微信支付JSAPI为什么返回的是string(105)""这样的空值？

如题，有没遇到这种情况的？

$trade\_type = "JSAPI";

$signA = array(“appid”=>$appid,“mch_id”=>$mch_id,“nonce_str”=>$nonce_str,

“body”=>$body,“out_trade_no”=>$out_trade_no,“total_fee”=>$total_fee,

“spbill_create_ip”=>$spbill_create_ip,“notify_url”=>$notify_url,

“trade_type”=>$trade_type,“openid”=>$openid,“device_info”=>$device_info);

$sign = GetPrePayId_Sign_ASCII_ASC_Encode($signA,$mykey=“”,$isencode=false);

$data  = ‘<xml>’;

$data .= Construct_XmlTagStr(“appid”,$appid);

$data .= Construct_XmlTagStr(“mch_id”,$mch_id);

$data .= Construct_XmlTagStr(“nonce_str”,$nonce_str);

$data .= Construct_XmlTagStr(“body”,$body);

$data .= Construct_XmlTagStr(“out_trade_no”,$out_trade_no);

$data .= Construct_XmlTagStr(“total_fee”,$total_fee);

$data .= Construct_XmlTagStr(“spbill_create_ip”,$spbill_create_ip);

$data .= Construct_XmlTagStr(“notify_url”,$notify_url);

$data .= Construct_XmlTagStr(“trade_type”,$trade_type);

$data .= Construct_XmlTagStr(“openid”,$openid);

$data .= Construct_XmlTagStr(“device_info”,$device_info);

$data .= Construct_XmlTagStr(“sign”,$sign);

$data .= “</xml>”;

$url = “https://api.mch.weixin.qq.com/pay/unifiedorder”;

$res = WxPayCurlPost($url,$data);

function WxPayCurlPost($url,$xml_data,$useCert=false){//post推送

$ch = curl_init();

curl_setopt ( $ch, CURLOPT_URL, $url );

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);

curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);

if($useCert){

//设置证书

//使用证书：cert 与 key 分别属于两个.pem文件

//证书文件请放入服务器的非web目录下

$sslCertPath = “”;

$sslKeyPath = “”;

curl_setopt($ch,CURLOPT_SSLCERTTYPE,‘PEM’);

curl_setopt($ch,CURLOPT_SSLCERT, $sslCertPath);

curl_setopt($ch,CURLOPT_SSLKEYTYPE,‘PEM’);

curl_setopt($ch,CURLOPT_SSLKEY, $sslKeyPath);

}

curl_setopt ( $ch, CURLOPT_POST, true );

curl_setopt ( $ch, CURLOPT_POSTFIELDS, $xml_data );

curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, true );

// curl_setopt ( $ch, CURLOPT_TIMEOUT, true );

$res = curl_exec($ch);

// var_dump($res);

curl_close($ch);

return $res;

}

function GetPrePayId_Sign_ASCII_ASC_Encode($paramArray,$mykey, $isencode=false){

$paramStr = ‘’;

ksort($paramArray);

$i = 0;

foreach ($paramArray as $iKey => $value)

{

if ($iKey == ‘Signature’){

continue;

}

if ($i == 0){

$paramStr .= ‘’;

}else{

$paramStr .= ‘&’;

}

$paramStr .= $iKey . ‘=’ . ($isencode?urlencode($value):$value);

++$i;

}

$stringSignTemp=$paramStr.“&key=”.$mykey;

$sign=strtoupper(md5($stringSignTemp));

return $sign;

}