Javascript XMLHttpRequest 抛出 InvalidSateError 说“必须打开对象状态”
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XMLHttpRequest throwing InvalidSateError saying "Object state must be opened"
提问by SachinGutte
The code -
编码 -
"use strict";
var AJAX = function (params) {
this.server ={};
this.url = params.url;
this.method = params.method;
this.dataType = params.dataType;
this.formData = params.formData;
this.init = function(){
if(typeof XMLHttpRequest != 'undefined'){
this.server = new XMLHttpRequest();
this.server.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
this.server.setRequestHeader('Content-length', this.formData.length);
this.server.setRequestHeader('Connection', 'close');
console.log("XMLHttpRequest created.");
return true;
}
};
this.send = function(){
if(this.init()){
this.server.open(this.method, this.url, true);
this.server.send(this.formData);
}
};
};
It is throwing following error :
它抛出以下错误：
Error in event handler for contextMenus: InvalidStateError: Failed to execute 'setRequestHeader' on 'XMLHttpRequest': The object's state must be OPENED.
How it's being used -
它是如何使用的 -
var data = new FormData();
data.append('user', 'sachin');
var params = {
url : 'example.com',
method : 'post',
dataType: 'json',
formData : data
};
var backgroundWindow = chrome.extension.getBackgroundPage();
var ajax = new backgroundWindow.AJAX(params);
ajax.send();
I can't seem to figure out what's the reason behind.
我似乎无法弄清楚背后的原因是什么。
回答by UltraInstinct
The error is straight forward:
错误很简单：
Error in event handler for contextMenus: InvalidStateError: Failed to execute 'setRequestHeader' on 'XMLHttpRequest': The object's state must be OPENED.
contextMenus 的事件处理程序出错：InvalidStateError：无法在“XMLHttpRequest”上执行“setRequestHeader”：对象的状态必须为 OPENED。
You need to call .open(..)before setting the request headers.
您需要.open(..)在设置请求标头之前调用。
Given your code, I believe the best way would be to move the call to open in the init(..)function.
鉴于您的代码，我相信最好的方法是将调用移动到init(..)函数中的open 。
var AJAX = function (params) {
this.server ={};
this.url = params.url;
this.method = params.method;
this.dataType = params.dataType;
this.formData = params.formData;
this.init = function(){
if(typeof XMLHttpRequest != 'undefined'){
this.server = new XMLHttpRequest();
//Open first, before setting the request headers.
this.server.open(this.method, this.url, true);
//Now set the request headers.
this.server.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
//this.server.setRequestHeader('Content-length', this.formData.length);
//this.server.setRequestHeader('Connection', 'close');
console.log("XMLHttpRequest created.");
return true;
}
};
this.send = function(){
if(this.init()){
this.server.send(this.formData);
}
};
};
回答by Ganesh Kamath - 'Code Frenzy'
You probably need to open the connection after the XMLHttpRequestcall and before the setRequestHeadercall Instead of:
您可能需要在XMLHttpRequest通话之后和通话之前打开连接，setRequestHeader而不是：
this.server = new XMLHttpRequest();
this.server.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
i think you need to do:
我认为你需要这样做：
this.server = new XMLHttpRequest();
this.server.open(this.method, this.url, true);
this.server.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
also make sure you remove this line in the init(), like you have done above.
还要确保删除 中的这一行init()，就像上面所做的那样。
