xutils3 下载文件进度的进度和下载需要的时间有什么关系

来源：蜘蛛抓取(WebSpider) 时间：2015-06-21 01:09 标签： java 下载文件 进度条
迅雷怎么移动下载的文件而不影响下载的进度_百度知道downloadFile 下载文件界面，带进度条的，显示当前 ， 完成提示用户 ！ StatusBar 状态条 238万源代码下载-
&文件名称: downloadFile
& & & & &&]
&&所属分类:
&&开发工具: Java
&&文件大小: 65 KB
&&上传时间:
&&下载次数: 7
&&提 供 者:
&详细说明：下载文件界面，带进度条的，显示当前下载进度，下载完成提示用户下载完成！-Download interface, with a progress bar displays the current progress of the download, download the complete prompts the user to download is complete!
文件列表(点击判断是否您需要的文件，如果是垃圾请在下面评价投诉):
&&downloadFile\.classpath&&............\.project&&............\.settings\org.eclipse.core.resources.prefs&&............\AndroidManifest.xml&&............\bin\classes\com\spring\sky\download\FileUtil.class&&............\...\.......\...\......\...\........\IndexActivity$1.class&&............\...\.......\...\......\...\........\IndexActivity$2.class&&............\...\.......\...\......\...\........\IndexActivity.class&&............\...\.......\...\......\...\........\R$attr.class&&............\...\.......\...\......\...\........\R$drawable.class&&............\...\.......\...\......\...\........\R$id.class&&............\...\.......\...\......\...\........\R$layout.class&&............\...\.......\...\......\...\........\R$string.class&&............\...\.......\...\......\...\........\R.class&&............\...\classes.dex&&............\...\downloadFile.apk&&............\...\res\drawable-hdpi\ic_launcher.png&&............\...\...\.........ldpi\ic_launcher.png&&............\...\...\.........mdpi\ic_launcher.png&&............\...\resources.ap_&&............\gen\com\spring\sky\download\R.java&&............\proguard.cfg&&............\project.properties&&............\res\drawable-hdpi\ic_launcher.png&&............\...\.........ldpi\ic_launcher.png&&............\...\.........mdpi\ic_launcher.png&&............\...\layout\main.xml&&............\...\values\strings.xml&&............\src\com\spring\sky\download\FileUtil.java&&............\...\...\......\...\........\IndexActivity.java&&............\bin\classes\com\spring\sky\download&&............\...\.......\...\......\sky&&............\gen\com\spring\sky\download&&............\src\com\spring\sky\download&&............\bin\classes\com\spring&&............\gen\com\spring\sky&&............\src\com\spring\sky&&............\bin\classes\com&&............\...\res\drawable-hdpi&&............\...\...\drawable-ldpi&&............\...\...\drawable-mdpi&&............\gen\com\spring&&............\src\com\spring&&............\bin\classes&&............\...\res&&............\gen\com&&............\res\drawable-hdpi&&............\...\drawable-ldpi&&............\...\drawable-mdpi&&............\...\layout&&............\...\values&&............\src\com&&............\.settings&&............\assets&&............\bin&&............\gen&&............\res&&............\src&&downloadFile
&近期下载过的用户:
&相关搜索:
&输入关键字，在本站238万海量源码库中尽情搜索：
&[] - 这个代码是一个很漂亮的进度条空间，值得看看。
&[] - 最简单的进度条程序,刚学windows界面的可以看一看
&[] - 一个Java网络OA办公系统。安装非常方便，对小心企业很有价值，作为学习也非常好。
&[] - 一个在ie实现文件上传下载的程序，用到了cos和jspSmartUpload组件，其中，cos组件实现上传，jspSmartUpload组件实现下载迅雷下载文件到99%点多的时候一下又变为0%的了,又重新开始下载是什么原因啊_百度知道【IOS学习】（10）
文件下载和进度
nodejs服务端下载图片
先改造一下我们的服务端程序，来下载一张图片，代码如下
//下载返回文件流
function download(req,res){
var downloadFilePath = &./1.jpg&;
var filename = path.basename(downloadFilePath);
var filesize = fs.readFileSync(downloadFilePath).length;
