具有自定义数据数组的函数

Question

我有以下函数调用：

@IBAction func submitCourse(sender: AnyObject) {
    // print("Enter")
        getTime( (courseName.text!), courseCode: (codeName.text!))
        print(classes[0].end);
        //print("ASODASODJASDJASASDASDD \(string1)")
}

以及自定义数据类：

class ClassSchedule {
var course: String?
var code: String?
var section: String?
var start: String?
var end: String?

init(course: String, code: String, section: String, start: String, end: String)
{
    self.course = course
    self.code = code
    self.section = section
    self.start = start
    self.end = end

}

}

并请求JSON对象，将其解析为classSchedule的数组：

 // Read the JSON
    do {
        let data: NSData? = NSData(contentsOfURL: url)
        if let jsonResult: NSDictionary = try NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as? NSDictionary
        {
            //////ARRAY///////
            let dataArray = jsonResult["data"] as! NSArray
            //////
            let arrayLength = dataArray.count
            var count = 0


            print("TOTAL OF CLASSES: \(arrayLength)");

            for item in dataArray
            {              
                 classes.append(ClassSchedule(course: "TEMP", code: "TEMP", section: "TEMP", start:"TEMP", end:"TEMP") )

                classes[count].course = item["subject"] as! String
                classes[count].code = item["catalog_number"] as! String
                classes[count].section = item["section"] as! String
                print("Subject: \(classes[count].course!) \(classes[count].code!)");
                print("Section: \(classes[count].section!)");
              // print("Section: \(section_numb)");

                let subjectArray = item["classes"] as! NSArray
                for item2 in subjectArray{

                    let dateDictionary = item2["date"] as! NSDictionary
                    //let startTime = dateDictionary["start_time"]!
                    //self.performSelectorOnMainThread("updateIPLabel:", withObject: startTime, waitUntilDone: false)
                    //let endTime = dateDictionary["end_time"]!
                    classes[count].start = dateDictionary["start_time"] as! String
                    classes[count].end = dateDictionary["end_time"] as! String
                    string1 = classes[count].start!
                    print("START TIME: \(classes[count].start!)");
                    print("End Time: \( classes[count].end!)");
                    print("")
                   count += 1
                    print(count)

                }

            }
            //let subject = dataArray["subject"]
        }

    } catch {
        print("bad things happened")
    }

    print("ASDIAWDWD: \(classes[0].section)")
   // print("ASDIAWDWASDASDD: \(classes[1].section)")
    }).resume()

函数中的那些打印语句可以正常工作并打印想要的数据。 我无法将 ClassSchedule 的填充数组返回到 ViewController.swift。

我尝试将数组声明为全局变量，但它仍然在print(classes[0].end); 出现错误，提示数组索引超出范围。

感觉是JSON的异步请求导致的，但不知道怎么解决。

Answer 1

是的。那是因为它是一个异步调用。您必须在 API 调用成功中保留一个本地数组，并且在所有处理之后，您必须有一个回调将数据发送回调用者。即，在进行 API 调用时，您必须有一个块作为参数。

更新

func yourAPICall(addNecessaryParameters, failure: NSError -> (), completion: NSArray -> ()) {
    // API call and parsing goes here

    var returnArray = [AnyObject]()
    if let _ = error {
        failure(error!)
    }
    else {
        completion(returnArray)
    }
}