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NSURLSession初识

NSURLSession初识

作者: Mr丶炎 | 来源:发表于2016-07-31 09:13 被阅读45次

1、 NSURLSessionDataTask,请求
2、NSURLSessionDownloadTask,下载
3、监听文件下载进度
4、当前运行程序时下载,退出程序后失效
5、NSURLSessionUploadTask,文件上传

使用步骤

  • 使用NSURLSession对象创建Task,然后执行Tack
  • Task类型, 各自有不同的任务,dataTask主要是传输数据,发送网络请求,uploadTask专门用来上传任务的,downloadTask主要是下载任务
类型.png
  • NSURLSessionDataTask
    get请求
- (void)get {
    
    // 获得NSURLSession对象
    NSURLSession *session = [NSURLSession sharedSession];
    
    // 创建任务
    NSURLSessionDataTask *task = [session dataTaskWithRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://120.25.226.186:32812/login?username=123&pwd=123&type=JSON"]] completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        
        NSLog(@"%@", [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil]);
        
    }];
    
    // 启动任务
    [task resume];
    

}

- (void)get2 {
    // 获得NSURLSession对象
    NSURLSession *session = [NSURLSession sharedSession];

     NSURLSessionDataTask *task = [session dataTaskWithURL:[NSURL URLWithString:@"http://120.25.226.186:32812/login?username=123&pwd=123&type=JSON"] completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
         
         NSLog(@"%@", [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil]);
         
    }];
    
    // 启动任务
    [task resume];

}

post请求

  • 请求参数要放在请求体里面,放在URL后面不识别
- (void)post {
    
    // 获得NSURLSession对象
    NSURLSession *session = [NSURLSession sharedSession];
    
    // 创建请求, 如果是post请求,请求参数要放在请求体里面,放在URL后面不识别
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://120.25.226.186:32812/login"]];
    request.HTTPMethod = @"POST";
    request.HTTPBody = [@"username=520it&pwd=520it" dataUsingEncoding:NSUTF8StringEncoding];
    
    // 创建任务
    NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        
        NSLog(@"%@", [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil]);
        
    }];
    
    // 启动任务
    [task resume];
    
}

  • NSURLSessionDownloadTask
    下载文件,因为默认它帮你下载到tmp文件中,所有我们需要自己移动到caches文件下
- (void)downLoad {
 
    // 获得NSURLSession对象
    NSURLSession *session = [NSURLSession sharedSession];
    
    // 获得下载任务
    NSURLSessionDownloadTask *task = [session downloadTaskWithURL:[NSURL URLWithString:@"http://120.25.226.186:32812/resources/videos/minion_01.mp4"] completionHandler:^(NSURL * _Nullable location, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        
        // 文件将来存放的真实路径
        NSString *file = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:response.suggestedFilename];
        
        // 剪切location的临时文件到真实路径
        NSFileManager *mgr = [NSFileManager defaultManager];
        
        [mgr moveItemAtURL:location toURL:[NSURL fileURLWithPath:file] error:nil];
        
    }];
    
    // 启动任务
    [task resume];
    
}

  • 监听文件的下载进度,需要实现代理协议
    NSURLSessionDownloadDelegate
- (void)downLoad {
 
    // 获得NSURLSession对象
    NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[[NSOperationQueue alloc] init]];
    
    // 获得下载任务
    NSURLSessionDownloadTask *task = [session downloadTaskWithURL:[NSURL URLWithString:@"http://120.25.226.186:32812/resources/videos/minion_01.mp4"]];
    
    // 启动任务
    [task resume];
    
}

#pragma mark - NSURLSessionDownloadDelegate
/**
 * 下载完毕
 */

- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error {
    NSLog(@"%s", __func__);
}

/**
 * 下载完毕,就会调用一次
 */

- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location {
    
    // 文件将来存放的真实路径
    NSString *file = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:downloadTask.response.suggestedFilename];
    
    // 剪切location的临时文件到真实路径
    NSFileManager *mgr = [NSFileManager defaultManager];
    
    [mgr moveItemAtURL:location toURL:[NSURL fileURLWithPath:file] error:nil];

    
}


/**
 * 每当写入数据到临时文件中时,就会调用一次
 * totalBytesExpectedToWrite 总大小
 * totalBytesWritten 已经写入的大小
 * bytesWritten 这次写入多少
 */
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite {
    
    NSLog(@"----%f---", 1.0 * totalBytesWritten / totalBytesExpectedToWrite);
    
}

/**
 * 做断点下载
 */

- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didResumeAtOffset:(int64_t)fileOffset expectedTotalBytes:(int64_t)expectedTotalBytes {
    NSLog(@"%s", __func__);
}

