PHP+HTML实现流式输出效果的示例详解_Php

效果演示

后端代码

<?php
// 关闭输出缓冲
ini_set('output_buffering', 'off');
ini_set('zlib.output_compression', false);
while (ob_get_level()) ob_end_clean(); // 清除所有缓冲层

// 设置http头（流式内容类型 + 禁用缓存）
header('content-type: text/plain; charset=utf-8');
header('cache-control: no-cache');
header('x-accel-buffering: no');

// 模拟对话回复内容
$messages = [
    "你好！我正在分析您的问题...\n",
    "已找到相关解决方案，请稍等。\n",
    "处理完成！以下是详细回答：\n"
];

// 流式输出每条消息
foreach ($messages as $msg) {
    // 逐字输出（可选）
    // $length = strlen($msg);
    $length = mb_strlen($msg);
    for ($i=0; $i<$length; $i++) {
        // echo $msg[$i];
        $char = mb_substr($msg, $i, 1, 'utf-8');
        echo $char;
        ob_flush(); // 刷新php缓冲
        flush();    // 刷新web服务器缓冲
        usleep(50000); // 50ms延迟模拟打字效果
    }
}

// 持续生成内容的例子（如从数据库/api获取）
for ($i=1; $i<=5; $i++) {
    echo "正在处理第 {$i} 项任务...\n";
    ob_flush();
    flush();
    sleep(1);
}

前端代码

<!doctype html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>智能客服系统</title>
    <style>
        body {
            font-family: arial, sans-serif;
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
            margin: 0;
            background-color: #f4f4f9;
        }
        .chat-container {
            width: 800px;
            background-color: #fff;
            border-radius: 10px;
            box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
            padding: 20px;
        }
        .messages {
            height: 500px;
            overflow-y: auto;
            border-bottom: 1px solid #ddd;
            padding-bottom: 10px;
        }
        .message {
            margin: 10px 0;
        }
        .user {
            text-align: right;
        }
        .bot {
            text-align: left;
        }
        .input-container {
            display: flex;
            margin-top: 10px;
        }
        .input-container input {
            flex: 1;
            padding: 10px;
            border: 1px solid #ddd;
            border-radius: 5px;
        }
        .input-container button {
            padding: 10px 20px;
            border: none;
            background-color: #007bff;
            color: #fff;
            border-radius: 5px;
            cursor: pointer;
        }
        .input-container button:hover {
            background-color: #0056b3;
        }
    </style>
</head>
<body>
<div class="chat-container">
    <div class="messages" id="messages" style="white-space: pre-wrap;"></div>
    <div class="input-container">
        <input type="text" id="userinput" placeholder="输入消息...">
        <button onclick="sendmessage()">发送</button>
    </div>
</div>

<script>
    function sendmessage() {
        const userinput = document.getelementbyid('userinput').value;
        if (userinput.trim() === '') return;
        document.getelementbyid('userinput').value = '';

        const messagescontainer = document.getelementbyid('messages');
        const usermessage = document.createelement('div');
        usermessage.classname = 'message user';
        usermessage.textcontent = userinput;
        messagescontainer.appendchild(usermessage);


        fetch('stream.php')
            .then(response => {
                const reader = response.body.getreader();
                const decoder = new textdecoder('utf-8');

                const botmessage = document.createelement('div');
                botmessage.classname = 'message bot';
                messagescontainer.appendchild(botmessage);

                function readchunk() {
                    return reader.read().then(({ done, value }) => {
                        if (done) return;
                        // 将二进制数据解码为文本
                        const text = decoder.decode(value);
                        // 实时追加到页面
                        botmessage.innerhtml += text;
                        messagescontainer.scrolltop = messagescontainer.scrollheight;
                        // 继续读取下一块
                        return readchunk();
                    });
                }
                return readchunk();
            })
            .catch(console.error);
    }
</script>
</body>
</html>