res.setHeader('Content-Disposition','filename=' + filename);//此处是关键
res.setHeader('Content-Length',filesize);
res.setHeader('Content-Type','application/octet-stream');
var fileStream = fs.createReadStream(downloadFilePath,{bufferSize:1024 * 1024});
fileStream.pipe(res,{end:true});
// res.writeHead(200, {'content-type': 'text/html'});
//改造一下handler方法，让url访问/download的时候进入文件下载的方法，返回文件流
handler:function(req,res){
console.log('handler');
console.log(req.url);
switch(req.url){
case '/' : get(req,res); break;
case &/download& : download(req,res); break;
iOS请求下载文件流
//http下载文件流
- (void)download{
//string 转 url编码
NSString *urlString = @&http://localhost:8001/download&;
NSURL *url = [NSURL URLWithString:[urlString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]]];
NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];
[connection start];
修改下请求委托，打印出请求头和收到的data，从而看一下收到的数据大小和数据请求进度相关内容。
//接收响应
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
NSLog(@&=================didReceiveResponse=================&);
NSHTTPURLResponse *resp = (NSHTTPURLResponse *)response;
NSLog(@&response:%@&,resp);
//接收响应
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
NSLog(@&=================didReceiveData=================&);
NSLog(@&data.length:%lu&,(unsigned long)data.length);
完成请求后打印出的结果如下：
21:48:50.694 network-demo[5] =================request redirectResponse=================
21:48:50.696 network-demo[5] request:&NSURLRequest: 0x7f91ea7948d0& { URL: http://localhost:8001/download }
21:48:50.706 network-demo[5] =================didReceiveResponse=================
21:48:50.706 network-demo[5] response:&NSHTTPURLResponse: 0x7f91ea5596f0& { URL: http://localhost:8001/download } { status code: 200, headers {
Connection = &keep-alive&;
&Content-Disposition& = &filename=1.jpg&;
&Content-Length& = 19557;
&Content-Type& = &application/octet-stream&;
Date = &Thu, 11 Feb :50 GMT&;
21:48:50.706 network-demo[5] =================didReceiveData=================
21:48:56.148 network-demo[5] data.length:19557
21:48:56.148 network-demo[5] =================connectionDidFinishLoading=================
可以看出：服务端在resqonse头中加入了content-length信息，告知整个流的大小，不过因为图片文件本身 较小，所以并没有分包，因此didReceiveData方法只调用了一次就完成了文件传递。大家可以试着修改下服务端返回的文件，
改为一个较大点的文件来试一次，这里我改成一个稍微大一些的图片，一张我自己hhkb键盘的美图~
downloadFilePath = &./IMG_0222.jpg&;&再试着发一次请求：
22:09:14.088 network-demo[5] =================request redirectResponse=================
22:09:14.089 network-demo[5] request:&NSURLRequest: 0x7f91ea54c5f0& { URL: http://localhost:8001/download }
22:09:14.118 network-demo[5] =================didReceiveResponse=================
22:09:14.119 network-demo[5] response:&NSHTTPURLResponse: 0x7f91ea591810& { URL: http://localhost:8001/download } { status code: 200, headers {
Connection = &keep-alive&;
&Content-Disposition& = &filename=IMG_0222.jpg&;
&Content-Length& = 1265302;
&Content-Type& = &application/octet-stream&;
Date = &Thu, 11 Feb :14 GMT&;
22:09:14.119 network-demo[5] =================didReceiveData=================
22:09:14.119 network-demo[5] data.length:65536
22:09:14.120 network-demo[5] =================didReceiveData=================
22:09:14.120 network-demo[5] data.length:65536
22:09:14.121 network-demo[5] =================didReceiveData=================
22:09:14.121 network-demo[5] data.length:65536
22:09:14.122 network-demo[5] =================didReceiveData=================
