一：header['content-type'] 為 application/json 的資料

    wx.request({
      url: apiUrl,  //替換成自己的伺服器地址
      data: {
        aaa:1111
      },
      method:'POST|GET',
      header: { 'content-type': 'application/json'},
      success:function(res){
        callback(res);
      },
      fail:function(){
        console.log('介面呼叫失敗')
      }
    })
 

$a=file_get_contents('php://input');
echo $a;    //{aaa:1111}

echo json_encode($_GET);    //{aaa:1111}

二：header['content-type'] 為 application/x-www-form-urlencoded 的資料

    var param={aa:11,bb:22}
    var str = []
    for (var p in param) {
      str.push(encodeURIComponent(p) + "=" + encodeURIComponent(param[p]))
    }
    str=str.join("&")
    console.log(str)    //aa=11&bb=22
    var apiUrl ='http://127.0.0.1'
    wx.request({
      url: apiUrl,  //替換成自己的伺服器地址
      data: str|param,    //POST用str，GET用param
      method:'POST|GET',
      header: { 'content-type': 'application/x-www-form-urlencoded'},
      success:function(res){
        callback(res);
      },
      fail:function(){
        console.log('介面呼叫失敗')
      }
    })
 

echo json_encode($_POST);           //{aa: "11", bb: "22"}

echo json_encode($_GET);           //{aa: "11", bb: "22"}