Ios 使用JSON通过POST从NSURLSession获取数据
由于NSURLConnection已被弃用,我需要转到NSURLSession。我有一个URL和一些数据需要作为JSON输入。那么结果应该是JSON返回。我看到这样的情况:Ios 使用JSON通过POST从NSURLSession获取数据,ios,objective-c,json,ios9,nsurlsession,Ios,Objective C,Json,Ios9,Nsurlsession,由于NSURLConnection已被弃用,我需要转到NSURLSession。我有一个URL和一些数据需要作为JSON输入。那么结果应该是JSON返回。我看到这样的情况: NSError *error; NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration]; NSURLSession *session = [NSURLSession sessionW
NSError *error;
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];
NSURL *url = [NSURL URLWithString:@"[JSON SERVER"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:60.0];
[request addValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
[request addValue:@"application/json" forHTTPHeaderField:@"Accept"];
[request setHTTPMethod:@"POST"];
NSDictionary *mapData = [[NSDictionary alloc] initWithObjectsAndKeys: @"TEST IOS", @"name",
@"IOS TYPE", @"typemap",
nil];
NSData *postData = [NSJSONSerialization dataWithJSONObject:mapData options:0 error:&error];
[request setHTTPBody:postData];
NSURLSessionDataTask *postDataTask = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
}];
[postDataTask resume];
我认为这是正确的方法吗
我的要求是:
1.将我的键值对转换为JSON。
2.将URL和JSON传递给可重用函数。
3.获取返回的JSON数据。
4.解析返回的JSON数据
NSURLSession
和NSMutableURLRequest
对象:
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setHTTPMethod:@"POST"];
[request addValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
[request addValue:@"application/json" forHTTPHeaderField:@"Accept"];
// choose the right type for your value.
NSDictionary *postDict = @{@"key1": value1, @"key2": value2};
NSData *postData = [NSJSONSerialization dataWithJSONObject:postDict options:0 error:nil];
[request setURL:[NSURL URLWithString:@"JSON SERVER"];
[request setHTTPBody:postData];
NSURLSessionDataTask *postDataTask = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
}];
[postDataTask resume];
completionHandler
中解析返回的JSON数据:
if (!error) {
NSDictionary *responseDict = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
} else {
// error code here
}
responseDict
是解析的数据。例如,如果服务器返回
{
"message":"Your messsage",
"data1":value1,
"data2":value2
}
您可以使用
[responseDict objectForKey:@"data1"];
希望我的回答有帮助。让方法的调用方提供一个完成处理程序,该处理程序处理返回的数据并更新UI以指示完成 您可以复制SDK中找到的模式,如下所示:
- (void)makeRequest:(NSString *)param completion:(void (^)(NSDictionary *, NSError *))completion;
这样实施:
// in the same scope
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];
- (void)makeRequest:(NSString *)param
completion:(void (^)(NSDictionary *, NSError *))completion {
// your OP code goes here, e.g.
NSError *error;
NSMutableURLRequest *request = // maybe the param is the url for this request
// use the already initialized session
NSURLSessionDataTask *postDataTask = [session dataTaskWithRequest:request
completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
// call the completion handler in EVERY code path, so the caller is never left waiting
if (!error) {
// convert the NSData response to a dictionary
NSDictionary *dictionary = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
if (error) {
// there was a parse error...maybe log it here, too
completion(nil, error);
} else {
// success!
completion(dictionary, nil);
}
} else {
// error from the session...maybe log it here, too
completion(nil, error);
}
}];
[postDataTask resume];
}
// update the UI here to say "I'm busy making a request"
// call your function, which you've given a completion handler
[self makeRequest:@"https://..." completion:^(NSDictionary *someResult, NSError *error) {
// here, update the UI to say "Not busy anymore"
if (!error) {
// update the model, which should cause views that depend on the model to update
// e.g. [self.someUITableView reloadData];
} else {
// handle the error
}
}];
调用此方法的代码如下所示:
// in the same scope
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];
- (void)makeRequest:(NSString *)param
completion:(void (^)(NSDictionary *, NSError *))completion {
// your OP code goes here, e.g.
NSError *error;
NSMutableURLRequest *request = // maybe the param is the url for this request
// use the already initialized session
NSURLSessionDataTask *postDataTask = [session dataTaskWithRequest:request
completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
// call the completion handler in EVERY code path, so the caller is never left waiting
if (!error) {
// convert the NSData response to a dictionary
NSDictionary *dictionary = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
if (error) {
// there was a parse error...maybe log it here, too
completion(nil, error);
} else {
// success!
completion(dictionary, nil);
}
} else {
// error from the session...maybe log it here, too
completion(nil, error);
}
}];
[postDataTask resume];
}
// update the UI here to say "I'm busy making a request"
// call your function, which you've given a completion handler
[self makeRequest:@"https://..." completion:^(NSDictionary *someResult, NSError *error) {
// here, update the UI to say "Not busy anymore"
if (!error) {
// update the model, which should cause views that depend on the model to update
// e.g. [self.someUITableView reloadData];
} else {
// handle the error
}
}];
注意两件事:(1)返回类型为
void
,调用方不希望从该方法返回任何内容,并且在调用它时不进行赋值。“返回”的数据作为参数提供给完成处理程序,完成处理程序在asnych请求完成后调用,(2)完成处理程序的签名与调用方在完成块^(NSDictionary*,NSError*)
中声明的完全匹配,这只是一个建议,典型的网络请求。您不只是使用Alamofire有什么原因吗?它使网络变得非常简单。你试过上面的代码吗?它起作用了吗?除了希望有人复制/粘贴您的代码并对其进行测试之外,您在这里并没有提出任何真正的问题。至于“这是正确的方法吗?”我会是一个聪明的亚历克,说不,迁移到斯威夫特:)看起来不错。你有问题吗?在completionHandler中执行步骤3和4。考虑给出这个代码出现一个完成块的方法,这样调用方可以异步地得到结果。顺便说一句,如果您正在处理多个请求,我还建议您不要每次都实例化一个新的会话对象。实例化会话对象一次。另外,您真的实现了委托方法吗?如果不是,我只需使用sessionWithConfiguration
实例化,而不使用delegate
或delegateQueue
,或者使用sharedSession
。这取决于您。如果您没有以任何方式修改会话配置,也没有使用委托,则应使用共享会话。这就是它的目的。基本上,它的行为类似于NSURLConnection…@danh和Rob如果我把它放在方法调用中,创建块的语法是什么?(void)getAPI?解释得很好。非常感谢。