iOS上传图像到服务器，以及服务器PHP接收的几种方法

1. 将图片转换为Base64编码，POST上传。PHP将Base64解码为二进制，再写出文件。缺点：不能上传较大的图片

// iOS(Swift)func upload(image: UIImage, url: String) {    let imageData = UIImageJPEGRepresentation(image, 0.3) // 将图片转换成jpeg格式的NSData，压缩到0.3    let imageStr = imageData?.base64EncodedStringWithOptions(.Encoding64CharacterLineLength) // 将图片转换为base64字符串    let params: NSDictionary = ["file": imageStr!]    let manager = AFHTTPRequestOperationManager()    // 采用POST的方式上传，因为POST对长度没有限制    manager.POST(url, parameters: params, success: { (_: AFHTTPRequestOperation!, response: AnyObject!) in        // 成功    }) { (_: AFHTTPRequestOperation!, _: NSError!) in        // 失败    }}

2.AFNetworking上传，PHP端通过正常接收网页上传方法来接收图片

static func uploadPortrait(image: UIImage, url: String) {    let manager = AFHTTPRequestOperationManager()    // fromData: AFN封装好的http header类，可以添加请求体    manager.POST(url, parameters: [:], constructingBodyWithBlock: { (fromData: AFMultipartFormData!) in        let pngData = UIImagePNGRepresentation(image)        // name必须和后台PHP接收的参数名相同($_FILES["file"])        // fileName为图片名        fromData.appendPartWithFileData(pngData, name: "file", fileName: "image.png", mimeType: "image/png")              // let jpegData = UIImageJPEGRepresentation(image, 0.3)        // fromData.appendPartWithFileData(jpegData, name: "file", fileName: "image.jpg", mimeType: "image/jpeg")    }, success: { (operation: AFHTTPRequestOperation!, response: AnyObject!) in        // 成功    }) { (operation: AFHTTPRequestOperation!, error: NSError!) in        // 失败    }   }

 0) {        echo $_FILES["file"]["error"]; // 错误代码    } else {                   $fillname = $_FILES['file']['name']; // 得到文件全名        $dotArray = explode('.', $fillname); // 以.分割字符串，得到数组        $type = end($dotArray); // 得到最后一个元素：文件后缀        $path = "../portrait/".md5(uniqid(rand())).'.'.$type; // 产生随机唯一的名字        move_uploaded_file( // 从临时目录复制到目标目录          $_FILES["file"]["tmp_name"], // 存储在服务器的文件的临时副本的名称          $path);        echo "成功";    } } else {    echo "文件类型不正确";}?>

3.将图片封装在Http的请求报文中的请求体（body）中上传。也是AFN上传的原理

// 使用OC封装#import @interface RequestPostUploadHelper : NSObject+ (NSMutableURLRequest *)uploadImage:(NSString*)url uploadImage:(UIImage *)uploadImage params:(NSMutableDictionary *)params;@end#import "RequestPostUploadHelper.h"@implementation RequestPostUploadHelper+ (NSMutableURLRequest *)uploadImage:(NSString*)url uploadImage:(UIImage *)uploadImage params:(NSMutableDictionary *)params {    [params setObject:uploadImage forKey:@"file"];    //分界线的标识符    NSString *TWITTERFON_FORM_BOUNDARY = @"AaB03x";    //根据url初始化request    NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:url]                                                           cachePolicy:NSURLRequestReloadIgnoringLocalCacheData                                                       timeoutInterval:10];    //分界线 --AaB03x    NSString *MPboundary=[[NSString alloc]initWithFormat:@"--%@",TWITTERFON_FORM_BOUNDARY];    //结束符 AaB03x--    NSString *endMPboundary=[[NSString alloc]initWithFormat:@"%@--",MPboundary];    //要上传的图片    UIImage *image=[params objectForKey:@"file"];    //得到图片的data    NSData* data = UIImagePNGRepresentation(image);    //http body的字符串    NSMutableString *body=[[NSMutableString alloc]init];    //参数的集合的所有key的集合    NSArray *keys= [params allKeys];    //遍历keys    for(int i = 0; i < [keys count]; i++)    {        //得到当前key        NSString *key = [keys objectAtIndex:i];        //如果key不是file，说明value是字符类型，比如name：Boris        if(![key isEqualToString:@"file"])        {            //添加分界线，换行            [body appendFormat:@"%@\r\n",MPboundary];            //添加字段名称，换2行            [body appendFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n",key];            //添加字段的值            [body appendFormat:@"%@\r\n",[params objectForKey:key]];        }    }    ////添加分界线，换行    [body appendFormat:@"%@\r\n",MPboundary];    //声明file字段，文件名为image.png    [body appendFormat:@"Content-Disposition: form-data; name=\"file\"; filename=\"image.png\"\r\n"];    //声明上传文件的格式    [body appendFormat:@"Content-Type: image/png\r\n\r\n"];    //声明结束符：--AaB03x--    NSString *end=[[NSString alloc] initWithFormat:@"\r\n%@",endMPboundary];    //声明myRequestData，用来放入http body    NSMutableData *myRequestData = [NSMutableData data];    //将body字符串转化为UTF8格式的二进制    [myRequestData appendData:[body dataUsingEncoding:NSUTF8StringEncoding]];    //将image的data加入    [myRequestData appendData:data];    //加入结束符--AaB03x--    [myRequestData appendData:[end dataUsingEncoding:NSUTF8StringEncoding]];    //设置HTTPHeader中Content-Type的值    NSString *content=[[NSString alloc]initWithFormat:@"multipart/form-data; boundary=%@",TWITTERFON_FORM_BOUNDARY];    //设置HTTPHeader    [request setValue:content forHTTPHeaderField:@"Content-Type"];    //设置Content-Length    [request setValue:[NSString stringWithFormat:@"%d", [myRequestData length]] forHTTPHeaderField:@"Content-Length"];    //设置http body    [request setHTTPBody:myRequestData];    //http method    [request setHTTPMethod:@"POST"];    return request;}@end

// 使用// Swiftstatic func uploadPortrait(image: UIImage, url:String) {    // 使用    let request = RequestPostUploadHelper.uploadImage(url, uploadImage: image, params: [:])    // 异步网络请求    NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue()) { (response: NSURLResponse?, data: NSData?, error: NSError?) in        if error != nil {            // 失败        } else {            // 成功        }    }}

4.iOS图片转换为NSData，通过POST上传。PHP接收POST参数，将NSData的16进制编码转换为PHP支持的二进制，再写出文件保存

暂时没有找到办法，PHP接收到16进制编码后，使用算法转换为二进制后无法输出图片

5.二进制POST上传。PHP直接将数据保存为图片

暂时没有找到办法，iOS端使用NSData的getBytes无法转换为二进制