PHP怎么生成头像裁剪_PHP实现用户头像上传裁剪功能

<?php
// 假设这是处理上传和裁剪的PHP文件
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_FILES['avatar']) && isset($_POST['cropData'])) {
    $file = $_FILES['avatar'];
    $cropData = json_decode($_POST['cropData'], true); // 前端通常会以JSON字符串形式发送裁剪数据

    // 1. 文件上传验证
    $allowedTypes = ['image/jpeg', 'image/png', 'image/gif'];
    if (!in_array($file['type'], $allowedTypes)) {
        echo json_encode(['status' => 'error', 'message' => '不支持的图片类型。']);
        exit;
    }
    if ($file['size'] > 5 * 1024 * 1024) { // 限制5MB
        echo json_encode(['status' => 'error', 'message' => '图片大小不能超过5MB。']);
        exit;
    }

    $uploadDir = 'uploads/'; // 存储原始图片和裁剪后图片的目录
    if (!is_dir($uploadDir)) {
        mkdir($uploadDir, 0777, true);
    }

    $originalFileName = $file['name'];
    $fileExtension = pathinfo($originalFileName, PATHINFO_EXTENSION);
    $uniqueFileName = uniqid() . '_' . md5(microtime()) . '.' . $fileExtension;
    $targetPath = $uploadDir . $uniqueFileName;

    if (!move_uploaded_file($file['tmp_name'], $targetPath)) {
        echo json_encode(['status' => 'error', 'message' => '文件上传失败。']);
        exit;
    }

    // 2. 图片裁剪处理
    $srcImage = null;
    switch ($file['type']) {
        case 'image/jpeg':
            $srcImage = imagecreatefromjpeg($targetPath);
            break;
        case 'image/png':
            $srcImage = imagecreatefrompng($targetPath);
            break;
        case 'image/gif':
            $srcImage = imagecreatefromgif($targetPath);
            break;
    }

    if (!$srcImage) {
        unlink($targetPath); // 删除原始上传文件
        echo json_encode(['status' => 'error', 'message' => '无法加载图片。']);
        exit;
    }

    $src_x = intval($cropData['x']);
    $src_y = intval($cropData['y']);
    $src_w = intval($cropData['width']);
    $src_h = intval($cropData['height']);

    // 假设我们希望最终头像尺寸是150x150
    $dest_w = 150;
    $dest_h = 150;

    $destImage = imagecreatetruecolor($dest_w, $dest_h);

    // 对于PNG图片，需要保留透明度
    if ($file['type'] === 'image/png') {
        imagealphablending($destImage, false);
        imagesavealpha($destImage, true);
        $transparent = imagecolorallocatealpha($destImage, 255, 255, 255, 127);
        imagefilledrectangle($destImage, 0, 0, $dest_w, $dest_h, $transparent);
    }

    // 执行裁剪和缩放
    if (!imagecopyresampled($destImage, $srcImage, 0, 0, $src_x, $src_y, $dest_w, $dest_h, $src_w, $src_h)) {
        imagedestroy($srcImage);
        imagedestroy($destImage);
        unlink($targetPath);
        echo json_encode(['status' => 'error', 'message' => '图片裁剪失败。']);
        exit;
    }

    // 3. 保存裁剪后的图片
    $croppedFileName = 'avatar_' . uniqid() . '.' . $fileExtension; // 裁剪后图片的新文件名
    $croppedPath = $uploadDir . $croppedFileName;

    switch ($file['type']) {
        case 'image/jpeg':
            imagejpeg($destImage, $croppedPath, 90); // 质量90
            break;
        case 'image/png':
            imagepng($destImage, $croppedPath);
            break;
        case 'image/gif':
            imagegif($destImage, $croppedPath);
            break;
    }

    // 4. 清理资源
    imagedestroy($srcImage);
    imagedestroy($destImage);
    unlink($targetPath); // 删除原始上传文件

    // 返回成功信息和裁剪后图片的URL
    echo json_encode(['status' => 'success', 'message' => '头像裁剪成功！', 'avatarUrl' => '/' . $croppedPath]);

} else {
    echo json_encode(['status' => 'error', 'message' => '无效的请求。']);
}
?>

// 假设已经裁剪出150x150的$destImage
// 生成其他尺寸
$sizes = [
    'small' => 30,
    'medium' => 50,
    'large' => 100
];

foreach ($sizes as $key => $size) {
    $resizedImage = imagecreatetruecolor($size, $size);
    imagecopyresampled($resizedImage, $destImage, 0, 0, 0, 0, $size, $size, imagesx($destImage), imagesy($destImage));
    $resizedPath = $uploadDir . 'avatar_' . $key . '_' . uniqid() . '.' . $fileExtension;
    imagejpeg($resizedImage, $resizedPath, 90);
    imagedestroy($resizedImage);
    // 这里可以将$resizedPath保存到数据库或返回给前端
}