22:09:14.122 network-demo[5] data.length:131072
22:09:14.123 network-demo[5] =================didReceiveData=================
22:09:14.123 network-demo[5] data.length:132000
22:09:14.123 network-demo[5] =================didReceiveData=================
22:09:14.124 network-demo[5] data.length:392288
22:09:14.124 network-demo[5] =================didReceiveData=================
22:09:14.124 network-demo[5] data.length:65536
22:09:14.124 network-demo[5] =================didReceiveData=================
22:09:14.125 network-demo[5] data.length:65536
22:09:14.125 network-demo[5] =================didReceiveData=================
22:09:14.125 network-demo[5] data.length:65536
22:09:14.125 network-demo[5] =================didReceiveData=================
22:09:14.125 network-demo[5] data.length:65536
22:09:14.126 network-demo[5] =================didReceiveData=================
22:09:14.126 network-demo[5] data.length:151190
22:09:14.126 network-demo[5] =================connectionDidFinishLoading=================
可以看到didReceiveData委托被反复调用了很多次，我们可以通过&data.length:151190&和&Content-Length&
= 1265302;&就可以计算出流的下载进度。
//获取Content-Length
//[[((NSHTTPURLResponse *)response) allHeaderFields]objectForKey:@&Content-length&]
获取到完成的data后，可以直接把二进制的data转换成图片，代码如下：
UIImage *img = [UIImage imageWithData:data];
UIImageView *imageView = [[UIImageView alloc]initWithImage:img];
[imageView setFrame:CGRectMake(30, 30, 200, 200)];
[self.view addSubview:imageView];
上传文件和进度
服务端代码
服务端使用nodejs写的接受图片上传，重命名并保存文件，使用了formidable这个库完成图片获取，作为demo写的比较简单大家随意感受下。
//文件上传
function upload(req,res){
//创建上传表单
var form = new formidable.IncomingForm();
//设置编辑
form.encoding = 'utf-8';
//设置上传目录
form.uploadDir = './upload/';
form.keepExtensions =
//文件大小
form.maxFieldsSize = 10 * 1024 * 1024;
form.parse(req, function (err, fields, files) {
res.send(err);
// console.log(fields);
console.log(&=====&);
// console.log(files);
// console.log(files.file.name);
var extName = /\.[^\.]+/.exec(files.file.name);
var ext = Array.isArray(extName)
? extName[0]
//重命名，以防文件重复
var avatarName = uuid() +
//移动的文件目录
var newPath = form.uploadDir + avatarN
fs.renameSync(files.file.path, newPath);
// res.send('success');
var msg = { &status&:1,&msg&:&succeed&}
res.write(JSON.stringify(msg));
res.end();
http文件传输协议
来说点文件上传http协议的基础，前面的demo中，我们都没有设置请求头，因为我们都使用了默认的请求头&Content-Type:application/x-www-form-urlencoded&，这个请求头就是和html中的表单上传，如果get请求则
数据在url中，如果post请求，数据默认放在请求体中。然后默认的x-www-form-urlencoded头并不能上传文件，上传文件需要
设置头为：Content-Type:multipart/form-
boundary=YY&，boundary用于标识边界，可以自定义，使用时前面需要加上两个–，例如：”–YY”
我们在iOS上传文件时需要这样设置请求头
/** 设置请求头 */
// 请求体的长度
[request setValue:[NSString stringWithFormat:@&%zd&, body.length] forHTTPHeaderField:@&Content-Length&];
// 声明这个POST请求是个文件上传
[request setValue:@&multipart/form- boundary=YY& forHTTPHeaderField:@&Content-Type&];
[request setHTTPMethod:@&POST&];
iOS文件上传代码
我们上传一张稍微大点的图片，直接使用NSBundle对象读取项目中的文件，然后设置请求相关的委托方法，代码如下
//http上传文件流
- (void)upload{
#define Encode(str) [str dataUsingEncoding:NSUTF8StringEncoding]
NSURL *dataurl = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@&IMG_0222& ofType:@&jpg&]];
NSData *data = [NSData dataWithContentsOfURL:dataurl];
//string 转 url编码
NSString *urlString = @&http://localhost:8001/upload&;
NSURL *url = [NSURL URLWithString:[urlString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]]];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
