iOS开发 大文件下载封装

iOS开发 文件下载

功能：实现文件的断点下载，即暂停，开始

完整源码:   http://download.csdn.net/detail/u010029229/9164147

下载封装类：MyFileDownloader.h MyFileDownloader.m

////  MyFileDownloader.h//  大文件下载封装////  Created by Qianfeng on 15/10/8.//  Copyright (c) 2015年 xyz. All rights reserved.//#import <Foundation/Foundation.h>@interface MyFileDownloader : NSObject// 下载文件URL@property (nonatomic, copy) NSString *url;// 文件存储路径@property (nonatomic, copy) NSString *destPath;// 是否正在下载@property (nonatomic, readonly, getter=isDownloading) BOOL downloading;// 用来监听下载进度@property (nonatomic, copy) void(^progressHandler)(double progress);// 监听下载完毕@property (nonatomic, copy) void (^completionHandler)();// 监听下载失败@property (nonatomic, copy) void (^failureHandle)(NSError *error);// 开始下载- (void)startDownload;// 暂停下载- (void)pauseDownload;@end

////  MyFileDownloader.m//  大文件下载封装////  Created by Qianfeng on 15/10/8.//  Copyright (c) 2015年 xyz. All rights reserved.//#import "MyFileDownloader.h"@interface MyFileDownloader()<NSURLConnectionDataDelegate>@property (nonatomic, strong) NSURLConnection *conn; // 链接对象@property (nonatomic, strong) NSFileHandle *writeHandle; // 写文件句柄@property (nonatomic, assign) long long currentLength; // 当前文件总长度@property (nonatomic, assign) long long totalLength; // 文件总长度@end@implementation MyFileDownloader- (void)startDownload {    NSURL *url = [NSURL URLWithString:self.url];    // 默认就是GET请求    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];    // 设置请求头信息    NSString *value = [NSString stringWithFormat:@"bytes=%lld-", self.currentLength];    [request setValue:value forHTTPHeaderField:@"Range"];    self.conn = [NSURLConnection connectionWithRequest:request delegate:self];        _downloading = YES;}- (void)pauseDownload {    [self.conn cancel];    self.conn = nil;        _downloading = NO;}#pragma mark - NSURLConnectionDataDelegate 代理方法/** *  1. 当接受到服务器的响应(连通了服务器)就会调用 */- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{    if (self.totalLength) return;        // 1.创建一个空的文件到沙盒中    NSFileManager *mgr = [NSFileManager defaultManager];    // 刚创建完毕的大小是0字节    [mgr createFileAtPath:self.destPath contents:nil attributes:nil];        // 2.创建写数据的文件句柄    self.writeHandle = [NSFileHandle fileHandleForWritingAtPath:self.destPath];        // 3.获得完整文件的长度    self.totalLength = response.expectedContentLength;}/** *  2. 当接受到服务器的数据就会调用(可能会被调用多次, 每次调用只会传递部分数据) */- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{    // 累加长度    self.currentLength += data.length;        // 显示进度    double progress = (double)self.currentLength / self.totalLength;    if (self.progressHandler) { // 传递进度值给block        self.progressHandler(progress);    }        // 移动到文件的尾部    [self.writeHandle seekToEndOfFile];    // 从当前移动的位置(文件尾部)开始写入数据    [self.writeHandle writeData:data];}/** *  3. 当服务器的数据接受完毕后就会调用 */- (void)connectionDidFinishLoading:(NSURLConnection *)connection{    // 清空属性值    self.currentLength = 0;    self.totalLength = 0;        if (self.currentLength == self.totalLength) {        // 关闭连接(不再输入数据到文件中)        [self.writeHandle closeFile];        self.writeHandle = nil;    }        if (self.completionHandler) {        self.completionHandler();    }}/** *  请求错误(失败)的时候调用(请求超时\断网\没有网, 一般指客户端错误) */- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{    if (self.failureHandle) {        self.failureHandle(error);    }}@end

控制器源码

////  ViewController.h//  大文件下载封装////  Created by Qianfeng on 15/10/8.//  Copyright (c) 2015年 xyz. All rights reserved.//#import <UIKit/UIKit.h>@interface ViewController : UIViewController@end

////  ViewController.m//  大文件下载封装////  Created by Qianfeng on 15/10/8.//  Copyright (c) 2015年 xyz. All rights reserved.//#import "ViewController.h"#import "MyFileDownloader.h"@interface ViewController ()@property (weak, nonatomic) IBOutlet UIProgressView *progressView;@property (nonatomic, strong) MyFileDownloader *fileDownloader;- (IBAction)startDownloader:(id)sender;@property (weak, nonatomic) IBOutlet UIButton *button;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    self.progressView.progress = 0;}- (MyFileDownloader *)fileDownloader{    if (!_fileDownloader) {        _fileDownloader = [[MyFileDownloader alloc] init];                NSString *url = @"http://10.0.8.8/download/MapKit-LBS项目-FindMe.pdf";                        // 需要下载的文件远程URL        _fileDownloader.url = [url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];        // 文件保存到什么地方        NSString *caches = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];        NSString *filepath = [caches stringByAppendingPathComponent:@"abc.pdf"];        _fileDownloader.destPath = filepath;        //        typeof(10) a = 20; // int a = 20;                __weak typeof(self) vc = self;        _fileDownloader.progressHandler = ^(double progress) {            vc.progressView.progress = progress;        };                _fileDownloader.completionHandler = ^{            NSLog(@"------下载完毕");        };                _fileDownloader.failureHandle = ^(NSError *error){                    };    }    return _fileDownloader;}- (IBAction)startDownloader:(id)sender {    if (self.fileDownloader.isDownloading) { // 暂停下载        [self.fileDownloader pauseDownload];                [self.button setTitle:@"恢复" forState:UIControlStateNormal];    } else { // 开始下载        [self.fileDownloader startDownload];                [self.button setTitle:@"暂停" forState:UIControlStateNormal];    }}@end

在控制器的那两个控件就自己看着办吧。。。