FormData 表单数据对象，这是在HTML5中新增的一个API，他能以表单对象做参数，自动的将表单的数据打包，当ajax发送数据是，发送FormData内的表单数据给后端即可
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<script>
function fd(){
var fdate = document.getElementById('fdate');
var fd = new FormData(fdate);
var xhr = new XMLHttpRequest();
xhr.open('post','10.php',true);
xhr.send(fd);
xhr.onreadystatechange = function(){
if(this.readyState == 4){
document.getElementById('desc').innerHTML = this.responseText;
}
} }
</script>
<body>
<form id="fdate" >
user:<input type="text" name="user"> <br><br>
age:<input type="text" name="age"> <br><br>
sex:<input type="text" name="sex"> <br><br>
QQ:<input type="text" name="QQ"> <br><br>
<input type="button" value="Go" onclick="fd();">
</form>
<p id="desc"></p>
</body>
</html>
效果如下所示：
这样比传统的拼接方法简单多了，当然他还有另外一种用法，如下所示：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<script>
function fd(){
var fdate = document.getElementById('fdate');
var fd = new FormData(fdate);
var fd2 = new FormData();
var xhr = new XMLHttpRequest();
xhr.open('post','10.php',true);
//xhr.send(fd);
fd2.append('user','leigood');
fd2.append('age','18');
xhr.send(fd2);
xhr.onreadystatechange = function(){
if(this.readyState == 4){
document.getElementById('desc').innerHTML = this.responseText;
}
} }
</script>
<body>
<form id="fdate" >
user:<input type="text" name="user"> <br><br>
age:<input type="text" name="age"> <br><br>
sex:<input type="text" name="sex"> <br><br>
QQ:<input type="text" name="QQ"> <br><br>
<input type="button" value="Go" onclick="fd();">
</form>
<p id="desc"></p>
</body>
</html>
效果如下所示：
