聊天php源代码（社交php源码）

很抱歉，我不能提供具体的源代码，但我可以给你一个简单的聊天系统的示例代码，供你参考：

<?php
session_start();

// 连接数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

$conn = new mysqli($servername, $username, $password, $dbname);

if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 处理用户登录
if(isset($_POST['login'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];

    // 验证用户名和密码
    $sql = "SELECT * FROM users WHERE username = '$username' AND password = '$password'";
    $result = $conn->query($sql);

    if ($result->num_rows == 1) {
        $_SESSION['username'] = $username;
        header("Location: chat.php");
    } else {
        echo "用户名或密码错误";
    }
}

// 处理用户注册
if(isset($_POST['register'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];

    // 检查用户名是否已存在
    $sql = "SELECT * FROM users WHERE username = '$username'";
    $result = $conn->query($sql);

    if ($result->num_rows > 0) {
        echo "该用户名已存在";
    } else {
        // 插入新用户到数据库
        $sql = "INSERT INTO users (username, password) VALUES ('$username', '$password')";
        if ($conn->query($sql) === TRUE) {
            echo "注册成功";
        } else {
            echo "注册失败: " . $conn->error;
        }
    }
}

// 处理用户发送消息
if(isset($_POST['send'])) {
    $message = $_POST['message'];
    $username = $_SESSION['username'];

    // 插入消息到数据库
    $sql = "INSERT INTO messages (username, message) VALUES ('$username', '$message')";
    if ($conn->query($sql) === TRUE) {
        echo "消息发送成功";
    } else {
        echo "消息发送失败: " . $conn->error;
    }
}

// 获取所有消息
$sql = "SELECT * FROM messages";
$result = $conn->query($sql);

?>

<!-- 登录页面 -->
<?php if(!isset($_SESSION['username'])) { ?>
    <h2>登录</h2>
    <form method="POST" action="">
        <input type="text" name="username" placeholder="用户名" required><br>
        <input type="password" name="password" placeholder="密码" required><br>
        <input type="submit" name="login" value="登录">
    </form>

    <h2>注册</h2>
    <form method="POST" action="">
        <input type="text" name="username" placeholder="用户名" required><br>
        <input type="password" name="password" placeholder="密码" required><br>
        <input type="submit" name="register" value="注册">
    </form>
<?php } ?>

<!-- 聊天页面 -->
<?php if(isset($_SESSION['username'])) { ?>
    <h2>欢迎, <?php echo $_SESSION['username']; ?></h2>
    <form method="POST" action="">
        <input type="text" name="message" placeholder="输入消息" required><br>
        <input type="submit" name="send" value="发送">
    </form>

    <h2>消息列表</h2>
    <?php
    if ($result->num_rows > 0) {
        while($row = $result->fetch_assoc()) {
            echo "<p><strong>" . $row["username"]. ": </strong>" . $row["message"]. "</p>";
        }
    }
    ?>
<?php } ?>

<?php
// 关闭数据库连接
$conn->close();
?>

这只是一个简单的聊天系统的示例代码，你可以根据自己的需求进行修改和扩展。请注意，这个示例代码只包含了基本的功能，实际的社交网络系统会更加复杂。