当前运行时下载.png
  • 当前运行程序时下载,退出程序后失效。执行过程中下载文件在子线程,那么progress要在主线程显示
子线程.png
#import "ViewController.h"

@interface ViewController () <NSURLSessionDownloadDelegate>

@property (weak, nonatomic) IBOutlet UIProgressView *progressView;

/** 下载任务 */
@property (nonatomic, strong) NSURLSessionDownloadTask *task;

@end

@implementation ViewController

/** 开始下载 */
- (IBAction)start:(id)sender {
    
    // 获得NSURLSession对象
    NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[[NSOperationQueue alloc] init]];
    
    // 获得下载任务
    self.task = [session downloadTaskWithURL:[NSURL URLWithString:@"http://120.25.226.186:32812/resources/videos/minion_01.mp4"]];
    
    // 启动任务
    [self.task resume];
    
}

/** 暂停下载 */
- (IBAction)pause:(id)sender {
    
    [self.task suspend];
}

/** 继续下载 */
- (IBAction)goOn:(id)sender {
    
    [self.task resume];
}



- (void)viewDidLoad {
    [super viewDidLoad];
    
    NSLog(@"%@", [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject]);
    
}

#pragma mark - NSURLSessionDownloadDelegate
/**
 * 下载完毕
 */

- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error {
    NSLog(@"%s", __func__);
}

/**
 * 下载完毕,就会调用一次
 */

- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location {
    
    // 文件将来存放的真实路径
    NSString *file = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:downloadTask.response.suggestedFilename];
    
    // 剪切location的临时文件到真实路径
    NSFileManager *mgr = [NSFileManager defaultManager];
    
    [mgr moveItemAtURL:location toURL:[NSURL fileURLWithPath:file] error:nil];

    
}

/**
 * 每当写入数据到临时文件中时,就会调用一次
 * totalBytesExpectedToWrite 总大小
 * totalBytesWritten 已经写入的大小
 * bytesWritten 这次写入多少
 */
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite {
    
    NSLog(@"-%@---%f---", [NSThread currentThread], 1.0 * totalBytesWritten / totalBytesExpectedToWrite);

    // 回到主线程
    [[NSOperationQueue mainQueue] addOperationWithBlock:^{
        self.progressView.progress = 1.0 * totalBytesWritten / totalBytesExpectedToWrite;
    }];
    
}

/**
 * 做断点下载
 */

- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didResumeAtOffset:(int64_t)fileOffset expectedTotalBytes:(int64_t)expectedTotalBytes {
    NSLog(@"%s", __func__);
}



@end

  • 文件上传,太多细节了,很多参数必不可少
#import "ViewController.h"

#define XMGBoundary @"----WebKitFormBoundarytMDJ32dISJeAmwM9"
#define XMGEncode(string) [string dataUsingEncoding:NSUTF8StringEncoding]
#define XMGNewLine [@"\r\n" dataUsingEncoding:NSUTF8StringEncoding]

@interface ViewController () <NSURLSessionTaskDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    // 获得NSURLSession对象
    NSURLSession *session = [NSURLSession sharedSession];
    
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"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:[NSString stringWithFormat:@"multipart/form-data; boundary=%@", XMGBoundary] forHTTPHeaderField:@"Content-Type"];
    
    // 设置请求体
    NSMutableData *body = [NSMutableData data];
    
    // 请求参数
    // 分割线
    [body appendData:XMGEncode(@"--")];
    [body appendData:XMGEncode(XMGBoundary)];
    [body appendData:XMGNewLine];
    
    // 文件参数名
    [body appendData:XMGEncode([NSString stringWithFormat:@"Content-Disposition: form-data; name=\"file\"; filename=\"test.png\""])];
    [body appendData:XMGNewLine];
    
    // 文件类型
    [body appendData:XMGEncode([NSString stringWithFormat:@"Content-Type: image/png"])];
    [body appendData:XMGNewLine];
    
    // 文件数据
    [body appendData:XMGNewLine];
    [body appendData:[NSData dataWithContentsOfFile:@"/Users/mac2/Desktop/test.png"]];
    [body appendData:XMGNewLine];
    
    // 结束标记
    /**
     --分割线--\r\n
     */
    [body appendData:XMGEncode(@"--")];
    [body appendData:XMGEncode(XMGBoundary)];
    [body appendData:XMGEncode(@"--")];
    [body appendData:XMGNewLine];
    
    // 执行任务
    [[session uploadTaskWithRequest:request fromData:body completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        
        NSLog(@"---%@---", [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil]);
        
    }] resume];
    
}

@end

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