到我的服务器,该服务器为页面提供服务.所以我认为我的困惑与理解Webhooks如何工作有关.我认为同源政策禁止我发布到任意网址.但是为什么curl命令工作,我如何让我的页面做curl的工作呢？

我是否需要从服务器发送POST,而不是从客户端浏览器发送？

我从Slack的Ben J那里得到了答案.我所要做的就是删除线

contentType: "application/json"

来自Slack团队的精彩,快速的帮助.非常感激.