phpcms调用getJSON无法返回json数据的解决方法

/**

* 检查hash值，验证用户数据安全性

*/

final private function check_hash() {

if(preg_match('/^public_/', ROUTE_A) || ROUTE_M =='admin' && ROUTE_C =='index' || in_array(ROUTE_A, array('login'))) {

return true;

}

if(isset($_GET['pc_hash']) && $_SESSION['pc_hash'] != '' && ($_SESSION['pc_hash'] == $_GET['pc_hash'])) {

return true;

} elseif(isset($_POST['pc_hash']) && $_SESSION['pc_hash'] != '' && ($_SESSION['pc_hash'] == $_POST['pc_hash'])) {

return true;

} else {

showmessage(L('hash_check_false'),HTTP_REFERER);

}

}

public function public_mobile_getjson_ids() {//publc是后来加上去的

$modelid = intval($_GET['modelid']);

$id = intval($_GET['id']);

$this->db->set_model($modelid);

$tablename = $this->db->table_name;

$this->db->table_name = $tablename.'_data';

$r = $this->db->get_one(array('id'=>$id),'mobile_type');

if($r['mobile_type']) {

$relation = str_replace('|', ',', $r['mobile_type']);

$relation = trim($relation,',');

$where = "id IN($relation)";

$infos = array();

$this->mobile_db = pc_base::load_model ( 'mobile_type_model' );

$datas = $this->mobile_db->select($where,'id,type_name');

//$this->db->table_name = $tablename;

//$datas = $this->db->select($where,'id,title');

foreach($datas as $_v) {

$_v['sid'] = 'v'.$_v['id'];

if(strtolower(CHARSET)=='gbk') $_v['type_name'] = iconv('gbk', 'utf-8', $_v['type_name']);

$infos[] = $_v;

}

echo json_encode($infos);

}

}

//显示添加机型

function show_mobiletype(modelid,id) {

$.getJSON("?m=content&c=content&a=public_mobile_getjson_ids&modelid="+modelid+"&id="+id, function(json){

var newrelation_ids = '';

if(json==null) {

alert('没有添加相关文章');

return false;

}

$.each(json, function(i, n){

newrelation_ids += "<li id='"+n.sid+"'>·<span>"+n.type_name+"</span><a href='javascript:;' class='close' onclick="remove_relation('"+n.sid+"',"+n.id+")"></a></li>";

});

$('#mobile_type_text').html(newrelation_ids);

});

}