iOS --URLSession请求方法，以及文件下载

来源：互联网发布：土建预算软件下载编辑：程序博客网时间：2024/06/04 00:20

1主要包含三个请求方法：NSURLSessionDataTask，NSURLSessionDownloadTask，NSURLSessionUploadTask。

2.第一种请求方法－－GET

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

NSURL *url = [NSURLURLWithString:@"http://img03.tooopen.com/images/20160630/tooopen_sy_168334097794.jpg"];

NSURLRequest *request = [NSURLRequestrequestWithURL:url];

NSURLSession *session = [NSURLSessionsharedSession];

NSURLSessionDataTask *task = [session dataTaskWithRequest:request

completionHandler:^(NSData *_Nullable data,NSURLResponse *_Nullable response,NSError * _Nullable error) {

[selfshowImage:data];

NSLog(@"%@",data);

}];

[task resume];

}

-(void)showImage:(NSData *)data{

_imageView = [[UIImageViewalloc]initWithFrame:CGRectMake(10,5,100,100)];

_imageView.image = [UIImageimageWithData:data];

[self.viewaddSubview:_imageView];

}

3.第二种请求方法,如果要设置请求头就得创建Request。－－－GET

NSURLSession *session = [NSURLSessionsharedSession];

NSURLSessionDataTask *dataTask = [sessiondataTaskWithURL:[NSURLURLWithString:@"http://img03.tooopen.com/images/20160630/tooopen_sy_168334097794.jpg" ]completionHandler:^(NSData *_Nullable data,NSURLResponse *_Nullable response,NSError * _Nullable error) {

[self showImage:data];

}];

[dataTask resume];

4.第三种请求方法－－ POST

NSURL *url = [NSURLURLWithString:@"http://img03.tooopen.com/images/20160630/tooopen_sy_168334097794.jpg"];

NSURLSession *session = [NSURLSessionsharedSession];

NSMutableURLRequest *request = [NSURLRequestrequestWithURL:url];

request.HTTPMethod = @"POST";

request.HTTPBody = [@"username=123&ped=123"dataUsingEncoding:NSUTF8StringEncoding];

NSURLSessionDataTask *dataTask = [sessiondataTaskWithRequest:requestcompletionHandler:^(NSData *_Nullable data, NSURLResponse *_Nullable response, NSError * _Nullable error) {

NSLog(@"%@",data);

}];

[dataTask resume];

5.文件下载：默认存储在temp，需要手动存储在沙盒

NSURL *url = [NSURLURLWithString:@"http://img03.tooopen.com/images/20160630/tooopen_sy_168334097794.jpg"];

NSURLSession *session = [NSURLSessionsharedSession];

NSURLSessionDownloadTask *sessionTask = [sessiondownloadTaskWithURL:urlcompletionHandler:^(NSURL *_Nullable location, NSURLResponse * _Nullable response, NSError * _Nullable error) {

NSLog(@"-------ok!");

//剪切location的临时文件到真实位置

NSString *file = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory,NSUserDomainMask,YES)lastObject]stringByAppendingPathComponent:response.suggestedFilename];

NSFileManager *mgr = [NSFileManagerdefaultManager];

[mgr moveItemAtURL:location toURL:[NSURL fileURLWithPath:file] error:

nil];

}];

[sessionTask resume];

6.代理NSURLSessionDelegate

-(void)download1{

NSURLSession *session = [NSURLSessionsessionWithConfiguration:[NSURLSessionConfigurationdefaultSessionConfiguration]delegate:selfdelegateQueue:[[NSOperationQueuealloc]init]];

NSURLSessionDataTask *task = [sessiondataTaskWithRequest:[NSURLRequestrequestWithURL:[NSURLURLWithString:@""]]];

[task resume];

[task cancel];

[task suspend];

}

//接受到服务器的数据，可能会被多次调用。

-(void)URLSession:(NSURLSession *)session dataTask:(nonnullNSURLSessionDataTask *)dataTask didReceiveData:(nonnullNSData *)data{

}

//接收服务器的响应

-(void)URLSession:(NSURLSession *)session dataTask:(nonnullNSURLSessionDataTask *)dataTask didReceiveResponse:(nonnullNSURLResponse *)response completionHandler:(nonnullvoid (^)(NSURLSessionResponseDisposition))completionHandler{

//允许服务器的响应，才会继续接受服务器返回

completionHandler(NSURLSessionResponseAllow);

/**

* 补充NSUrlSessionTask创建的任务

* Task可以暂停盒挂起。

}

//请求完毕，成功／失败。

-(void)URLSession:(NSURLSession *)session task:(nonnullNSURLSessionTask *)task didCompleteWithError:(nullableNSError *)error{

}

7.注意点，只要是NSURLSessionTask创建的任务Task，就可以：

-(void)suspend;//暂停

-(void)cancel;//取消

-(void)resume;//恢复

@property(readonly,copy)NSError *error;//错误

@property(readonly,copy)NSURLResponse *response;//响应

8.大文件下载

-(void)downLoadBigFile{

NSURLSession *session = [NSURLSessionsessionWithConfiguration:[NSURLSessionConfigurationdefaultSessionConfiguration]delegate:selfdelegateQueue:[[NSOperationQueuealloc]init]];

NSURLSessionDownloadTask *downloadTask = [sessiondownloadTaskWithURL:[NSURLURLWithString:@""]];

[downloadTask resume];

}

-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didResumeAtOffset:(int64_t)fileOffset expectedTotalBytes:(int64_t)expectedTotalBytes{

