在 php 函数之后从 javascript 获取隐藏字段值

Question

我的代码有一些问题。我的页面中有一个 Javascript 函数和一个填充隐藏字段的 PHP 函数。当我从 Javascript 读取隐藏字段时，读取的值不是当前值。好像没有刷新。我需要帮助，拜托。每一个提示都非常感谢！谢谢！

这是我的 Javascript 代码：

var username = document.getElementById('user').value;
checkUserName(username);

var opennextpage = document.getElementById('hidden_field_openpage').value;

if (opennextpage == 'YES'){
// open next page
}
else{
alert('Can't open page');
}

我通过 AJAX 调用 PHP 页面是这样的：

function checkUserName(username){
    var strURL  = "js/ax_checkusername.php?user="+ username; 
    var req = getXMLHTTP();

    if (req)
    {
        req.onreadystatechange = function()
        {
            if (req.readyState == 4)
            {
                // only if "OK"
                if (req.status == 200)
                {
                    document.getElementById('hidden_field_openpage').value = req.responseText;
                } 
                else 
                {
                    alert("There was a problem while using XMLHTTP:\n" + req.statusText);
                }
            }
        }
    }
    req.open("GET", strURL, true);
    req.setRequestHeader("If-Modified-Since", "Sat, 1 Jan 2000 00:00:00 GMT");
    req.send(null);
}

Answer 1

你为什么不把两者结合起来，像这样：

function checkUserName(username){
    var strURL  = "js/ax_checkusername.php?user="+ username; 
    var req = getXMLHTTP();

    if (req)
    {
        req.onreadystatechange = function()
        {
            if (req.readyState == 4)
            {
                // only if "OK"
                if (req.status == 200)
                {
                   if (req.responseText == 'YES'){
// open next page here itself
}
else{
alert('Can\'t open page');
};
                } 
                else 
                {
                    alert("There was a problem while using XMLHTTP:\n" + req.statusText);
                }
            }
        }
    }
    req.open("GET", strURL, true);
    req.setRequestHeader("If-Modified-Since", "Sat, 1 Jan 2000 00:00:00 GMT");
    req.send(null);
}

然后调用 checkUserName(username) ?

在 php 函数之后从 javascript 获取隐藏字段值

Get hidden field value from javascript after php function

javascript

php

ajax

hidden-field