如何在ios中解析json

Question

我是 ios 开发的新手，所以我需要从基础层面逐步指导，我使用了很多链接，但所有链接都为我提供了直接的项目代码，然后开始我需要了解所有的想法是如何像布局和开发一样工作的。

Answer 1

你可以使用 NSJSONSerialization 类 https://developer.apple.com/library/ios/documentation/Foundation/Reference/NSJSONSerialization_Class/

NSDictionary *responseObject = [NSJSONSerialization
JSONObjectWithData:responseData options:self.readingOptions   
error:&serializationError];

Answer 2

对于 json 解析，您可以使用 AFNetworking。 它非常简单和有用的平台，具有简单和复杂的 json 解析。

您可以使用以下链接了解更多信息

http://www.raywenderlich.com/59255/afnetworking-2-0-tutorial

Answer 3

对于json解析，您可以使用简单的NSJsonSerialization。您可以使用json解析post将数据发布到服务器，也可以使用json解析GET方法从服务器获取数据。

将数据发布到服务器的第一个 POST

//STEP 1 :Here give YOUR URL instead of my URL
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:@"http://192.168.3.128:8050/RestWebService/rest/person"]];


//STEP 2 :create the Method "POST"
[request setHTTPMethod:@"POST"];

//STEP 3 :Pass The String to server(YOU SHOULD GIVE YOUR PARAMETERS INSTEAD OF MY PARAMETERS)
NSString *userUpdate =[NSString strin gWithFormat:@"user_email=%@&user_login=%@&user_pass=%@&  last_upd_by=%@&user_registered=%@&",txtemail.text,txtuser1.text,txtpass1.text,txtuser1.text,datestr,nil];

//STEP 4 :Check The Value what we passed
NSLog(@"the data Details is =%@", userUpdate);

//STEP 5 :Convert the String to Data
NSData *data1 = [userUpdate dataUsingEncoding:NSUTF8StringEncoding];

//STEP 7 :Apply the data to the body
[request setHTTPBody:data1];

//STEP 8 :Create the response and Error
NSError *err;
NSURLResponse *response;

//STEP 9 :send synchronous request to server  
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&err];

//STEP 10 :getting the response 
NSString *resSrt = [[NSString alloc]initWithData:responseData encoding:NSASCIIStringEncoding];

//STEP 11:Check whether we got the Response or Not
NSLog(@"got response==%@", resSrt);
if(resSrt)
{
  NSLog(@"got response");
}
else
{
   NSLog(@"faield to connect");
}

第二次使用 NSJsonSerialization 方法从服务器获取响应

//STEP 1 :Here give YOUR URL instead of my URL
NSMutableURLRequest *request=[NSMutableURLRequest requestWithURL:[NSURL  URLWithString:@"http://api.worldweatheronline.com/free/v1/search.ashx?query=London&num_of_results=3&format=json&key=xkq544hkar4m69qujdgujn7w"]];

//STEP 2 :create the Method "GET" 
[request setHTTPMethod:@"GET"];

//STEP 3 : set request as Json format value type 
[request setValue:@"application/json;charset=UTF-8" forHTTPHeaderField:@"content-type"];

//STEP 4 : Create the response and Error 
NSError *err;
NSURLResponse *response;

//STEP 5 :send synchronous request to server  
NSData *responseData = [NSURLConnection sendSynchronousRequest:request   returningResponse:&response error:&err];

//You need to check response.Once you get the response copy that and paste in ONLINE JSON VIEWER.If you do this clearly you can get the correct results.    

//After that it depends upon the json format whether it is DICTIONARY or ARRAY 

//STEP 6 :Get the response to dictionary or array depends upon the response
NSDictionary *jsonArray = [NSJSONSerialization JSONObjectWithData:responseData options: NSJSONReadingMutableContainers error: &err];