您可以使用DHTML动态添加表单，然后提交。

@Aaron回答的一个简单而快速的实现：

document.body.innerHTML += '<form id="dynForm" action="http://example.com/" method="post"><input type="hidden" name="q" value="a"></form>';
document.getElementById("dynForm").submit();

当然，您应该使用JavaScript框架，如Prototype或jQuery。。。

在表单中动态创建＜input＞并提交

/**
 * sends a request to the specified url from a form. this will change the window location.
 * @param {string} path the path to send the post request to
 * @param {object} params the parameters to add to the url
 * @param {string} [method=post] the method to use on the form
 */

function post(path, params, method='post') {

  // The rest of this code assumes you are not using a library.
  // It can be made less verbose if you use one.
  const form = document.createElement('form');
  form.method = method;
  form.action = path;

  for (const key in params) {
    if (params.hasOwnProperty(key)) {
      const hiddenField = document.createElement('input');
      hiddenField.type = 'hidden';
      hiddenField.name = key;
      hiddenField.value = params[key];

      form.appendChild(hiddenField);
    }
  }

  document.body.appendChild(form);
  form.submit();
}

例子：

post('/contact/', {name: 'Johnny Bravo'});

编辑：既然这件事得到了如此多的支持，我猜人们会大量复制粘贴这件事。所以我添加了hasOwnProperty检查，以修复任何意外的错误。

使用此答案中提供的createElement函数，这是必要的，因为IE在使用document.createElement正常创建的元素上使用name属性时会中断：

function postToURL(url, values) {
    values = values || {};

    var form = createElement("form", {action: url,
                                      method: "POST",
                                      style: "display: none"});
    for (var property in values) {
        if (values.hasOwnProperty(property)) {
            var value = values[property];
            if (value instanceof Array) {
                for (var i = 0, l = value.length; i < l; i++) {
                    form.appendChild(createElement("input", {type: "hidden",
                                                             name: property,
                                                             value: value[i]}));
                }
            }
            else {
                form.appendChild(createElement("input", {type: "hidden",
                                                         name: property,
                                                         value: value}));
            }
        }
    }
    document.body.appendChild(form);
    form.submit();
    document.body.removeChild(form);
}

我的解决方案将对深度嵌套的对象进行编码，这与@RakeshPai目前接受的解决方案不同。

它使用“qs”npm库及其字符串函数将嵌套对象转换为参数。

这段代码可以很好地与Rails后端配合使用，尽管您应该能够通过修改传递给stringify的选项来修改它，使其能够与您需要的任何后端配合使用。Rails要求将arrayFormat设置为“括号”。

import qs from "qs"

function normalPost(url, params) {
  var form = document.createElement("form");
  form.setAttribute("method", "POST");
  form.setAttribute("action", url);

  const keyValues = qs
    .stringify(params, { arrayFormat: "brackets", encode: false })
    .split("&")
    .map(field => field.split("="));

  keyValues.forEach(field => {
    var key = field[0];
    var value = field[1];
    var hiddenField = document.createElement("input");
    hiddenField.setAttribute("type", "hidden");
    hiddenField.setAttribute("name", key);
    hiddenField.setAttribute("value", value);
    form.appendChild(hiddenField);
  });
  document.body.appendChild(form);
  form.submit();
}

例子：

normalPost("/people/new", {
      people: [
        {
          name: "Chris",
          address: "My address",
          dogs: ["Jordan", "Elephant Man", "Chicken Face"],
          information: { age: 10, height: "3 meters" }
        },
        {
          name: "Andrew",
          address: "Underworld",
          dogs: ["Doug", "Elf", "Orange"]
        },
        {
          name: "Julian",
          address: "In a hole",
          dogs: ["Please", "Help"]
        }
      ]
    });

生成这些Rails参数：

{"authenticity_token"=>"...",
 "people"=>
  [{"name"=>"Chris", "address"=>"My address", "dogs"=>["Jordan", "Elephant Man", "Chicken Face"], "information"=>{"age"=>"10", "height"=>"3 meters"}},
   {"name"=>"Andrew", "address"=>"Underworld", "dogs"=>["Doug", "Elf", "Orange"]},
   {"name"=>"Julian", "address"=>"In a hole", "dogs"=>["Please", "Help"]}]}

这是基于beauSD使用jQuery的代码。它得到了改进，因此可以递归地处理对象。

function post(url, params, urlEncoded, newWindow) {
    var form = $('<form />').hide();
    form.attr('action', url)
        .attr('method', 'POST')
        .attr('enctype', urlEncoded ? 'application/x-www-form-urlencoded' : 'multipart/form-data');
    if(newWindow) form.attr('target', '_blank');

    function addParam(name, value, parent) {
        var fullname = (parent.length > 0 ? (parent + '[' + name + ']') : name);
        if(value instanceof Object) {
            for(var i in value) {
                addParam(i, value[i], fullname);
            }
        }
        else $('<input type="hidden" />').attr({name: fullname, value: value}).appendTo(form);
    };

    addParam('', params, '');

    $('body').append(form);
    form.submit();
}