我试图写在斯威夫特完成处理功能,这是我在斯威夫特代码名为NBObjectiOS的斯威夫特3 CompletionHandler不工作
typealias CompletionHandler = (_ success: Bool, _ data: [String:Any]) -> Void
// FIND OBJECTS IN BACKGROUND
func findObjectInBackground(completionHandler: CompletionHandler) {
let tbNameStr = "table=" + theTableName
var rStr = ""
var theData = [String:Any]()
for i in 0..<columns.count {
rStr += "&c" + "\(i)" + "=" + columns[i] +
"&r" + "\(i)" + "=" + records[i]
}
recordString = tbNameStr + rStr
print("RECORD STRING: \(recordString)")
let requestURL = URL(string: PATH_TO_API_FOLDER + "queryWhereKeyContains.php?" + recordString)
//create the session object
let session = URLSession.shared
//now create the URLRequest object using the url object
let request = URLRequest(url: requestURL!)
//create dataTask using the session object to send data to the server
let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in
//exiting if there is some error
if error != nil {
print("Error is: \(error!.localizedDescription)")
return
} else {
}
do {
if let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? [String: Any] {
theData = json
print("JSON: \(json)")
}
} catch let error { print("ERROR IN PARSING JSON: \(error.localizedDescription)") }
})
task.resume()
let flag = true
completionHandler(flag, theData)
}
我调用该函数在我ViewController.swift,像类这样的:
let query = NJObject(tableName: HOTEL_TABLE_NAME)
query.whereKeyContains(columnName: HOTEL_NAME, record: "Hotel")
query.findObjectInBackground { (succ, objects) in
print("OBJECTS: \(objects)")
print("SUCCESS: \(succ)")
}
所以,在Xcode的控制台,我正确地让我的JSON数据,但在打印完成处理,data
(打印为对象)时是空的。
OBJECTS: [:]
SUCCESS: true
JSON: ["objects": <__NSArrayM 0x17004b4c0>(
{
address = "<null>";
createdAt = "2017-08-12 23:08:48";
description = "lorem ipsec dolor sit";
email = "<null>";
},
{
address = "<null>";
createdAt = "2017-08-14 06:19:10";
description = "lorem ipsec dolor sit";
email = "<null>";
})
]
有一两件事我注意到的是,控制台将首先打印对象作为空[:]和成功日志,那么JSON数据。
所以我肯定我的findObjectInBackground()
函数有问题,我只是不知道问题出在哪里。
任何帮助将不胜感激!
你是什么意思“它不能正确打印对象”?如果你的意思是'NSArray'部分,那是因为你的字典类型是'[String:Any]',并且当你解析JSON对象时,你不会向下转换为任何显式类型。 –
是的,我的意思是对象:[:]部分,所以我应该在ViewController.swift调用的函数中做什么? – cubycode
所以问题不在于打印,而是完成处理程序为空。看看我的答案。 –