我想在JavaScript中使用XMLHttpRequest发送一些数据。
假设我在HTML中有以下表单:
<form name="inputform" action="somewhere" method="post">
<input type="hidden" value="person" name="user">
<input type="hidden" value="password" name="pwd">
<input type="hidden" value="place" name="organization">
<input type="hidden" value="key" name="requiredkey">
</form>
如何在JavaScript中使用XMLHttpRequest编写等效内容?
当前回答
下面的代码演示了如何做到这一点。
var http = new XMLHttpRequest();
var url = 'get_data.php';
var params = 'orem=ipsum&name=binny';
http.open('POST', url, true);
//Send the proper header information along with the request
http.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
http.onreadystatechange = function() {//Call a function when the state changes.
if(http.readyState == 4 && http.status == 200) {
alert(http.responseText);
}
}
http.send(params);
如果你有/创建一个对象，你可以用下面的代码把它转换成参数，即:
var params = new Object();
params.myparam1 = myval1;
params.myparam2 = myval2;
// Turn the data object into an array of URL-encoded key/value pairs.
let urlEncodedData = "", urlEncodedDataPairs = [], name;
for( name in params ) {
urlEncodedDataPairs.push(encodeURIComponent(name)+'='+encodeURIComponent(params[name]));
}
其他回答
最小限度地使用FormData来提交AJAX请求
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="X-UA-Compatible" content="IE=Edge, chrome=1"/>
<script>
"use strict";
function submitForm(oFormElement)
{
var xhr = new XMLHttpRequest();
xhr.onload = function(){ alert (xhr.responseText); } // success case
xhr.onerror = function(){ alert (xhr.responseText); } // failure case
xhr.open (oFormElement.method, oFormElement.action, true);
xhr.send (new FormData (oFormElement));
return false;
}
</script>
</head>
<body>
<form method="post" action="somewhere" onsubmit="return submitForm(this);">
<input type="hidden" value="person" name="user" />
<input type="hidden" value="password" name="pwd" />
<input type="hidden" value="place" name="organization" />
<input type="hidden" value="key" name="requiredkey" />
<input type="submit" value="post request"/>
</form>
</body>
</html>
讲话
This does not fully answer the OP question because it requires the user to click in order to submit the request. But this may be useful to people searching for this kind of simple solution. This example is very simple and does not support the GET method. If you are interesting by more sophisticated examples, please have a look at the excellent MDN documentation. See also similar answer about XMLHttpRequest to Post HTML Form. Limitation of this solution: As pointed out by Justin Blank and Thomas Munk (see their comments), FormData is not supported by IE9 and lower, and default browser on Android 2.3.
这帮助我，因为我想只使用xmlHttpRequest和post对象作为表单数据:
function sendData(data) {
var XHR = new XMLHttpRequest();
var FD = new FormData();
// Push our data into our FormData object
for(name in data) {
FD.append(name, data[name]);
}
// Set up our request
XHR.open('POST', 'https://example.com/cors.php');
// Send our FormData object; HTTP headers are set automatically
XHR.send(FD);
}
https://developer.mozilla.org/en-US/docs/Learn/HTML/Forms/Sending_forms_through_JavaScript
我也遇到过类似的问题，使用相同的帖子和这个链接，我已经解决了我的问题。
var http = new XMLHttpRequest();
var url = "MY_URL.Com/login.aspx";
var params = 'eid=' +userEmailId+'&pwd='+userPwd
http.open("POST", url, true);
// Send the proper header information along with the request
//http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
//http.setRequestHeader("Content-Length", params.length);// all browser wont support Refused to set unsafe header "Content-Length"
//http.setRequestHeader("Connection", "close");//Refused to set unsafe header "Connection"
// Call a function when the state
http.onreadystatechange = function() {
if(http.readyState == 4 && http.status == 200) {
alert(http.responseText);
}
}
http.send(params);
此链接已完成信息。
下面的代码演示了如何做到这一点。
var http = new XMLHttpRequest();
var url = 'get_data.php';
var params = 'orem=ipsum&name=binny';
http.open('POST', url, true);
//Send the proper header information along with the request
http.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
http.onreadystatechange = function() {//Call a function when the state changes.
if(http.readyState == 4 && http.status == 200) {
alert(http.responseText);
}
}
http.send(params);
如果你有/创建一个对象，你可以用下面的代码把它转换成参数，即:
var params = new Object();
params.myparam1 = myval1;
params.myparam2 = myval2;
// Turn the data object into an array of URL-encoded key/value pairs.
let urlEncodedData = "", urlEncodedDataPairs = [], name;
for( name in params ) {
urlEncodedDataPairs.push(encodeURIComponent(name)+'='+encodeURIComponent(params[name]));
}
下面是一个完整的应用程序json解决方案:
// Input values will be grabbed by ID
<input id="loginEmail" type="text" name="email" placeholder="Email">
<input id="loginPassword" type="password" name="password" placeholder="Password">
// return stops normal action and runs login()
<button onclick="return login()">Submit</button>
<script>
function login() {
// Form fields, see IDs above
const params = {
email: document.querySelector('#loginEmail').value,
password: document.querySelector('#loginPassword').value
}
const http = new XMLHttpRequest()
http.open('POST', '/login')
http.setRequestHeader('Content-type', 'application/json')
http.send(JSON.stringify(params)) // Make sure to stringify
http.onload = function() {
// Do whatever with response
alert(http.responseText)
}
}
</script>
确保你的后端API可以解析JSON。
例如，在Express JS中:
import bodyParser from 'body-parser'
app.use(bodyParser.json())
