我从一个URL中检索JSON数据,该URL的格式如下:
{"zoneresponse":
{"tasks":
[{"datafield1":"datafor1",
"datafield2":"datafor2",
"datafield3":"datafor3",...
}]
}}
我无法控制该结构,因为它来自私有API。
如何在现有对象的选定数据字段中插入数据?
我已经尝试过了:
self.responseData = [NSMutableData data];
//testingURL is the api address to the specific object in tasks
NSURL *url = [NSURL URLWithString:testingURL];
NSMutableDictionary *params = [[NSMutableDictionary alloc] init];
[[[params objectForKey:@"zoneresponse"] objectForKey:@"tasks"] setValue:@"HelloWorld" forKey:@"datafield1"];
//HAVE TRIED setObject: @"" objectForKey: @"" as well
//*****PARAMS IS EMPTY WHEN PRINTED IN NSLog WHICH IS PART OF THE ISSUE - SETTING VALUE DOES NOT WORK
NSError * error = nil;
NSLog(@"Params is %@", params);
NSData *requestdata = [NSJSONSerialization dataWithJSONObject:params options:0 error:&error];
NSMutableURLRequest *request;
request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:@"POST"];
[request setValue:[NSString stringWithFormat:@"%d", [requestdata length]] forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/json" forHTTPHeaderField:@"Accept"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody:requestdata];
NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];
if(conn) {
NSLog(@"Connection Successful, connection is: %@", conn);
} else {
NSLog(@"Connection could not be made");
}
正在建立连接,但打印时字典参数为空( setValue未显示),并且没有在我选择的字段中输入任何数据。
我已经检查了这些链接,但没有解释它是否会插入到正确的字段中,并暗示它将创建一个新对象,而不是更新现有对象。
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委托方法
//any time a piece of data is received we will append it to the responseData object
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[self.responseData appendData:data];
NSError *jsonError;
id responseDict =
[NSJSONSerialization JSONObjectWithData:self.responseData
options:NSJSONReadingAllowFragments
error:&jsonError];
NSLog(@"Did Receive data %@", responseDict);
}
//if there is some sort of error, you can print the error or put in some other handling here, possibly even try again but you will risk an infinite loop then unless you impose some sort of limit
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
// Clear the activeDownload property to allow later attempts
self.responseData = nil;
NSLog(@"Did NOT receive data ");
}
//connection has finished, the requestData object should contain the entirety of the response at this point
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSError *jsonError;
id responseDict =
[NSJSONSerialization JSONObjectWithData:self.responseData
options:NSJSONReadingAllowFragments
error:&jsonError];
if(responseDict)
{
NSLog(@"%@", responseDict);
}
else
{
NSLog(@"%@", [jsonError description]);
}
//clear out our response buffer for future requests
self.responseData = nil;
}
这里的第一个方法说明接收数据时使用了"Did Receive data (null)",连接没有错误,但是最后一个方法输出错误消息"JSON text not start with array or object and option to allow fragments not set.",这是可以理解的,因为没有发送数据或对象。
如何将数据插入现有对象的选定字段?
https://stackoverflow.com/questions/29669296
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