小编Pau*_* S.的帖子

我有一个返回字典的通知,就像在objective-c中一样,但我没有得到我期望的结果.

这是发布通知的方法.它实际上返回了日期选择器的结果(日期).

@IBAction func dateOfBirthAction(sender: AnyObject) {

    println("Date: \(dateOfBirthPicker.date)")

    var selectedDateDictionary = [dateOfBirthPicker.date, "dateOfBirth"]

    NSNotificationCenter.defaultCenter().postNotificationName("dateOfBirth", object: nil, userInfo: [NSObject():selectedDateDictionary])

}

这是通知观察员:

override func viewDidLoad() {
    super.viewDidLoad()

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "dateOfBirth:", name: "dateOfBirth", object: nil)

}

func dateOfBirth(notification: NSNotification) {

    println("userInfo: \(notification.userInfo)")

    let returnedDateOfBirth = notification.userInfo!["dateOfBirth"] as NSString
    println("returnedDateOfBirth: \(returnedDateOfBirth)")

    playerInformationDateOfBirthLabel.text  = returnedDateOfBirth
}

我在线路上收到以下错误 let returnedDateOfBirth:String = notification.userInfo["dateOfBirth"]

userInfo: Optional([<NSObject: 0x7fb15a44a880>: <_TtCSs23_ContiguousArrayStorage00007FB15A4D4380 0x7fb15a4206a0>(
2014-09-18 12:07:07 +0000,
dateOfBirth
)
])
fatal error: unexpectedly found nil while unwrapping an Optional value

完整的解决方案

@IBAction …

从上图我有UICollectionView4个自定义单元格.任何时候屏幕上都可以有2或3个单元格.如何判断屏幕上"单元格1"或"单元格2"何时为100%？

都

collectionView.visibleCells
collectionView.indexPathsForVisibleItems

返回数组并不会告诉你屏幕上是否有100%的单元格.

在图像的情况下,将显示以下内容 didSelectItemAt

collectionView.visibleCells

[<Shot_On_Goal.MainCollectionViewCell: 0x101f525c0; baseClass = UICollectionViewCell; frame = (190 7.66667; 454 350); clipsToBounds = YES; opaque = NO; layer = <CALayer: 0x1c0237300>>, <Shot_On_Goal.HeaderCollectionViewCell: 0x101f4d580; baseClass = UICollectionViewCell; frame = (10 0; 170 365); clipsToBounds = YES; opaque = NO; layer = <CALayer: 0x1c0236800>>, <Shot_On_Goal.TheirHockeyNetCollectionViewCell: 0x101f55520; baseClass = UICollectionViewCell; frame = (654 7.66667; 454 350); clipsToBounds = YES; opaque = NO; layer = <CALayer: 0x1c0238fe0>>]

collectionView.indexPathsForVisibleItems

[[0, 1], [0, 0], [0, 2]] 

我是PowerShell的第一次程序员.在Windows Server 2012上运行.

我正在尝试获取故障转移群集上所有VM的列表并正在使用此代码:

$clusterNodes = Get-ClusterNode | select Name 
ForEach($item in $clusterNodes)
{Get-VM -ComputerName $item}

这会返回一堆错误

但是,这完全没问题

$hosts = "server1", "server2", "server3", "server4"
ForEach($item in $hosts)
{Get-VM -ComputerName $item}

它是否失败,因为Get-ClusterNode | select Name返回以下内容？

Name
----
server1
server2
server3
server4

标题和下划线？

使用这个简单的代码,我假设"Hello World!"自动收缩会起作用,bannerLabel.adjustsFontSizeToFitWidth但文本的末尾会被剪切,...如何让它正常工作？

import UIKit

class ViewController: UIViewController, UIGestureRecognizerDelegate {

    @IBOutlet weak var bannerLabel: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()

        bannerLabel.adjustsFontSizeToFitWidth = true
        bannerLabel.numberOfLines = 1
        bannerLabel.text = "Hello World!"
        bannerLabel.font = UIFont(name: bannerLabel.font.fontName, size: 150)!

    }

我将如何删除如下所示的字符串周围的 {}？{636D9115-E54E-4673-B992-B51A8F8DDC8B}我只想返回以下内容：636D9115-E54E-4673-B992-B51A8F8DDC8B

请考虑以下内容,如何删除前导零,并保留3个小数位？savePercentageDecimals返回0.923,我想只需.923

    //Figure out Save Percentage
    let savePercentage = 12.0 / (1.0 + 12.0)
    let savePercentageDecimals = String(format: "%.3f",savePercentage)

提前致谢!

我不想问这个，因为我觉得我错过了一些非常简单的东西，但我一直在这个问题上纠结太久了。

当用户点击我的单元格时，我collectionView存储 indexPath.row 和一个名为timeOnIce的数组中调用的值tappedArray

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {

     let cell = collectionView.cellForItem(at: indexPath) as! BenchCollectionViewCell

     if cell.cellBackgroundImageView.image == UIImage(named: "collectionviewcell_60x60_white") {

        cell.cellBackgroundImageView.image = UIImage(named: "collectionviewcell_60x60_blue")

        let currentPlayerSelected = ["indexPath": indexPath.row, "timeOnIce": 0]
        tappedArray.append(currentPlayerSelected)

     } else {

       cell.cellBackgroundImageView.image = UIImage(named: "collectionviewcell_60x60_white")

       tappedArray = tappedArray.filter { $0["indexPath"] != indexPath.row }

     }
}

按下启动计时器的按钮

func startTimer()  {

    //start the timer
    timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(updateCounters), userInfo: nil, repeats: true)

}  //startTimer …

我在使用swift显示UIPopover时遇到了一些麻烦.注释掉的代码在Objective-C中工作正常,但使用Swift不起作用.当我点击我的视图控制器中的+时,我在调试器中得到了"click",但是没有弹出窗口.

class PlayerInformationTableViewController: UITableViewController, NSFetchedResultsControllerDelegate, UIPopoverControllerDelegate {

    @IBOutlet weak var addBarButtonItem: UIBarButtonItem!

    var playerInformationViewController = PlayerInformationViewController()
    var popover:UIPopoverController?    = nil

    override func viewDidLoad() {
        super.viewDidLoad()

        /*

        //setup the popover
        _cuesPopoverViewController          = [self.storyboard instantiateViewControllerWithIdentifier:@"CuesPopoverViewController"];
        self.cuesPopover                    = [[UIPopoverController alloc] initWithContentViewController:_cuesPopoverViewController];
        self.cuesPopover.popoverContentSize = CGSizeMake(540, 300);
        self.cuesPopover.delegate           = self;

        */

    playerInformationViewController.storyboard?.instantiateViewControllerWithIdentifier("PlayerInformationViewController")
    popover?.contentViewController = playerInformationViewController
    popover?.popoverContentSize = CGSizeMake(300, 300)
    popover?.delegate = self


        // Uncomment the following line to preserve selection between presentations
        // self.clearsSelectionOnViewWillAppear = false

        // Uncomment the following line to display an Edit …

我使用Xcode和Objective-C对iOS编程相对较新.

我需要能够将歌曲的长度(例如3:31)转换为表示秒的整数.所以3:31(mm:ss)将是211秒,然后从211回到3:31.

任何帮助我开始的帮助将不胜感激.

使用Swift.如何获取String并将每个字符分成数组？

var someString = "123"
var someArray = []

someArray[0] = "1"
someArray[1] = "2"
someArray[2] = "3"