/** 设置请求头 */
NSMutableData *body = [NSMutableData data];
//文件参数
// 参数开始的标志
[body appendData:Encode(@&--YY\r\n&)];
// name : 指定参数名(必须跟服务器端保持一致)
// filename : 文件名
NSString *disposition = [NSString stringWithFormat:@&Content-Disposition: form- name=\&%@\&; filename=\&%@\&\r\n&, @&file&, @&1.jpg&];
[body appendData:Encode(disposition)];
NSString *type = [NSString stringWithFormat:@&Content-Type: %@\r\n&, @&multipart/form-data&];
[body appendData:Encode(type)];
[body appendData:Encode(@&\r\n&)];
//添加图片数据
[body appendData:data];
[body appendData:Encode(@&\r\n&)];
[body appendData:Encode(@&--YY--\r\n&)];
//把body添加到request中
[request setHTTPBody:body];
/** 设置请求头 */
// 请求体的长度
[request setValue:[NSString stringWithFormat:@&%zd&, body.length] forHTTPHeaderField:@&Content-Length&];
// 声明这个POST请求是个文件上传
[request setValue:@&multipart/form- boundary=YY& forHTTPHeaderField:@&Content-Type&];
[request setHTTPMethod:@&POST&];
NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];
[connection start];
#pragma mark -网络请求委托
//请求失败
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{
NSLog(@&=================didFailWithError=================&);
NSLog(@&error:%@&,error);
- (nullable NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(nullable NSURLResponse *)response{
NSLog(@&=================request redirectResponse=================&);
NSLog(@&request:%@&,request);
return request;
//接收响应
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
NSLog(@&=================didReceiveResponse=================&);
NSHTTPURLResponse *resp = (NSHTTPURLResponse *)response;
NSLog(@&response:%@&,resp);
//接收响应
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
NSLog(@&=================didReceiveData=================&);
UIImage *img = [UIImage imageWithData:data];
UIImageView *imageView = [[UIImageView alloc]initWithImage:img];
[imageView setFrame:CGRectMake(30, 30, 200, 200)];
[self.view addSubview:imageView];
NSLog(@&data.length:%lu&,(unsigned long)data.length);
if (data) {
NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:nil];
NSLog(@&data:%@&,dic);
//上传数据委托，用于显示上传进度
- (void)connection:(NSURLConnection *)connection
didSendBodyData:(NSInteger)bytesWritten
totalBytesWritten:(NSInteger)totalBytesWritten
totalBytesExpectedToWrite:(NSInteger)totalBytesExpectedToWrite{
NSLog(@&=================totalBytesWritten=================&);
NSLog(@&didSendBodyData:%ld,totalBytesWritten:%ld,totalBytesExpectedToWrite:%ld&,(long)bytesWritten,(long)totalBytesWritten,(long)totalBytesExpectedToWrite);
NSLog(@&上传进度%ld%%&,(long)(totalBytesWritten*100 / totalBytesExpectedToWrite));
//完成请求
- (void)connectionDidFinishLoading:(NSURLConnection *)connection{
NSLog(@&=================connectionDidFinishLoading=================&);
大家可以看下代码，重点可以看下&upload方法，和&-
(void)connection:(NSURLConnection *)connection didSendBodyData:(NSInteger)bytesWritten totalBytesWritten:(NSInteger)totalBytesWritten&这个委托，观察如何设置文件上传的请求头和请求体，如果获取上传文件的进度。
程序运行后打印的结果
服务端日志，打印请求头
{ host: 'localhost:8001',
'content-type': 'multipart/form- boundary=YY',
connection: 'keep-alive',
accept: '*/*',
'user-agent': 'network-demo/1 CFNetwork/758.0.2 Darwin/14.5.0',
'content-length': '1265418',
'accept-language': 'en-us',
'accept-encoding': 'gzip, deflate' }
客户端日志：
13:05:07.330 network-demo[5] =================request redirectResponse=================
