iOS Swift 5 Alamofire 与 PHP 实现健壮的图片上传教程

import Alamofire
import UIKit // 确保导入 UIKit 以使用 UIImage

// 假设 imageData 是从 UIImage 转换而来的 Data
// 例如：let imageData = UIImage(named: "yourImage")?.pngData()
// 确保 imageData 不为空

func uploadImage(imageData: Data, to url: URL) {
    AF.upload(
        multipartFormData: { multipartFormData in
            // 1. 添加图片数据
            // withName: "image" 必须与 PHP 后端接收的字段名完全一致
            multipartFormData.append(imageData, withName: "image", fileName: "test.png", mimeType: "image/png")

            // 2. 如果需要，可以添加其他文本参数
            // multipartFormData.append("someValue".data(using: .utf8)!, withName: "key")
        },
        to: url,
        method: .post, // 明确指定 HTTP 方法为 POST
        headers: nil // 可选：如果需要自定义请求头
    )
    .uploadProgress { progress in
        // 实时监听上传进度
        print("Upload Progress: \(progress.fractionCompleted)")
    }
    .responseJSON { response in
        // 处理服务器响应
        switch response.result {
        case .success(let json):
            print("Upload Success: \(json)")
        case .failure(let error):
            print("Upload Failed: \(error)")
            // 详细错误信息
            if let data = response.data, let errorString = String(data: data, encoding: .utf8) {
                print("Server Error Response: \(errorString)")
            }
        }
    }
}

// 示例调用 (假设您有一个 UIImage 对象)
// if let image = UIImage(named: "yourLocalImage") {
//     if let imageData = image.pngData() {
//         let serverURL = URL(string: "http://your-server-ip/upload.php")!
//         uploadImage(imageData: imageData, to: serverURL)
//     }
// }

<?php

header('Content-Type: application/json'); // 确保返回 JSON 格式

$response = array();

// 检查是否存在名为 "image" 的上传文件
// "image" 必须与 Swift 客户端 multipartFormData.append(imageData, withName: "image", ...) 中的 name 一致
if (empty($_FILES["image"])) {
    $response["error"] = "nodata"; // 没有接收到文件数据
} else {
    // 检查上传过程中是否有错误
    if ($_FILES["image"]["error"] !== UPLOAD_ERR_OK) {
        $response["status"] = "Failure";
        $response["error_code"] = $_FILES["image"]["error"]; // PHP 错误码
        $response["error_message"] = "Upload error: " . get_upload_error_message($_FILES["image"]["error"]);
        $response["name"] = $_FILES["image"]["name"];
        $response["type"] = $_FILES["image"]["type"];
        $response["size"] = $_FILES["image"]["size"];
    } else {
        // 定义文件保存路径
        // 注意：D:/emailback/images/ 路径在服务器上必须存在且可写
        $uploadDir = "D:/emailback/images/"; // 根据您的服务器环境修改
        $filename = basename($_FILES["image"]["name"]); // 获取原始文件名
        $targetPath = $uploadDir . $filename;

        // 确保上传目录存在且可写
        if (!is_dir($uploadDir)) {
            mkdir($uploadDir, 0777, true); // 尝试创建目录
        }

        if (move_uploaded_file($_FILES["image"]["tmp_name"], $targetPath)) {
            $response["status"] = "success";
            $response["filename"] = $filename; // 正确获取上传文件的名称
            $response["filepath"] = $targetPath;
        } else {
            $response["status"] = "Failure";
            $response["error"] = "Failed to move uploaded file.";
            $response["name"] = $_FILES["image"]["name"];
            $response["path"] = $targetPath;
            $response["type"] = $_FILES["image"]["type"];
            $response["size"] = $_FILES["image"]["size"];
            // 进一步检查 move_uploaded_file 失败的原因，例如权限问题
            if (!is_writable($uploadDir)) {
                $response["error_detail"] = "Upload directory is not writable.";
            }
        }
    }
}

echo json_encode($response);

// 辅助函数：将 PHP 上传错误码转换为可读信息
function get_upload_error_message($code) {
    switch ($code) {
        case UPLOAD_ERR_INI_SIZE:
            return "The uploaded file exceeds the upload_max_filesize directive in php.ini";
        case UPLOAD_ERR_FORM_SIZE:
            return "The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form";
        case UPLOAD_ERR_PARTIAL:
            return "The uploaded file was only partially uploaded";
        case UPLOAD_ERR_NO_FILE:
            return "No file was uploaded";
        case UPLOAD_ERR_NO_TMP_DIR:
            return "Missing a temporary folder";
        case UPLOAD_ERR_CANT_WRITE:
            return "Failed to write file to disk";
        case UPLOAD_ERR_EXTENSION:
            return "A PHP extension stopped the file upload";
        default:
            return "Unknown upload error";
    }
}

?>