因为我想要看看 NSURLSession 的工作原理。

AppDelegate.m

确保将它添加到您的应用程序代理中。它将确保您的应用程序挂起时完成上传/下载的完成块。

#import "TSNetworking.h"

- (void)application:(UIApplication *)application
handleEventsForBackgroundURLSession:(NSString *)identifier
completionHandler:(void (^)())completionHandler
{
  [TSNetworking backgroundSession].sessionCompletionHandler = completionHandler;
}

初始化

[[TSNetworking foregroundSession] setBaseURLString:kBaseURLString];
[[TSNetworking foregroundSession] setBasicAuthUsername:nil withPassword:nil];
[[TSNetworking foregroundSession] addSessionHeaders:@{@"all":@"nightlong"}]; // sticks around forever, used in each request

这些设置在应用程序运行期间有效

维护

[[TSNetworking foregroundSession] removeAllSessionHeaders];

使用哪个？

[TSNetworking foregroundSession] /* for all your regular GETs, POSTs. You are given an NSObject as the result. 
OR for uploading NSData in the foreground.  */
- OR -
[TSNetworking backgroundSession] /* for all your background downloads and (local NSURL) uploads. Uses funky new NSURLSession features to run while your apps if minimized, no need to pause and serialise your downloads on applicationDidEnterBackground */

警告

成功和错误块在苹果决定线程上执行。如果您在这些块中进行 UI 变更，建议您使用 dispatch_async 并获取主队列。对新手玩家的警告：永远不要在块内部引用 self，使用这种样式以避免保留循环

__weak typeof(self) weakSelf = self;
TSNetworkSuccessBlock successBlock = ^(NSObject *resultObject, NSMutableURLRequest *request, NSURLResponse *response) {
    __strong typeof(weakSelf) strongSelf = weakSelf;
    [strongSelf sendAMessage];
};

获取

TSNetworkSuccessBlock successBlock = ^(NSObject *resultObject, NSMutableURLRequest *request, NSURLResponse *response) {
    NSLog(@"We got ourselves a: %@", resultObject);
};

TSNetworkErrorBlock errorBlock = ^(NSObject *resultObject, NSError *error, NSMutableURLRequest *request, NSURLResponse *response) {
    switch (error.code) {
        case 401:
            NSLog(@"Mannn");
            break;

        default:
            break;
    }
};

[[TSNetworking foregroundSession] performDataTaskWithRelativePath:nil
                                                   withMethod:HTTP_METHOD_GET
                                               withParameters:nil
                                         withAddtionalHeaders:@{@"Content-Type":@"application/json"}
                                                  withSuccess:successBlock
                                                    withError:errorBlock];

提交

TSNetworkSuccessBlock successBlock = ^(NSObject *resultObject, NSMutableURLRequest *request, NSURLResponse *response) {
    // resultObject will probably be a JSON dictionary 
};

TSNetworkErrorBlock errorBlock = ^(NSObject *resultObject, NSError *error, NSMutableURLRequest *request, NSURLResponse *response) {
    NSLog(@"%@", error.localizedDescription); // tells you what the problem was, i.e. offline
};

[[TSNetworking foregroundSession] performDataTaskWithRelativePath:nil
                                                   withMethod:HTTP_METHOD_POST
                                               withParameters:@{@"key": @"value"}
                                         withAddtionalHeaders:nil
                                                  withSuccess:successBlock
                                                    withError:errorBlock];

下载

TSNetworkSuccessBlock successBlock = ^(NSObject *resultObject, NSMutableURLRequest *request, NSURLResponse *response) {
    // sweet, resultObject is a (local) NSURL for what we just downloaded
};

TSNetworkErrorBlock errorBlock = ^(NSObject *resultObject, NSError *error, NSMutableURLRequest *request, NSURLResponse *response) {
    //same old handling
};

TSNetworkDownloadTaskProgressBlock progressBlock = ^(int64_t bytesWritten, int64_t totalBytesWritten, int64_t totalBytesExpectedToWrite) {
    NSLog(@"Download written: %lld, total written: %lld, total expected: %lld", bytesWritten, totalBytesWritten, totalBytesExpectedToWrite);
};

NSURLSessionDownloadTask *task = [[TSNetworking backgroundSession] downloadFromFullPath:@"https://archive.org/download/1mbFile/1mb.mp4"
                                                                                 toPath:destinationPath
                                                                   withAddtionalHeaders:nil
                                                                      withProgressBlock:progressBlock
                                                                            withSuccess:successBlock
                                                                              withError:errorBlock];

上传

NSString *sourcePath = [[NSBundle mainBundle] pathForResource:@"ourLord" ofType:@"jpg"];

TSNetworkSuccessBlock successBlock = ^(NSObject *resultObject, NSMutableURLRequest *request, NSURLResponse *response) {
    //resultObject is whatever the server responded with, could be JSON, HTML, whatever
};

TSNetworkErrorBlock errorBlock = ^(NSObject *resultObject, NSError *error, NSMutableURLRequest *request, NSURLResponse *response) {
    //same old handling
};

TSNetworkDownloadTaskProgressBlock progressBlock = ^(int64_t bytesWritten, int64_t totalBytesWritten, int64_t totalBytesExpectedToWrite) {
    NSLog(@"uploaded: %lld, total written: %lld, total expected: %lld", bytesWritten, totalBytesWritten, totalBytesExpectedToWrite);
};

NSURLSessionUploadTask *uploadTask = [[TSNetworking backgroundSession] uploadInBackgroundFromLocalPath:sourcePath
                                                                                                toPath:kMultipartUpload
                                                                                  withAddtionalHeaders:nil
                                                                                     withProgressBlock:progressBlock
                                                                                           withSuccess:successBlock
                                                                                             withError:errorBlock];

// or

NSFileManager *fm = [NSFileManager new];
NSData *data = [fm contentsAtPath:sourcePath];

[[TSNetworking foregroundSession] uploadInForegroundData:data
                                              toPath:kMultipartUpload
                                withAddtionalHeaders:nil
                                   withProgressBlock:progressBlock
                                         withSuccess:successBlock
                                           withError:errorBlock];