13:05:07.331 network-demo[5] request:&NSURLRequest: 0x7f9fa1691240& { URL: http://localhost:8001/upload }
13:05:07.339 network-demo[5] =================totalBytesWritten=================
13:05:07.339 network-demo[5] didSendBodyData:32768,totalBytesWritten:32768,totalBytesExpectedToWrite:1265418
13:05:07.339 network-demo[5] 上传进度2%
13:05:07.339 network-demo[5] =================totalBytesWritten=================
13:05:07.339 network-demo[5] didSendBodyData:32768,totalBytesWritten:65536,totalBytesExpectedToWrite:1265418
13:05:07.339 network-demo[5] 上传进度5%
13:05:07.340 network-demo[5] =================totalBytesWritten=================
13:05:07.340 network-demo[5] didSendBodyData:32768,totalBytesWritten:98304,totalBytesExpectedToWrite:1265418
13:05:07.340 network-demo[5] 上传进度7%
13:05:07.340 network-demo[5] =================totalBytesWritten=================
13:05:07.340 network-demo[5] didSendBodyData:32768,totalBytesWritten:131072,totalBytesExpectedToWrite:1265418
13:05:07.340 network-demo[5] 上传进度10%
13:05:07.340 network-demo[5] =================totalBytesWritten=================
13:05:07.341 network-demo[5] didSendBodyData:32768,totalBytesWritten:163840,totalBytesExpectedToWrite:1265418
13:05:07.341 network-demo[5] 上传进度12%
13:05:07.341 network-demo[5] =================totalBytesWritten=================
13:05:07.341 network-demo[5] didSendBodyData:32768,totalBytesWritten:196608,totalBytesExpectedToWrite:1265418
13:05:07.341 network-demo[5] 上传进度15%
13:05:07.341 network-demo[5] =================totalBytesWritten=================
13:05:07.341 network-demo[5] didSendBodyData:32768,totalBytesWritten:229376,totalBytesExpectedToWrite:1265418
13:05:07.342 network-demo[5] 上传进度18%
13:05:07.342 network-demo[5] =================totalBytesWritten=================
13:05:07.342 network-demo[5] didSendBodyData:32768,totalBytesWritten:262144,totalBytesExpectedToWrite:1265418
13:05:07.342 network-demo[5] 上传进度20%
13:05:07.342 network-demo[5] =================totalBytesWritten=================
13:05:07.342 network-demo[5] didSendBodyData:32768,totalBytesWritten:294912,totalBytesExpectedToWrite:1265418
13:05:07.342 network-demo[5] 上传进度23%
13:05:07.343 network-demo[5] =================totalBytesWritten=================
13:05:07.343 network-demo[5] didSendBodyData:32768,totalBytesWritten:327680,totalBytesExpectedToWrite:1265418
13:05:07.343 network-demo[5] 上传进度25%
13:05:07.343 network-demo[5] =================totalBytesWritten=================
13:05:07.343 network-demo[5] didSendBodyData:32768,totalBytesWritten:360448,totalBytesExpectedToWrite:1265418
13:05:07.343 network-demo[5] 上传进度28%
13:05:07.343 network-demo[5] =================totalBytesWritten=================
13:05:07.343 network-demo[5] didSendBodyData:32768,totalBytesWritten:393216,totalBytesExpectedToWrite:1265418
13:05:07.344 network-demo[5] 上传进度31%
13:05:07.344 network-demo[5] =================totalBytesWritten=================
13:05:07.344 network-demo[5] didSendBodyData:32768,totalBytesWritten:425984,totalBytesExpectedToWrite:1265418
13:05:07.344 network-demo[5] 上传进度33%
13:05:07.354 network-demo[5] =================totalBytesWritten=================
13:05:07.354 network-demo[5] didSendBodyData:32768,totalBytesWritten:458752,totalBytesExpectedToWrite:1265418
13:05:07.354 network-demo[5] 上传进度36%
13:05:07.354 network-demo[5] =================totalBytesWritten=================
