相关疑难解决方法(0)

有两个UIBarButtonItem想要将它作为一个UIBarButtonItem并在它们之间切换

UIBarButtonItem *systemItem1 = [[UIBarButtonItem alloc]
                               initWithBarButtonSystemItem:UIBarButtonSystemItemPlay 
                               target:self 
                               action:@selector(playaudio:)];

systemItem1.style = UIBarButtonItemStyleBordered;

UIBarButtonItem *systemItem2 = [[UIBarButtonItem alloc] 
                               initWithBarButtonSystemItem:UIBarButtonSystemItemPause
                               target:self
                               action:@selector(pause:)];

systemItem2.style = UIBarButtonItemStyleBordered;


// flex item used to put space in between buttons

UIBarButtonItem *flexItem = [[UIBarButtonItem alloc] 
                             initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace
                             target:nil
                             action:nil];

//Add buttons to the array

NSArray *toolbarItems = [NSArray arrayWithObjects: settingsButton, flexItem, systemItem, flexItem, systemItem1,flexItem, systemItem2, flexItem, systemItem3, flexItem, modalBarButtonItem, nil];

 [toolbar setItems:toolbarItems];

[settingsButton release];
[systemItem  release];
[systemItem1 release];
[systemItem2 release];
[systemItem3 release];
[modalBarButtonItem release];
[flexItem release];

-(void) playaudio: …

我需要将播放按钮更改为暂停按钮,反之亦然.我还是新手,所以我不知道如何识别.swift文件中的按钮或如何在文件中以编程方式更改图标.swift.

import UIKit
import AVFoundation

class ViewController: UIViewController {

    var player = AVAudioPlayer()

    var toggleState = 1

    @IBAction func playPauseButton(sender: AnyObject) {
        if toggleState == 1 {
            player.play()
            toggleState = 2
        } else {
            player.pause()
            toggleState = 1
        }
    }

    @IBAction func stopButton(sender: AnyObject) {
        player.stop()
        player.currentTime = 0 
    }

    @IBAction func sliderChanged(sender: AnyObject) {
        player.volume = sliderValue.value
    }

    @IBOutlet weak var sliderValue: UISlider!

    override func viewDidLoad() {
        super.viewDidLoad()

        var audioPath = NSBundle.mainBundle().pathForResource("StarWars", ofType: "mp3")!
        var …