纯JS

在纯JS中，这要简单得多

foo.onsubmit = e=> {
  e.preventDefault();
  fetch(foo.action,{method:'post', body: new FormData(foo)});
}

foo.onsubmit = e=> { e.preventDefault（）; fetch（foo.action，{method：'post'， body： new FormData（foo）}）; } <form name=“foo” action=“form.php” method=“POST” id=“foo”> <label for=“bar”>A bar</label> <输入 id=“bar” 名称=“bar” 类型=“文本” 值=“” /> <输入类型=“提交”值=“发送” /> </form>

你可以使用serialize。下面是一个例子。

$("#submit_btn").click(function(){
    $('.error_status').html();
        if($("form#frm_message_board").valid())
        {
            $.ajax({
                type: "POST",
                url: "<?php echo site_url('message_board/add');?>",
                data: $('#frm_message_board').serialize(),
                success: function(msg) {
                    var msg = $.parseJSON(msg);
                    if(msg.success=='yes')
                    {
                        return true;
                    }
                    else
                    {
                        alert('Server error');
                        return false;
                    }
                }
            });
        }
        return false;
    });

HTML:

    <form name="foo" action="form.php" method="POST" id="foo">
        <label for="bar">A bar</label>
        <input id="bar" class="inputs" name="bar" type="text" value="" />
        <input type="submit" value="Send" onclick="submitform(); return false;" />
    </form>

JavaScript:

   function submitform()
   {
       var inputs = document.getElementsByClassName("inputs");
       var formdata = new FormData();
       for(var i=0; i<inputs.length; i++)
       {
           formdata.append(inputs[i].name, inputs[i].value);
       }
       var xmlhttp;
       if(window.XMLHttpRequest)
       {
           xmlhttp = new XMLHttpRequest;
       }
       else
       {
           xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
       }
       xmlhttp.onreadystatechange = function()
       {
          if(xmlhttp.readyState == 4 && xmlhttp.status == 200)
          {

          }
       }
       xmlhttp.open("POST", "insert.php");
       xmlhttp.send(formdata);
   }

这是一篇非常好的文章，包含了关于jQuery表单提交你需要知道的一切。

文章摘要:

简单HTML表单提交

HTML:

<form action="path/to/server/script" method="post" id="my_form">
    <label>Name</label>
    <input type="text" name="name" />
    <label>Email</label>
    <input type="email" name="email" />
    <label>Website</label>
    <input type="url" name="website" />
    <input type="submit" name="submit" value="Submit Form" />
    <div id="server-results"><!-- For server results --></div>
</form>

JavaScript:

$("#my_form").submit(function(event){
    event.preventDefault(); // Prevent default action
    var post_url = $(this).attr("action"); // Get the form action URL
    var request_method = $(this).attr("method"); // Get form GET/POST method
    var form_data = $(this).serialize(); // Encode form elements for submission

    $.ajax({
        url : post_url,
        type: request_method,
        data : form_data
    }).done(function(response){ //
        $("#server-results").html(response);
    });
});

HTML Multipart/ Form -data表单提交

要将文件上传到服务器，我们可以使用XMLHttpRequest2提供的FormData接口，该接口构造一个FormData对象，可以使用jQuery Ajax轻松地将其发送到服务器。

HTML:

<form action="path/to/server/script" method="post" id="my_form">
    <label>Name</label>
    <input type="text" name="name" />
    <label>Email</label>
    <input type="email" name="email" />
    <label>Website</label>
    <input type="url" name="website" />
    <input type="file" name="my_file[]" /> <!-- File Field Added -->
    <input type="submit" name="submit" value="Submit Form" />
    <div id="server-results"><!-- For server results --></div>
</form>

JavaScript:

$("#my_form").submit(function(event){
    event.preventDefault(); // Prevent default action
    var post_url = $(this).attr("action"); // Get form action URL
    var request_method = $(this).attr("method"); // Get form GET/POST method
    var form_data = new FormData(this); // Creates new FormData object
    $.ajax({
        url : post_url,
        type: request_method,
        data : form_data,
        contentType: false,
        cache: false,
        processData: false
    }).done(function(response){ //
        $("#server-results").html(response);
    });
});

我希望这能有所帮助。

我使用这个简单的一行代码多年没有问题(它需要jQuery):

<script src="http://malsup.github.com/jquery.form.js"></script> 
<script type="text/javascript">
    function ap(x,y) {$("#" + y).load(x);};
    function af(x,y) {$("#" + x ).ajaxSubmit({target: '#' + y});return false;};
</script>

这里ap()表示Ajax页面，af()表示Ajax表单。在表单中，只需调用af()函数即可将表单发送到URL，并在所需的HTML元素上加载响应。

<form id="form_id">
    ...
    <input type="button" onclick="af('form_id','load_response_id')"/>
</form>
<div id="load_response_id">this is where response will be loaded</div>

在你的php文件中输入:

$content_raw = file_get_contents("php://input"); // THIS IS WHAT YOU NEED
$decoded_data = json_decode($content_raw, true); // THIS IS WHAT YOU NEED
$bar = $decoded_data['bar']; // THIS IS WHAT YOU NEED
$time = $decoded_data['time'];
$hash = $decoded_data['hash'];
echo "You have sent a POST request containing the bar variable with the value $bar";

在你的js文件中发送一个带有数据对象的ajax

var data = { 
    bar : 'bar value',
    time: calculatedTimeStamp,
    hash: calculatedHash,
    uid: userID,
    sid: sessionID,
    iid: itemID
};

$.ajax({
    method: 'POST',
    crossDomain: true,
    dataType: 'json',
    crossOrigin: true,
    async: true,
    contentType: 'application/json',
    data: data,
    headers: {
        'Access-Control-Allow-Methods': '*',
        "Access-Control-Allow-Credentials": true,
        "Access-Control-Allow-Headers" : "Access-Control-Allow-Headers, Origin, X-Requested-With, Content-Type, Accept, Authorization",
        "Access-Control-Allow-Origin": "*",
        "Control-Allow-Origin": "*",
        "cache-control": "no-cache",
        'Content-Type': 'application/json'
    },
    url: 'https://yoururl.com/somephpfile.php',
    success: function(response){
        console.log("Respond was: ", response);
    },
    error: function (request, status, error) {
        console.log("There was an error: ", request.responseText);
    }
  })

或者保持表单提交的原样。只有当您希望发送带有计算附加内容的修改过的请求，而不仅仅是一些由客户机输入的表单数据时，才需要这种方法。例如哈希、时间戳、用户id、会话id等等。