Question

我使用NSJSONSerialization的{{1}}来解析从服务器返回的JSON数据。

现在我使用的选项参数：JSONObjectWithData:data options: error:。您可以在下面查看实际的JSON（我相信问题所在）。

我收到的错误消息是：

错误Domain = NSCocoaErrorDomain Code = 3840“操作无法完成。（Cocoa error 3840.）”（字符0周围的值无效。）UserInfo = 0x6895da0 {NSDebugDescription =字符0周围的值无效。}

知道怎么解决吗？

JSON =

NSJSONReadingAllowFragments

Answer 1

可能你有一些你看不到的不可打印的角色。试试这个：

NSData *jsonData = ...
const unsigned char *ptr = [data bytes];

for(int i=0; i<[data length]; ++i) {
  unsigned char c = *ptr++;
  NSLog(@"char=%c hex=%x", c, c);
}

验证您在数据的开头或结尾没有不可打印的字符。

编辑：澄清一下，只需在您的JSON字典上运行上述内容 - 无法解析的字典。

Answer 2

我已经意识到这个问题是这样一个事实，即从URL返回的是一个HTML页面，所有这些html，head和body标签都围绕着实际的响应，所以它无法被解析。关于如何从响应中删除HTML标记（在将其更改为字符串之后），这是一个很好的Q＆amp; A：Remove HTML Tags from an NSString on the iPhone

Answer 3

我有一段时间遇到同样的问题，我只是想通知如果我从网页上提取数据让我们说PHP页面，那么该页面中不应该有任何HTML标记。所以结构如：

<html>
<body>
<?php

?>
</body>
</html>

会破坏你的结果。把它变成：

<?php

?>

为我工作。

Answer 4

现在已经有一段时间了，但打印数据更简单的方法是：

NSLog（@“％@”，[[NSString alloc] initWithData：data 编码：NSUTF8StringEncoding]）;

Answer 5

有一种方法，您可以通过邮寄请求解析jsondata

 -(void)callWebserviceList
 {
spinner.hidden=NO;

NSString *bodyData = @"code_request=monuments_list&asi_id=1";

NSMutableURLRequest *postRequest = [NSMutableURLRequest requestWithURL:[NSURL   URLWithString:@"http://asicircles.com/server_sync.php"]];

// Set the request's content type to application/x-www-form-urlencoded
[postRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];

// Designate the request a POST request and specify its body data
[postRequest setHTTPMethod:@"POST"];
[postRequest setHTTPBody:[NSData dataWithBytes:[bodyData UTF8String] length:strlen([bodyData UTF8String])]];

connection1 = [NSURLConnection connectionWithRequest：postRequest委托：self];

if(connection1 !=nil)
{
    ////NSLog(@"%@",postRequest);
}

}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {

if ([connection isEqual:connection1 ])
{
     [responseData setLength:0];

}else if ([connection isEqual:connection2 ])
{
     [responseData1 setLength:0];
}

} - （void）connection：（NSURLConnection *）connection didReceiveData：（NSData *）data {

    if ([connection isEqual:connection1 ])
  {
    [responseData appendData:data];

}else if ([connection isEqual:connection2 ])
{
     [responseData1 appendData:data];
}


//**check here for responseData & also data**

}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
NSLog(@"%@",[NSString stringWithFormat:@"Connection failed: %@", [error description]]);
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
if ([connection isEqual:connection1 ])
{
    spinner.hidden=YES;
    NSError *error;

    NSDictionary* json = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];

    NSMutableArray *arrdata=[json objectForKey:@"message"];
    NSLog(@"code is%@", json);

    for (int i=0; i< arrdata.count; i++)
    {
        [arrDetails addObject:[[arrdata objectAtIndex:i]objectForKey:@"details"]];
        [arrImageUrl addObject:[[arrdata objectAtIndex:i]objectForKey:@"image"]];
        [arrLat addObject:[[arrdata objectAtIndex:i]objectForKey:@"lat"]];
        [arrLongi addObject:[[arrdata objectAtIndex:i]objectForKey:@"longi"]];
        [arrName addObject:[[arrdata objectAtIndex:i]objectForKey:@"name"]];
        [arrLoc addObject:[[arrdata objectAtIndex:i]objectForKey:@"location"]];
        [arrID addObject:[[arrdata objectAtIndex:i]objectForKey:@"id"]];

        NSLog(@"code is%@",[[arrdata objectAtIndex:i]objectForKey:@"details"]);
        NSLog(@"code is%@",[arrImageUrl objectAtIndex:i]);

    }



    if (arrName.count > 0)
    {
        [self addscrollView];
    }



}else if ([connection isEqual:connection2 ])
{

}


}

Answer 6

您还可以在ios中按块查找json数据的网址

 #define kBgQueue dispatch_get_global_queue(
 DISPATCH_QUEUE_PRIORITY_DEFAULT, 0) //1
#define kLatestKivaLoansURL [NSURL URLWithString: 
 @"http://api.kivaws.org/v1/loans/search.json?status=fundraising"] //2

我们需要做的第一件事是从网上下载JSON数据。幸运的是，使用GCD，我们可以在一行代码中执行此操作！将以下内容添加到ViewController.m：

- (void)viewDidLoad
{
[super viewDidLoad];

dispatch_async(kBgQueue, ^{
    NSData* data = [NSData dataWithContentsOfURL: 
      kLatestKivaLoansURL];
    [self performSelectorOnMainThread:@selector(fetchedData:) 
      withObject:data waitUntilDone:YES];
});
}
- (void)fetchedData:(NSData *)responseData {
//parse out the json data
NSError* error;
NSDictionary* json = [NSJSONSerialization 
    JSONObjectWithData:responseData //1

    options:kNilOptions 
    error:&error];

NSArray* latestLoans = [json objectForKey:@"loans"]; //2

NSLog(@"loans: %@", latestLoans); //3
}

iOS JSON Parse无法正常工作（返回null字典）

6 个答案: