無法使用javascript從php文件發送和接收信息

Question

我發送一些信息給運行查詢的php文件，但我也想同時從該php文件中檢索一些信息。 PHP文件執行得很好，但我無法獲得json_encoded對象。

JavaScript函數發送一個字符串和數字的PHP文件：一個使用字符串和數量，並更新表

<?php 
    include("config.php"); 
    session_start(); 

    $status = $_POST["Status"]; 
    $num = $_POST["TicketNum"]; 
    $newStatus = " "; 
    if(strcmp($status, "Open") == 0){ 
     $newStatus = "Closed"; 
    } 
    elseif(strcmp($status, "Closed") == 0){ 
      $newStatus = "Open"; 
    } 

    $sql = "UPDATE tickets SET Status = \"$newStatus\" where TicketNum = $num "; 
    $r = $conn ->query($sql) or trigger_error($conn->error."[$sql]"); 

    $sql = "SELECT * FROM tickets where TicketNum = $num"; 
    $result = $conn->query($sql); 
    while($row = $result->fetch_assoc()){ 
     $data[] = $row; 
    } 

    echo json_encode($data); 

?> 

我怎樣才能找回json_encoded

function open_close(){ 
    var status = encodeURIComponent(SelectedTicket["Status"]); 
    var ticketNum = encodeURIComponent(SelectedTicket["TicketNum"]); 
    var info = "Status="+status+"&TicketNum="+ticketNum; 
    var http3 = createAjaxRequestObject(); 

    if (http3.readyState == 4) { 
     if (http3.status == 200){ 
      alert("Ticket Updated!"); //This never gets hit      
      getUpdatedTicket(JSON.parse(http3.responseText)); 
     } 
    } 

    http3.open("POST", "openClose.php", true); 
    http3.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); 
    http3.send(info); 
} 

PHP文件對象在同一個JavaScript函數中？

Answer 1

你需要一個readyState偵聽器時請求做是爲了知道，然後從responseText

function open_close() { 
    var status = encodeURIComponent(SelectedTicket["Status"]); 
    var ticketNum = encodeURIComponent(SelectedTicket["TicketNum"]); 
    var info = "Status=" + status + "&TicketNum=" + ticketNum; 
    var http3 = createAjaxRequestObject(); 

    http3.onreadystatechange = function() { 
     if (http3.readyState == 4) { 
      if (http3.status == 200) { 
       console.log(http3.responseText); // <- it's there 
      } 
     }  
    } 

    http3.open("POST", "openClose.php", true); 
    http3.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); 
    http3.send(info); 
}