Question

我的Swift应用程序中有一个函数，它以hh：mm格式比较时间。它有一个存储时间的字典。当我尝试打印索引["seventh"]时，它返回nil。所有其他索引都有效。这是我的功能：

func timeShading() {
         //instance of time
    let calendar = NSCalendar.currentCalendar()
    let components = calendar.components([.Hour, .Minute], fromDate:NSDate())
         //set hour
    var hour = Int()
    hour = components.hour
         //set minute
    var minute = Int()
    minute = components.minute

    let dateFormatter = NSDateFormatter()
    dateFormatter.dateFormat = "hh:mm"

//      let theTime = NSDate().timeIntervalSince1970
    let theTime = dateFormatter.dateFromString("13:50")?.timeIntervalSince1970

    let classEpochTimes = [
        "first": [dateFormatter.dateFromString("08:20")?.timeIntervalSince1970, dateFormatter.dateFromString("09:04")?.timeIntervalSince1970],
        "second": [dateFormatter.dateFromString("09:05")?.timeIntervalSince1970, dateFormatter.dateFromString("09:49")?.timeIntervalSince1970],
        "third": [dateFormatter.dateFromString("10:10")?.timeIntervalSince1970, dateFormatter.dateFromString("10:54")?.timeIntervalSince1970],
        "fourth": [dateFormatter.dateFromString("10:55")?.timeIntervalSince1970, dateFormatter.dateFromString("11:39")?.timeIntervalSince1970],
        "fifth": [dateFormatter.dateFromString("11:40")?.timeIntervalSince1970, dateFormatter.dateFromString("12:19")?.timeIntervalSince1970],
        "sixth": [dateFormatter.dateFromString("12:20")?.timeIntervalSince1970, dateFormatter.dateFromString("12:59")?.timeIntervalSince1970],
        "seventh": [dateFormatter.dateFromString("13:40")?.timeIntervalSince1970, dateFormatter.dateFromString("15:00")?.timeIntervalSince1970],

        "break": [dateFormatter.dateFromString("09:50")?.timeIntervalSince1970, dateFormatter.dateFromString("10:09")?.timeIntervalSince1970],
        "lunch": [dateFormatter.dateFromString("13:00")?.timeIntervalSince1970, dateFormatter.dateFromString("13:39")?.timeIntervalSince1970]
    ]

//        If First Period
    if(theTime > classEpochTimes["first"]![0] && theTime < classEpochTimes["first"]![1]){
        firstPeriod.font = UIFont.boldSystemFontOfSize(30.0)
    }
//        If Second Period
    if(theTime > classEpochTimes["second"]![0] && theTime < classEpochTimes["second"]![1]){
        secondPeriod.font = UIFont.boldSystemFontOfSize(30.0)
    }
//        If Third Period
    if(theTime > classEpochTimes["third"]![0] && theTime < classEpochTimes["third"]![1]){
        thirdPeriod.font = UIFont.boldSystemFontOfSize(30.0)
    }
//        If Fourth Period
    if(theTime > classEpochTimes["fourth"]![0] && theTime < classEpochTimes["fourth"]![1]){
        fourthPeriod.font = UIFont.boldSystemFontOfSize(30.0)
    }
//        If Fifth Period
    if(theTime > classEpochTimes["fifth"]![0] && theTime < classEpochTimes["fifth"]![1]){
        fifthPeriod.font = UIFont.boldSystemFontOfSize(30.0)
    }
//        If Sixth Period
    if(theTime > classEpochTimes["sixth"]![0] && theTime < classEpochTimes["sixth"]![1]){
        sixthPeriod.font = UIFont.boldSystemFontOfSize(30.0)
    }
//        If Seventh Period
    if(theTime > classEpochTimes["seventh"]![0] && theTime < classEpochTimes["seventh"]![1]){
        seventhPeriod.font = UIFont.boldSystemFontOfSize(30.0)
    }

    print(theTime)
    print(classEpochTimes["seventh"]![0])
    print(classEpochTimes["seventh"]![1])
}

为什么它会返回nil？

Answer 1

您使用的格式错误。变化：

android.os.NetworkOnMainThreadException
    at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1155)
    at java.net.InetAddress.lookupHostByName(InetAddress.java:418)
    at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
    at java.net.InetAddress.getAllByName(InetAddress.java:215)
    at java.net.Socket.tryAllAddresses(Socket.java:109)
    at java.net.Socket.<init>(Socket.java:178)
    at java.net.Socket.<init>(Socket.java:150)
    at net.sourceforge.jtds.jdbc.SharedSocket.<init>(SharedSocket.java:259)
    at net.sourceforge.jtds.jdbc.ConnectionJDBC2.<init>(ConnectionJDBC2.java:311)
    at net.sourceforge.jtds.jdbc.Driver.connect(Driver.java:187)
    at java.sql.DriverManager.getConnection(DriverManager.java:179)
    at java.sql.DriverManager.getConnection(DriverManager.java:144)
    at uk.co.matprichardson.omgandroid.MainActivity.onClick(MainActivity.java:114)
    at android.view.View.performClick(View.java:4785)
    at android.view.View$PerformClick.run(View.java:19869)
    at android.os.Handler.handleCallback(Handler.java:739)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:155)
    at android.app.ActivityThread.main(ActivityThread.java:5721)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1029)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:824)

为：

dateFormatter.dateFormat = "hh:mm"

dateFormatter.dateFormat = "HH:mm"是12小时的时间。 hh是24小时。

调用时，NSDictionary的索引返回nil

1 个答案: