iOS上传文件

参加工作也有一段时间了,自己觉得是时候对自己工作的经验做一点总结了,也是为了以后闲时能看看自己的成长吧。所以,是时候写点什么了。

通过Http上传文件

因为iOS不能通过html表单来进行post上传,所以iOS想要完成上传功能就要自己实现http请求
http post请求的格式是这样的

Content-type:multipart/formdata, boundary=boundary

--boundary
Content-disposition: form-data; name="name"

mike

--boundary
Content-disposition: form-data; name: "pic", filename: "myPic.jpg"
Content-type: image/jpg

<myPic.jpg>

--boundary--

这就是我们上传时需要配置的http
boundary规定的是什么,后面就要一样。boundary 是分割各个参数的分隔符。 注意:boundary结尾时,是--boundary--,代表请求体结束。multipart/formdata 上传的请求头必须包含一个特殊的信息:Content-type 其值也必须是multipart/formdata 如果是一个文件则需要文件信息filename:"myPic.jpg"与文件内容类型Content-type:image/jpg,<myPic.jpg> 则是我们想要上传的图片或者文件。
一定要严格按照规则,否则不会成功

下面是iOS实现代码:

    NSDictionary *param = @{@"name":@"mike"};
    NSString *TWITTERFON_FORM_BOUNDARY = @"12344321";
    NSMutableURLRequest *mulrequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http"] cachePolicy:(NSURLRequestReloadIgnoringLocalCacheData) timeoutInterval:10];
    NSString *boundary = [NSString stringWithFormat:@"--%@",TWITTERFON_FORM_BOUNDARY];
    NSString *endBoundary = [NSString stringWithFormat:@"--%@--",TWITTERFON_FORM_BOUNDARY];
    UIImage *image = [UIImage imageNamed:@"pic"];
    NSData *imageData = UIImageJPEGRepresentation(image, 0.3);
    NSMutableString *body = [NSMutableString string];
    NSArray *keys = [param allKeys];
    for (NSString *key in keys) {
        [body appendFormat:@"%@\r\n",boundary];
        [body appendFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n",key];
        [body appendFormat:@"%@\r\n",[dic objectForKey:key]];
    }
    [body appendFormat:@"%@\r\n",boundary];
    [body appendFormat:@"Content-Disposition:form-data; name=\"pic\"; filename=\"myPic.jpg\"\r\n"];
    [body appendFormat:@"Cotent-Type: image/png"];
    NSMutableData *requestData = [NSMutableData data];
    [requestData appendData:[body dataUsingEncoding:NSUTF8StringEncoding]];
    [requestData appendData:imageData];
    [requestData appendData:[[NSString stringWithFormat:@"\r\n%@",endBoundary] dataUsingEncoding:NSUTF8StringEncoding]];
    NSString *content = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",TWITTERFON_FORM_BOUNDARY];
    [mulrequest setValue:content forHTTPHeaderField:@"Content-Type"];
    [mulrequest setValue:[NSString stringWithFormat:@"%lu", [requestData length]] forHTTPHeaderField:@"Content-Length"];
    [mulrequest setHTTPBody:requestData];
    [mulrequest setHTTPMethod:@"POST"];
    NSURLSessionConfiguration *sessionCon = [NSURLSessionConfiguration defaultSessionConfiguration];
    NSURLSession *session = [NSURLSession sessionWithConfiguration:sessionCon];
    NSURLSessionDataTask *task = [session dataTaskWithRequest:mulrequest completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        NSLog(@"complite");
    }];
    [task resume];

AFN上传

通常,我们并不需要配置如此麻烦的东西.因为总有一些大神来帮助我们.我们熟悉的AFN框架就很好的解决这些麻烦的配置问题,这一章主要来看看如何通过AFN来实现文件上传.在下一章,会对AFN的主要源码进行分析,敬请期待
AFN代码如下

AFHTTPSessionManager *sharedManager1 = [[AFHTTPSessionManager alloc]init];
sharedManager1.requestSerializer = [AFHTTPRequestSerializer serializer];
sharedManager1.responseSerializer.acceptableContentTypes = [NSSet setWithObjects:@"application/json", @"text/json", @"text/javascript", @"text/html", @"text/plain",nil];
sharedManager1.requestSerializer.timeoutInterval =20;
[sharedManager1.requestSerializer setValue:@"application/json" forHTTPHeaderField:@"Accept"];
[sharedManager1.requestSerializer setValue:@"text/html; charset=utf-8" forHTTPHeaderField:@"Content-Type"];
    NSDictionary *dic = @{@"param.token":_token};
[sharedManager1 POST:kUploadFile parameters:dic constructingBodyWithBlock:^(id<AFMultipartFormData>  _Nonnull formData) {
        for (int i = 0; i < fileUpload.count; i ++) {
                NSData *data = UIImageJPEGRepresentation(fileUpload[i], 0.3);
                NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
                // 设置时间格式
                formatter.dateFormat = @"yyyyMMddHHmmss";
                NSString *str = [formatter stringFromDate:[NSDate date]];
                NSString *fileName = [NSString stringWithFormat:@"%@-%@.jpeg", str,[NSString stringWithFormat:@"%d",i]];
                [formData appendPartWithFileData:data name:@"fileUpload" fileName:fileName mimeType:@"image/jpeg"];     
        }
    } success:^(NSURLSessionDataTask * _Nonnull task, id  _Nonnull responseObject) {
        success(task,responseObject);
    } failure:^(NSURLSessionDataTask * _Nonnull task, NSError * _Nonnull error) {
        fail(task,error);
    }];

我们在上传图片是需要对图片进行压缩编码,通常是使用UIImageJPEGRepresentation(,) 方法 float数一般是0.3~0.5

其他上传方式

当然,系统的NSURLSession 类提供了专门上传的方法

- (NSURLSessionUploadTask *)uploadTaskWithStreamedRequest:(NSURLRequest *)request;

AFN的上传就是基于这个方法完成的,有兴趣的可以百度了解一下,下一节我会对AFN的主要源码进行分析