在NavigationItem中, 想要實現 Bar Button Item.System item的切換, 來達成開始搜尋藍芽與停止搜尋按鈕的轉換.
Step 1: Add Bar Button Item
先在Navigation Item中, 新增Bar Button Item且System item設定為Search
Step 2: 建立與程式的連結
Step 3: 撰寫切換按鈕圖案的程式碼
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| private func changeToStopButton() {
let stopScanningButton = UIBarButtonItem( barButtonSystemItem: UIBarButtonSystemItem.Stop, target: self, action: #selector(ViewController.stopScan));
self.navigationItem.rightBarButtonItem = stopScanningButton;
}
private func changeToScanButton() {
let scanButton = UIBarButtonItem( barButtonSystemItem: UIBarButtonSystemItem.Search, target: self, action: #selector(ViewController.startScan));
self.navigationItem.rightBarButtonItem = scanButton;
}
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Source Code
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| import UIKit
class ViewController: UIViewController {
var mBtManager : BtManager!;
override func viewDidLoad() {
super.viewDidLoad()
mBtManager = BtManager();
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
@IBAction func prepareScan(sender: AnyObject) {
startScan();
}
func startScan() {
mBtManager.startToScan();
changeToStopButton();
}
func stopScan() {
mBtManager.stopScanning();
changeToScanButton();
}
private func changeToStopButton() {
let stopScanningButton = UIBarButtonItem( barButtonSystemItem: UIBarButtonSystemItem.Stop, target: self, action: #selector(ViewController.stopScan));
self.navigationItem.rightBarButtonItem = stopScanningButton;
}
private func changeToScanButton() {
let scanButton = UIBarButtonItem( barButtonSystemItem: UIBarButtonSystemItem.Search, target: self, action: #selector(ViewController.startScan));
self.navigationItem.rightBarButtonItem = scanButton;
}
}
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