Question

我试着打电话给我的变种＆＃34; o＆＃34;或＆＃34;＆＃34;或null或false或＆＃34; undefined＆＃34;但它不起作用。我的问题是，我与一个代码聊天，说要在2秒内自行重新加载页面，但如果有人在textarea中写，那么它会删除文本。我需要一个代码，说每2秒重新加载一次页面，但如果有人在textarea中写入，那么它应该在发送文本后重新加载。你可以看到代码，如果你想尝试代码只需复制它。但首先你必须在你的sql中创建一个名为＆＃34; my_db＆＃34;的数据库。然后运行该页面。

<?php
    $hostname_db = "localhost";
    $database_db = "my_db";
    $username_db = "root";
    $password_db = "";
    $db = mysql_pconnect($hostname_db, $username_db, $password_db) or trigger_error(mysql_error(),E_USER_ERROR); 
    ?>
    <?php
    if (!function_exists("GetSQLValueString")) {
    function GetSQLValueString($theValue, $theType, $theDefinedValue = "", $theNotDefinedValue = "") 
    {
      if (PHP_VERSION < 6) {
        $theValue = get_magic_quotes_gpc() ? stripslashes($theValue) : $theValue;
      }

      $theValue = function_exists("mysql_real_escape_string") ? mysql_real_escape_string($theValue) : mysql_escape_string($theValue);

      switch ($theType) {
        case "text":
          $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
          break;    
        case "long":
        case "int":
          $theValue = ($theValue != "") ? intval($theValue) : "NULL";
          break;
        case "double":
          $theValue = ($theValue != "") ? doubleval($theValue) : "NULL";
          break;
        case "date":
          $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
          break;
        case "defined":
          $theValue = ($theValue != "") ? $theDefinedValue : $theNotDefinedValue;
          break;
      }
      return $theValue;
    }
    }

    //select db and create table to chat


    $conn = new PDO("mysql:host=$hostname_db", $username_db, $password_db);
    $sql = "use my_db";
    $conn->exec($sql);
    $sql = "CREATE TABLE IF NOT EXISTS `chatroom`(
    `idmassage` int(11) NOT NULL AUTO_INCREMENT,
    `massage` text NULL,
    `user` varchar(50) NOT NULL,    
    `date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (`idmassage`)
    ) ENGINE=InnoDB  DEFAULT CHARSET=hebrew ";
    $conn->exec($sql);



    //select chatroom from dataase

    mysql_select_db($database_db, $db);
    $query_chat = "SELECT massage, `user`, `date` FROM chatroom ORDER BY idmassage ASC";
    $chat = mysql_query($query_chat, $db) or die(mysql_error());
    $row_chat = mysql_fetch_assoc($chat);
    $totalRows_chat = mysql_num_rows($chat);

    //inser new data
    $editFormAction = $_SERVER['PHP_SELF'];
    if (isset($_SERVER['QUERY_STRING'])) {
      $editFormAction .= "?" . htmlentities($_SERVER['QUERY_STRING']);
    }

    if ((isset($_POST["MM_insert"])) && ($_POST["MM_insert"] == "chat")) {
      $insertSQL = sprintf("INSERT INTO chatroom (massage) VALUES (%s)",
                           GetSQLValueString($_POST['massage'], "text"));

      mysql_select_db($database_db, $db);
      $Result1 = mysql_query($insertSQL, $db) or die(mysql_error());

      $insertGoTo = "chatTest.php";
      if (isset($_SERVER['QUERY_STRING'])) {
        $insertGoTo .= (strpos($insertGoTo, '?')) ? "&" : "?";
        $insertGoTo .= $_SERVER['QUERY_STRING'];
      }
      header(sprintf("Location: %s", $insertGoTo));
    }
    //mysql_close($db);
    ?>
    <!doctype html>
    <html>
    <head>
    <meta charset="utf-8">
    <title>Untitled Document</title>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.0.0/jquery.min.js"></script>




    <style type="text/css">
    body {
        margin: 0;
        background-color: #D4CACB;
    }
    .chat {
        width: 60%;
        background-color: #878787;
        position: fixed;
    }
    .chat .massagechat {
        overflow-y: scroll;
        width: 100%;
        height: 400px;
    }
    #chat #massagechat #refresh {
        width: 100%;
        background-color: #FFFFFF;
        margin-top: 14px;
    }
    body p {
        position: fixed;
        float: right;
        margin-top: 482px;
        margin-left: 94px;
    }
    </style>
    </head>

    <body>
    <div id="chat" class="chat">
        <div id="massagechat" class="massagechat">
            <?php do { ?>
            <div id="refresh">
               <p1><?php echo $row_chat['user']." ".$row_chat['date']."</br>"; ?></p1>
               <p2><?php echo $row_chat['massage']; ?></p2>
            </div>
            <?php } while ($row_chat = mysql_fetch_assoc($chat)); ?>

        </div>

        <div class="form">
            <form method="POST" action="<?php echo $editFormAction; ?>" name="chat">
                <textarea name="massage"  id="input" placeholder=" "></textarea>
                    <input id="submit" type="submit">
                         <input type="hidden" name="MM_insert" value="chat">
            </form>
        </div>
    </div>
    <p>dddd</p>
    <p><?php echo $row_chat; ?></p>

    </body>
    </html>
    <?php
    mysql_free_result($chat);
    ?>
    <script>
    $( "div.massagechat" ).scrollTop( 999999*999999);
    </script>
    <script>

    ////////////
    $('textarea').on('keyup',function(){

    var input = $(this);

        if(input.val().length == ""){

    var cacheData;
    var data = $("chat").html();
    var auto_refresh = setInterval(
    function ()
    {
        $.ajax({
            url: 'chatTest.php',
            type: 'POST',
            data: data,
            dataType: 'html',
            success: function(data) {
                if (data !== cacheData){
                    //data has changed (or it's the first call), save new cache data and update div
                    cacheData = data;
                    $("#chat").html(data);
                }           
            }
        })
    }, 2000);};})// check every 30000 milliseconds
    </script>

Answer 1

setInterval函数不应位于文本区域的 keyup 事件下。您可以将它放在文档就绪处理程序下。

同样在setInterval函数内部检查文本区域值，仅在它不为空时发送请求。

像这样，

$(document).ready(function(e){
      var auto_refresh = setInterval(
    function ()
    {
        if($('textarea').val().trim()!='') {
                $.ajax({
                    url: 'chatTest.php',
                    type: 'POST',
                    data: data,
                    dataType: 'html',
                    success: function(data) {
                        if (data !== cacheData){
                            //data has changed (or it's the first call), save new cache data and update div
                            cacheData = data;
                            $("#chat").html(data);
                        }           
                    }
                });
        }
    }, 2000);
});

如果我的变量不存在，我如何调用函数？

1 个答案: