嗨，我有一些 ajax 编码，其中 if 条件根本不工作，每当程序执行 else 语句时，即使程序满足 if 语句也只能工作。
<script type="text/javascript">
function CheckDetails()
{
var http = false;
if (navigator.appName == "Microsoft Internet Explorer") {
http = new ActiveXObject("Microsoft.XMLHTTP");
} else {
http = new XMLHttpRequest();
}
var rid = document.new_booking.ph_number.value;
http.onreadystatechange = function() {
if (http.readyState == 4) {
var str_d = http.responseText;
if (str_d == "no") {
document.getElementById('cus_name').focus();
} else {
var str_details = http.responseText;
var arr_details = str_details.split("~");
document.new_booking.cus_name.value = arr_details[0];
document.new_booking.pick_aline1.value = arr_details[1];
document.new_booking.pick_aline2.value = arr_details[2];
document.new_booking.pick_area.value = arr_details[3];
document.new_booking.pick_pincode.value = arr_details[4];
document.new_booking.drop_aline1.focus();
}
}
}
http.open("GET", "ajax.php?evnt=det&rid=" + rid);
http.send();
}
</script>
它的 ajax.php 文件如下
<?php
if ($_GET['evnt'] == 'det') {
$rid = $_GET['rid'];
include("configure.php");
$select = mysql_query("select * from new_booking where ph_number = '$rid'");
$count = mysql_num_rows($select);
if ($count > 0) {
$row = mysql_fetch_array($select);
echo $row['cus_name']
. "~" . $row['pick_aline1']
. "~" . $row['pick_aline2']
. "~" . $row['pick_area']
. "~" . $row['pick_pincode']
. "~" . $row['drop_aline1']
. "~" . $row['drop_aline2']
. "~" . $row['drop_area']
. "~" . $row['drop_pincode'];
} else {
echo "no";
}
}
?>
您可以使用Chrome（或Chromium）打开页面，然后使用内置调试器（Ctrl + Shift + I，"控制台"选项卡）调试JavaScript代码。我想你会在那里看到一些JS错误。
基本上，您的代码工作正常（至少当我从中删除所有数据库访问权限时，因为我没有您的数据库）。
如果您不喜欢Chrome，请使用Firefox和FireBug扩展程序。在"网络"页面上，您可以看到您的 ajax 请求已执行（或未执行）。
如果我不得不猜测，我会说一些空格正在潜入您的 AJAX 响应的某个地方。因为"no "不等于"no"，它总是击中你的else分支。
您可以考虑发回与空格无关的值。你可以重写整个混乱以使用JSON，这将需要更少的两端工作：
// PHP:
if ($_GET['evnt'] == 'det') {
$rid = $_GET['rid'];
include("configure.php");
$select = mysql_query("select * from new_booking where ph_number = '$rid'");
$count = mysql_num_rows($select);
if ($count > 0) {
$row = mysql_fetch_array($select);
// YOU PROBABLY WANT TO WHITELIST WHAT YOU PASS TO JSON_ENCODE
echo json_encode($row);
} else {
echo json_encode([ "error" => "no" ]);
}
}
// js:
http.onreadystatechange = function() {
if (http.readyState == 4) {
var str_d;
try {
str_d = JSON.parse(http.responseText);
} catch(e) {
str_d = false;
}
if (str_d && str_d.error === "no") {
document.getElementById('cus_name').focus();
} else {
document.new_booking.cus_name.value = str_d.pick_aline1;
document.new_booking.pick_aline1.value = str_d.pick_aline2;
document.new_booking.pick_aline2.value = str_d.pick_area;
// etc...
}
}
}
我遇到了类似的问题。这对我有用。
if (str_d.replace(/^'s+|'s+$/g, '') == "no")