13:05:07.354 network-demo[5] didSendBodyData:32768,totalBytesWritten:491520,totalBytesExpectedToWrite:1265418
13:05:07.354 network-demo[5] 上传进度38%
13:05:07.354 network-demo[5] =================totalBytesWritten=================
13:05:07.354 network-demo[5] didSendBodyData:32768,totalBytesWritten:524288,totalBytesExpectedToWrite:1265418
13:05:07.355 network-demo[5] 上传进度41%
13:05:07.355 network-demo[5] =================totalBytesWritten=================
13:05:07.355 network-demo[5] didSendBodyData:32768,totalBytesWritten:557056,totalBytesExpectedToWrite:1265418
13:05:07.355 network-demo[5] 上传进度44%
13:05:07.355 network-demo[5] =================totalBytesWritten=================
13:05:07.355 network-demo[5] didSendBodyData:32768,totalBytesWritten:589824,totalBytesExpectedToWrite:1265418
13:05:07.355 network-demo[5] 上传进度46%
13:05:07.356 network-demo[5] =================totalBytesWritten=================
13:05:07.356 network-demo[5] didSendBodyData:32768,totalBytesWritten:622592,totalBytesExpectedToWrite:1265418
13:05:07.356 network-demo[5] 上传进度49%
13:05:07.356 network-demo[5] =================totalBytesWritten=================
13:05:07.356 network-demo[5] didSendBodyData:32768,totalBytesWritten:655360,totalBytesExpectedToWrite:1265418
13:05:07.356 network-demo[5] 上传进度51%
13:05:07.356 network-demo[5] =================totalBytesWritten=================
13:05:07.357 network-demo[5] didSendBodyData:32768,totalBytesWritten:688128,totalBytesExpectedToWrite:1265418
13:05:07.357 network-demo[5] 上传进度54%
13:05:07.357 network-demo[5] =================totalBytesWritten=================
13:05:07.357 network-demo[5] didSendBodyData:32768,totalBytesWritten:720896,totalBytesExpectedToWrite:1265418
13:05:07.357 network-demo[5] 上传进度56%
13:05:07.357 network-demo[5] =================totalBytesWritten=================
13:05:07.357 network-demo[5] didSendBodyData:32768,totalBytesWritten:753664,totalBytesExpectedToWrite:1265418
13:05:07.357 network-demo[5] 上传进度59%
13:05:07.358 network-demo[5] =================totalBytesWritten=================
13:05:07.358 network-demo[5] didSendBodyData:32768,totalBytesWritten:786432,totalBytesExpectedToWrite:1265418
13:05:07.358 network-demo[5] 上传进度62%
13:05:07.358 network-demo[5] =================totalBytesWritten=================
13:05:07.358 network-demo[5] didSendBodyData:32768,totalBytesWritten:819200,totalBytesExpectedToWrite:1265418
13:05:07.359 network-demo[5] 上传进度64%
13:05:07.359 network-demo[5] =================totalBytesWritten=================
13:05:07.359 network-demo[5] didSendBodyData:32768,totalBytesWritten:851968,totalBytesExpectedToWrite:1265418
13:05:07.359 network-demo[5] 上传进度67%
13:05:07.359 network-demo[5] =================totalBytesWritten=================
13:05:07.359 network-demo[5] didSendBodyData:32768,totalBytesWritten:884736,totalBytesExpectedToWrite:1265418
13:05:07.359 network-demo[5] 上传进度69%
13:05:07.359 network-demo[5] =================totalBytesWritten=================
13:05:07.360 network-demo[5] didSendBodyData:32768,totalBytesWritten:917504,totalBytesExpectedToWrite:1265418
13:05:07.360 network-demo[5] 上传进度72%
13:05:07.360 network-demo[5] =================totalBytesWritten=================
13:05:07.360 network-demo[5] didSendBodyData:32768,totalBytesWritten:950272,totalBytesExpectedToWrite:1265418
13:05:07.360 network-demo[5] 上传进度75%
13:05:07.360 network-demo[5] =================totalBytesWritten=================
