iOS开发-文件上传原理

• 文件上传

1. 编写文件上传类UploadFile.h

   //
   //  UploadFile.h
   //  02.Post上传
   //
   //  Created by wyh on 15-1-29.
   //  Copyright (c) 2015年 itcast. All rights reserved.
   //
   
   #import <Foundation/Foundation.h>
   
   @interface UploadFile : NSObject
   
   - (void)uploadFileWithURL:(NSURL *)url data:(NSData *)data;
   
   @end

2. 编写文件上传类UploadFile.m

   //
   //  UploadFile.m
   //  02.Post上传
   //
   //  Created by why on 15-1-29.
   //  Copyright (c) 2015年 itcast. All rights reserved.
   //
   
   #import "UploadFile.h"
   
   @implementation UploadFile
   // 拼接字符串
   static NSString *boundaryStr = @"--";   // 分隔字符串
   static NSString *randomIDStr;           // 本次上传标示字符串
   static NSString *uploadID;              // 上传(php)脚本中，接收文件字段
   
   - (instancetype)init
   {
       self = [super init];
       if (self) {
           randomIDStr = @"itcast";
           uploadID = @"uploadFile";
       }
       return self;
   }
   
   #pragma mark - 私有方法
   - (NSString *)topStringWithMimeType:(NSString *)mimeType uploadFile:(NSString *)uploadFile
   {
       NSMutableString *strM = [NSMutableString string];
       
       [strM appendFormat:@"%@%@
   ", boundaryStr, randomIDStr];
       [strM appendFormat:@"Content-Disposition: form-data; name="%@"; filename="%@"
   ", uploadID, uploadFile];
       [strM appendFormat:@"Content-Type: %@
   
   ", mimeType];
       
       NSLog(@"%@", strM);
       return [strM copy];
   }
   
   - (NSString *)bottomString
   {
       NSMutableString *strM = [NSMutableString string];
       
       [strM appendFormat:@"%@%@
   ", boundaryStr, randomIDStr];
       [strM appendString:@"Content-Disposition: form-data; name="submit"
   
   "];
       [strM appendString:@"Submit
   "];
       [strM appendFormat:@"%@%@--
   ", boundaryStr, randomIDStr];
       
       NSLog(@"%@", strM);
       return [strM copy];
   }
   
   #pragma mark - 上传文件
   - (void)uploadFileWithURL:(NSURL *)url data:(NSData *)data
   {
       // 1> 数据体
       NSString *topStr = [self topStringWithMimeType:@"image/png" uploadFile:@"头像1.png"];
       NSString *bottomStr = [self bottomString];
       
       NSMutableData *dataM = [NSMutableData data];
       [dataM appendData:[topStr dataUsingEncoding:NSUTF8StringEncoding]];
       [dataM appendData:data];
       [dataM appendData:[bottomStr dataUsingEncoding:NSUTF8StringEncoding]];
       
       // 1. Request
       NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:0 timeoutInterval:2.0f];
       
       // dataM出了作用域就会被释放,因此不用copy
       request.HTTPBody = dataM;
       
       // 2> 设置Request的头属性
       request.HTTPMethod = @"POST";
       
       // 3> 设置Content-Length
       NSString *strLength = [NSString stringWithFormat:@"%ld", (long)dataM.length];
       [request setValue:strLength forHTTPHeaderField:@"Content-Length"];
       
       // 4> 设置Content-Type
       NSString *strContentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", randomIDStr];
       [request setValue:strContentType forHTTPHeaderField:@"Content-Type"];
       
       // 3> 连接服务器发送请求
       [NSURLConnection sendAsynchronousRequest:request queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
           
           NSString *result = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
           NSLog(@"%@", result);
       }];
   }
   
   
   
   @end

3. 控制器调用

   //
   //  MJViewController.m
   //  02.Post上传
   //
   //  Created by wyh on 15-1-29.
   //  Copyright (c) 2015年 itcast. All rights reserved.
   //
   
   #import "ViewController.h"
   #import "UploadFile.h"
   
   @interface ViewController ()
   
   @end
   
   @implementation ViewController
   
   - (void)viewDidLoad
   {
       [super viewDidLoad];
   
       UploadFile *upload = [[UploadFile alloc] init];
       
       NSString *urlString = @"http://localhost/upload.php";
       
       NSString *path = [[NSBundle mainBundle] pathForResource:@"头像1.png" ofType:nil];
       NSData *data = [NSData dataWithContentsOfFile:path];
       
       [upload uploadFileWithURL:[NSURL URLWithString:urlString] data:data];
   }
   
   @end