公众号设置授权回调页面域名: example.com
example.com/get_openid.php
<?php
$appid = '***';
$appsecret = '***';
$code = $_GET[ 'code' ];
if ( !$code ) {
$redirect_uri_web = str_replace( '&', '@@@', $_GET[ 'redirect_uri' ] );
$redirect_uri = urlencode( 'http://example.com/get_openid.php' ).'?redirect_uri_web='.$redirect_uri_web;
$url = "https://open.weixin.qq.com/connect/oauth2/authorize?appid=$appid&redirect_uri=$redirect_uri&response_type=code&scope=snsapi_base&state=STATE#wechat_redirect";
header( "Location: $url" );
exit();
}
if ( $code ) {
$url = 'https://api.weixin.qq.com/sns/oauth2/access_token';
$params = [ 'appid'=>$appid, 'secret'=>$appsecret, 'code'=>$code, 'grant_type'=>'authorization_code' ];
$result = do_get( $url, $params );
$result = json_decode( $result, true );
$redirect_uri_web = str_replace( '@@@', '&', $_GET[ 'redirect_uri_web' ] );
$redirect_uri_web = $redirect_uri_web. ( strchr( $redirect_uri_web, '?' )? '&':'?' ) .'openid='.$result[ 'openid' ];
header( "Location: $redirect_uri_web" );
exit();
}
function do_get( $url, $params ) {
$url = "{$url}?" . http_build_query ( $params );
$ch = curl_init ();
curl_setopt ( $ch, CURLOPT_URL, $url );
curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, 1 );
curl_setopt ( $ch, CURLOPT_CUSTOMREQUEST, 'GET' );
curl_setopt ( $ch, CURLOPT_TIMEOUT, 60 );
curl_setopt ( $ch, CURLOPT_POSTFIELDS, $params );
$result = curl_exec ( $ch );
curl_close ( $ch );
return $result;
}
使用:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>获取openId</title>
</head>
<body>
<script>
if (!getQueryVariable('openid')) {
const redirect_uri = encodeURIComponent(location.href + '?a=1&b=2');
const url = 'http://example.com/get_openid.php?redirect_uri=' + redirect_uri;
window.location.href = url;
}else{
console.log(getQueryVariable('openid'));
}
function getQueryVariable(variable) {
var query = window.location.search.substring(1);
var vars = query.split('&');
for (var i = 0; i < vars.length; i++) {
var pair = vars[i].split('=');
if (pair[0] == variable) {
return pair[1];
}
}
return false;
}
</script>
</body>
</html>
