{"id":12172,"date":"2023-11-28T22:45:41","date_gmt":"2023-11-28T14:45:41","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=12172"},"modified":"2023-11-29T23:27:48","modified_gmt":"2023-11-29T15:27:48","slug":"javascript-zhong-readystate-04","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/11\/28\/javascript-zhong-readystate-04\/","title":{"rendered":"JavaScript \u4e2d readystate 0~4\uff1f"},"content":{"rendered":"

\u5728 JavaScript \u4e2d\uff0creadyState<\/code> \u662f XMLHttpRequest \u5bf9\u8c61\u7684\u4e00\u4e2a\u5c5e\u6027\uff0c\u8868\u793a\u8bf7\u6c42\u7684\u72b6\u6001\u3002\u5b83\u7684\u53d6\u503c\u8303\u56f4\u662f\u4ece 0 \u5230 4\uff0c\u5bf9\u5e94\u4e0d\u540c\u7684\u72b6\u6001\uff1a<\/p>\n

    \n
  1. \n

    readyState<\/code> \u4e3a 0\uff08UNSENT\uff09<\/strong>\uff1a\u8868\u793a XMLHttpRequest \u5bf9\u8c61\u5df2\u521b\u5efa\uff0c\u4f46\u5c1a\u672a\u8c03\u7528 open()<\/code> \u65b9\u6cd5\u3002\u4e5f\u5c31\u662f\u8bf7\u6c42\u8fd8\u6ca1\u6709\u521d\u59cb\u5316\u3002<\/p>\n<\/li>\n

  2. \n

    readyState<\/code> \u4e3a 1\uff08OPENED\uff09<\/strong>\uff1a\u8868\u793a open()<\/code> \u65b9\u6cd5\u5df2\u7ecf\u88ab\u8c03\u7528\uff0c\u4f46 send()<\/code> \u65b9\u6cd5\u672a\u88ab\u8c03\u7528\u3002\u8bf7\u6c42\u5df2\u7ecf\u521d\u59cb\u5316\u3002<\/p>\n<\/li>\n

  3. \n

    readyState<\/code> \u4e3a 2\uff08HEADERS_RECEIVED\uff09<\/strong>\uff1a\u8868\u793a send()<\/code> \u65b9\u6cd5\u5df2\u7ecf\u88ab\u8c03\u7528\uff0c\u5e76\u4e14\u5934\u90e8\u548c\u72b6\u6001\u5df2\u7ecf\u53ef\u83b7\u5f97\uff0c\u4f46\u54cd\u5e94\u4f53\u8fd8\u4e0d\u53ef\u7528\u3002<\/p>\n<\/li>\n

  4. \n

    readyState<\/code> \u4e3a 3\uff08LOADING\uff09<\/strong>\uff1a\u8868\u793a\u54cd\u5e94\u4f53\u6b63\u5728\u4e0b\u8f7d\uff0cresponseText<\/code> \u5c5e\u6027\u5df2\u7ecf\u5305\u542b\u90e8\u5206\u6570\u636e\u3002<\/p>\n<\/li>\n

  5. \n

    readyState<\/code> \u4e3a 4\uff08DONE\uff09<\/strong>\uff1a\u8868\u793a\u8bf7\u6c42\u5df2\u7ecf\u5b8c\u6210\uff0c\u4e14\u54cd\u5e94\u5df2\u5c31\u7eea\u3002\u6b64\u65f6\u53ef\u4ee5\u901a\u8fc7 responseText<\/code> \u6216 responseXML<\/code> \u83b7\u53d6\u5b8c\u6574\u7684\u54cd\u5e94\u6570\u636e\u3002<\/p>\n<\/li>\n<\/ol>\n

    \u8fd9\u4e9b\u72b6\u6001\u503c\u7528\u4e8e\u76d1\u542c\u548c\u63a7\u5236 XMLHttpRequest \u5bf9\u8c61\u7684\u8bf7\u6c42\u8fc7\u7a0b\uff0c\u901a\u5e38\u4e0e\u4e8b\u4ef6 onreadystatechange<\/code> \u7ed3\u5408\u4f7f\u7528\uff0c\u4ee5\u4fbf\u5728\u4e0d\u540c\u72b6\u6001\u4e0b\u6267\u884c\u76f8\u5e94\u7684\u64cd\u4f5c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

    \u5728 JavaScript \u4e2d\uff0creadyState \u662f XMLHttpRequest \u5bf9\u8c61\u7684\u4e00\u4e2a\u5c5e\u6027\uff0c\u8868\u793a\u8bf7\u6c42 […]<\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[115],"tags":[],"class_list":["post-12172","post","type-post","status-publish","format-standard","hentry","category-javascript"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/12172","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=12172"}],"version-history":[{"count":2,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/12172\/revisions"}],"predecessor-version":[{"id":13594,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/12172\/revisions\/13594"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=12172"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=12172"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=12172"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}