}

//每当写入临时文件时就会调用

/**

* <#Description#>

* @param session <#session description#>

* @param downloadTask <#downloadTask description#>

* @param bytesWritten 这次写入

* @param totalBytesWritten 文件已写入

* @param totalBytesExpectedToWrite 文件总大小

-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite{

float progress = 1 * totalBytesWritten / totalBytesExpectedToWrite;

}

//下载完毕就会调用这个方法。

-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location{

NSString *file = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory,NSUserDomainMask,YES)lastObject]stringByAppendingPathComponent:downloadTask.response.suggestedFilename];

NSFileManager *mgr = [NSFileManagerdefaultManager];

[mgr moveItemAtURL:locationtoURL:[NSURLfileURLWithPath:file]error:nil];

}

-(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error{

}

9.断电下载：思路

-(NSURLSession *)session{

if (_session ==nil) {

_session = [NSURLSessionsessionWithConfiguration:[NSURLSessionConfigurationdefaultSessionConfiguration]delegate:selfdelegateQueue:[[NSOperationQueuealloc]init]];

}

return _session;

}

#define WCY [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)lastObject]stringByAppendingPathComponent:@"resumeData.temp" ]

-(NSData *)resumeData{

if (_resumeData ==nil) {

_resumeData = [NSDatadataWithContentsOfFile:WCY];

}

return_resumeData;

}

- (IBAction)Start:(id)sender {

if (self.resumeData) {

self.downloadTask = [_sessiondownloadTaskWithResumeData:self.resumeData];

}else{

_downloadTask = [_sessiondownloadTaskWithURL:[NSURLURLWithString:@""]];

}

[_downloadTaskresume];

}

- (IBAction)Pause:(id)sender {

// [_downloadTask suspend];

[_downloadTask cancelByProducingResumeData:^(NSData * _Nullable resumeData) {

/**

* rsumrData:记录上次下载的信息。

self.resumeData = resumeData;

// 可以将上一次保存的数据写入沙盒保存。

[resumeData writeToFile:WCYatomically:YES];

// 缓存空间

NSString *tmp = NSTemporaryDirectory();

}];

}

- (IBAction)GoOn:(id)sender {

self.downloadTask = [self.sessiondownloadTaskWithResumeData:self.resumeData];

[_downloadTask resume];

}

-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didResumeAtOffset:(int64_t)fileOffset expectedTotalBytes:(int64_t)expectedTotalBytes{

}

//每当写入临时文件时就会调用

/**

* <#Description#>

* @param session <#session description#>

* @param downloadTask <#downloadTask description#>

* @param bytesWritten 这次写入

* @param totalBytesWritten 文件已写入

* @param totalBytesExpectedToWrite 文件总大小

float progress = 1 * totalBytesWritten / totalBytesExpectedToWrite;

}

//下载完毕就会调用这个方法。

-(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location{

NSString *file = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory,NSUserDomainMask,YES)lastObject]stringByAppendingPathComponent:downloadTask.response.suggestedFilename];

NSFileManager *mgr = [NSFileManagerdefaultManager];

[mgr moveItemAtURL:locationtoURL:[NSURLfileURLWithPath:file]error:nil];

}

-(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error{

}

10.断电下载，调用的是请求头Response，

[[NSMutableURLRequestrequestWithURL:[NSURLURLWithString:@"www"]]setValue:@"10234"forHTTPHeaderField:@"Range"];

11.如果非正常下载失败，在下面的方法中保存数据。

-(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error{

// 如果因为其他原因失败，保存resumeData

self.resumeData = error.userInfo[NSURLSessionDownloadTaskResumeData];

}

12.文件的上传

- (NSURLSession *)session

{

if (!_session) {

NSURLSessionConfiguration *cfg = [NSURLSessionConfigurationdefaultSessionConfiguration];

cfg.timeoutIntervalForRequest =10;

// 是否允许使用蜂窝网络（手机自带网络）

cfg.allowsCellularAccess =YES;

_session = [NSURLSessionsessionWithConfiguration:cfg];

}

return_session;

}

- (void)viewDidLoad {

[superviewDidLoad];

}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

NSMutableURLRequest *request = [NSMutableURLRequestrequestWithURL:[NSURLURLWithString:@"http://120.25.226.186:32812/upload"]];

request.HTTPMethod = @"POST";

// 设置请求头(告诉服务器,这是一个文件上传的请求)

[request setValue:[NSStringstringWithFormat:@"multipart/form-data; boundary=%@",WCYBoundary]forHTTPHeaderField:@"Content-Type"];

// 设置请求体

NSMutableData *body = [NSMutableDatadata];

// 文件参数

// 分割线

[body appendData:WCYEncode(@"--")];

[body appendData:WCYEncode(WCYBoundary)];

[body appendData:WCYNewLine];

// 文件参数名

[body appendData:WCYEncode([NSStringstringWithFormat:@"Content-Disposition: form-data; name=\"file\"; filename=\"test.png\""])];

[body appendData:WCYNewLine];

// 文件的类型

[body appendData:WCYEncode([NSStringstringWithFormat:@"Content-Type: image/png"])];

[body appendData:WCYNewLine];

// 文件数据

[body appendData:WCYNewLine];

[body appendData:[NSDatadataWithContentsOfFile:@"/Users/Desktop/test.png"]];

[body appendData:WCYNewLine];

// 结束标记

--分割线--\r\n

[body appendData:WCYEncode(@"--")];

[body appendData:WCYEncode(WCYBoundary)];

[body appendData:WCYEncode(@"--")];

[body appendData:WCYNewLine];

[[self.sessionuploadTaskWithRequest:request fromData:body completionHandler:^(NSData *data,NSURLResponse *response, NSError *error) {

NSLog(@"-------%@", [NSJSONSerializationJSONObjectWithData:data options:kNilOptionserror:nil]);

}] resume];

}

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