尝试使用JSON消息和AJAX将图像从PHP数组加载到javaScript数组。使用函数buildImage()将数组中的第一张图像加载到div内容中。使用onclick将图像更改为数组中的下一个图像。我是AJAX和JSON的新手。JSON消息和javaScript数组之间的转换是我的主要问题。
PHP<?php
include("mysqlconnect.php");
$select_query = "SELECT `ImagesPath` FROM `offerstbl` ORDER by `ImagesId` DESC";
$sql = mysql_query($select_query) or die(mysql_error());
$data = array();
while($row = mysql_fetch_array($sql,MYSQL_BOTH)){
$data[] = $row['ImagesPath'];
}
echo $images = json_encode($data);
?>
客户端脚本
<script>
var images = JSON.parse(xmlhttp.responseText);
function importJson(str) {
// console.log(typeof xmlhttp.responseText);
if (str=="") {
document.getElementById("content").innerHTML="";
return;
}
if (window.XMLHttpRequest) {
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
} else { // code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function() {
if (xmlhttp.readyState==4)
{
images = JSON.parse(xmlhttp.responseText);
document.getElementById("content").innerHTML=images;
}
}
xmlhttp.open("GET","http://content.php");
xmlhttp.send();
}
function buildImage(src) {
var img = document.createElement('img')
img.src = src
alert("1");
document.getElementById('content').appendChild(img);
}
for (var i = 0; i < images.length; i++) {
buildImage(images[i]);
}
</script>
</head>
<body onload= "importJson();" onload= "buildImage();" >
<div class="contents" id="content" onclick="buildImage()"></div>
</body>
在xmlhttp.responseText准备好之前您呼叫JSON.parse(xmlhttp.responseText)
响应就绪时调用
if (xmlhttp.readyState==4)
{
images = JSON.parse(xmlhttp.responseText);
document.getElementById("content").innerHTML=images;
}
AJAX是异步的。您必须解析JSON并在onreadystatechange函数中运行for循环
<script>
function importJson(str) {
// console.log(typeof xmlhttp.responseText);
if (str=="") {
document.getElementById("content").innerHTML="";
return;
}
if (window.XMLHttpRequest) {
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
} else { // code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function() {
if (xmlhttp.readyState==4 && xmlhttp.status == 200)
{
images = JSON.parse(xmlhttp.responseText);
for (var i = 0; i < images.length; i++) {
buildImage(images[i]);
}
}
}
xmlhttp.open("GET","http:/content.php");
xmlhttp.send();
}
function buildImage(src) {
var img = document.createElement('img')
img.src = src
alert("1");
document.getElementById('content').appendChild(img);
}
</script>
</head>
<body onload= "importJson();" >
<div class="contents" id="content" onclick="buildImage()"></div>
</body>