- (void)requst:(NSString*)url{
//默认配置
//    NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
//    //AFN3.0+基于封住URLSession的句柄
AFURLSessionManager *manager = [[AFURLSessionManager alloc] initWithSessionConfiguration:configuration];
__weak typeof(manager) weakmanager = manager;
//    __weak typeof(self) weakSelf = self
// AFURLSessionManager *manager = [AppDelegate sharedManager];

//请求
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:url]];
//下载Task操作
NSURLSessionDownloadTask *downloadTask = [manager downloadTaskWithRequest:request progress:nil destination:^NSURL * _Nonnull(NSURL * _Nonnull targetPath, NSURLResponse * _Nonnull response) {
//- block的返回值, 要求返回一个URL, 返回的这个URL就是文件的位置的路径
NSString *cachesPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
NSString *path = [cachesPath stringByAppendingPathComponent:response.suggestedFilename];



return [NSURL fileURLWithPath:path];
} completionHandler:^(NSURLResponse * _Nonnull response, NSURL * _Nullable filePath, NSError * _Nullable error) {
NSLog(@"错误信息%@",error);
//设置下载完成操作
// filePath就是你下载文件的位置，你可以解压，也可以直接拿来使用
if ([[NSFileManager defaultManager] fileExistsAtPath:[filePath path]]) {
NSString *zipPath = [filePath path];// 将NSURL转成NSString
}
//        [weakmanager invalidateSessionCancelingTasks:YES];
}];
[downloadTask resume];
}