我知道这已经得到了回答，但是这个错误的答案还没有帮助。
我正在尝试从服务器获取数据并将其放在表视图中，但它不会显示。我有这段代码来确定是否接收数据：
func URLSession(session: NSURLSession, task: NSURLSessionTask, didCompleteWithError error: NSError?) {
if error != nil {
print("Failed to download data")
}else {
print("Data downloaded")
self.parseJSON()
}
}
但它不起作用。控制台的输出为：
Data downloaded
Error Domain=NSCocoaErrorDomain Code=3840 "Invalid value around character 0." UserInfo={NSDebugDescription=Invalid value around character 0.}
那么为什么数据说它已下载，但后来我收到错误？我的网址绝对正确。
这是我的解析JSON函数：
func parseJSON() {
var jsonResult: NSMutableArray = NSMutableArray()
do{
jsonResult = try NSJSONSerialization.JSONObjectWithData(self.data, options:NSJSONReadingOptions.AllowFragments) as! NSMutableArray
} catch let error as NSError {
print(error)
}
var jsonElement: NSDictionary = NSDictionary()
let locations: NSMutableArray = NSMutableArray()
for(var i = 0; i < jsonResult.count; i++)
{
jsonElement = jsonResult[i] as! NSDictionary
let location = LocationModel()
//the following insures none of the JsonElement values are nil through optional binding
if let accented = jsonElement["Accented"] as? String,
let unaccented = jsonElement["Unaccented"] as? String
{
location.accented = accented
location.unaccented = unaccented
}
locations.addObject(location)
}
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.delegate.itemsDownloaded(locations)
})
}
以下是来自服务器的数据：
<html>n<head>n<meta http-equiv="content-type" content="text/html; charset=utf-8">n</head>n<body>n[{"id":"1","accented":"mē","unaccented":"me"},{"id":"2","accented":"quid","unaccented":"quid"},{"id":"3","accented":"nihil","unaccented":"nihil"},{"id":"4","accented":"nōn","unaccented":"non"},{"id":"5","accented":"saepe","unaccented":"saepe"},{"id":"6","accented":"sī","unaccented":"si"},{"id":"7","accented":"amō, amāre, amāvī, amātum","unaccented":"amo"},{"id":"8","accented":"amābō tē","unaccented":"amabo te"},{"id":"9","accented":"cōgitō, cōgitāre, cōgitāvī, cōgitātum","unaccented":"cogito"},{"id":"10","accented":"dēbeō, dēbēre, dēbuī, dēbitum","unaccented":"debeo"},{"id":"11","accented":"dō, dare, dedī, datum","unaccented":"do"},{"id":"12","accented":"errō, errāre, errāvī, errātum","unaccented":"erro"},{"id":"13","accented":"laudō, laudāre, laudāvī, laudātum","unaccented":"laudo"},{"id":"14","accented":"moneō, monēre, monuī, monitum","unaccented":"moneo"},{"id":"15","accented":"salveō, salvēre","unaccented":"salveo"},{"id":"16","accented":"salvē, salvēte","unaccented":"salve"},{"id":"17","accented":"servō, servāre, servāvī, servātum","unaccented":"servo"},{"id":"18","accented":"cōnservō, cōnservāre, cōnservāvī, cōnservātum","unaccented":"conservo"},{"id":"19","accented":"terreō, terrēre, terruī, territum","unaccented":"terreo"},{"id":"20","accented":"valeō, valēre, valuī, valitūrum","unaccented":"valeo"},{"id":"21","accented":"valē, valēte","unaccented":"vale"},{"id":"22","accented":"videō, vidēre, vīdī, vīsum","unaccented":"video"},{"id":"23","accented":"vocō, vocāre, vocāvī, vocātum","unaccented":"voco"}]</body>n</html>
问题是来自服务器的响应不是 JSON。这是一个 HTML 响应，其<BODY>是 JSON。您必须从响应正文中删除这些 HTML 标记。
在聊天中，我们发现您的 PHP 目前显示：
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
</head>
<body>
<?php
require 'database_data.php';
$dbc = mysqli_connect($site, $username, $password,$db) OR die('ERROR! Could not connect to the database.');
mysqli_set_charset($dbc, 'utf8');
$query = 'SELECT * FROM database';
if ($result = mysqli_query($dbc, $query))
{
// If so, then create a results array and a temporary one
// to hold the data
$resultArray = array();
$tempArray = array();
// Loop through each row in the result set
while($row = $result->fetch_object())
{
// Add each row into our results array
$tempArray = $row;
array_push($resultArray, $tempArray);
}
// Finally, encode the array to JSON and output the results
echo json_encode($resultArray, JSON_UNESCAPED_UNICODE);
}
?>
</body>
</html>
您应该从文件中删除 HTML 标记。它应该只是：
<?php
require 'database_data.php';
$dbc = mysqli_connect($site, $username, $password,$db) OR die('ERROR! Could not connect to the database.');
mysqli_set_charset($dbc, 'utf8');
$query = 'SELECT * FROM database';
if ($result = mysqli_query($dbc, $query))
{
// If so, then create a results array and a temporary one
// to hold the data
$resultArray = array();
$tempArray = array();
// Loop through each row in the result set
while($row = $result->fetch_object())
{
// Add each row into our results array
$tempArray = $row;
array_push($resultArray, $tempArray);
}
mysqli_close($dbc);
// Finally, encode the array to JSON and output the results
header("Content-Type", "application/json");
echo json_encode($resultArray, JSON_UNESCAPED_UNICODE);
}
?>
另请注意，我添加了Content-Type标头，以便响应正确格式化为 JSON。
就个人而言，我倾向于将失败更改为也输出 JSON，而不仅仅是调用die（以便应用程序可以优雅地检测错误），但这并不那么重要。