13:05:07.360 network-demo[5] didSendBodyData:32768,totalBytesWritten:983040,totalBytesExpectedToWrite:1265418
13:05:07.361 network-demo[5] 上传进度77%
13:05:07.374 network-demo[5] =================totalBytesWritten=================
13:05:07.375 network-demo[5] didSendBodyData:32768,totalBytesWritten:1015808,totalBytesExpectedToWrite:1265418
13:05:07.375 network-demo[5] 上传进度80%
13:05:07.375 network-demo[5] =================totalBytesWritten=================
13:05:07.375 network-demo[5] didSendBodyData:32768,totalBytesWritten:1048576,totalBytesExpectedToWrite:1265418
13:05:07.375 network-demo[5] 上传进度82%
13:05:07.375 network-demo[5] =================totalBytesWritten=================
13:05:07.375 network-demo[5] didSendBodyData:32768,totalBytesWritten:1081344,totalBytesExpectedToWrite:1265418
13:05:07.375 network-demo[5] 上传进度85%
13:05:07.375 network-demo[5] =================totalBytesWritten=================
13:05:07.376 network-demo[5] didSendBodyData:32768,totalBytesWritten:1114112,totalBytesExpectedToWrite:1265418
13:05:07.376 network-demo[5] 上传进度88%
13:05:07.376 network-demo[5] =================totalBytesWritten=================
13:05:07.376 network-demo[5] didSendBodyData:32768,totalBytesWritten:1146880,totalBytesExpectedToWrite:1265418
13:05:07.376 network-demo[5] 上传进度90%
13:05:07.376 network-demo[5] =================totalBytesWritten=================
13:05:07.376 network-demo[5] didSendBodyData:32768,totalBytesWritten:1179648,totalBytesExpectedToWrite:1265418
13:05:07.376 network-demo[5] 上传进度93%
13:05:07.377 network-demo[5] =================totalBytesWritten=================
13:05:07.377 network-demo[5] didSendBodyData:32768,totalBytesWritten:1212416,totalBytesExpectedToWrite:1265418
13:05:07.377 network-demo[5] 上传进度95%
13:05:07.377 network-demo[5] =================totalBytesWritten=================
13:05:07.377 network-demo[5] didSendBodyData:32768,totalBytesWritten:1245184,totalBytesExpectedToWrite:1265418
13:05:07.377 network-demo[5] 上传进度98%
13:05:07.377 network-demo[5] =================totalBytesWritten=================
13:05:07.377 network-demo[5] didSendBodyData:20234,totalBytesWritten:1265418,totalBytesExpectedToWrite:1265418
13:05:07.378 network-demo[5] 上传进度100%
13:05:07.404 network-demo[5] =================didReceiveResponse=================
13:05:07.405 network-demo[5] response:&NSHTTPURLResponse: 0x7f9fa16af610& { URL: http://localhost:8001/upload } { status code: 200, headers {
Connection = &keep-alive&;
Date = &Fri, 12 Feb :07 GMT&;
&Transfer-Encoding& = I
13:05:07.405 network-demo[5] =================didReceiveData=================
13:05:07.405 network-demo[5] data.length:28
13:05:07.405 network-demo[5] data:{
status = 1;
13:05:07.405 network-demo[5] =================connectionDidFinishLoading=================
大家可以看出如何读取文件上传的进度了。
总结异步http请求
使用异步http请求代码量复杂，但是有许多其他方式达不到的优点
使用文件流上传和下载，节省内存文件上传和下载有进度提示可以处理url验证可以取消在请求过程中取消请求（ 使用&[connection
cancel]&方法）
例如在demo中注释的一段代码：
- (void)connection:(NSURLConnection *)connection
didSendBodyData:(NSInteger)bytesWritten
totalBytesWritten:(NSInteger)totalBytesWritten
totalBytesExpectedToWrite:(NSInteger)totalBytesExpectedToWrite{
//测试取消上传
//if((totalBytesWritten*100 / totalBytesExpectedToWrite) & 50){[connection cancel];}
测试当上传进度到50%的时候，取消文件上传。
请用大一点的图片进行测试，因为这段代码是有bug的，当文件太小不会进入这个委托方法。
参考知识库
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