Swift学习笔记二

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Project 1 & Project 2

  1. 从Cell(而不是整个Table View)跳转到Detail View
    在Storyboard里，用control 拖动建立IB时，需要在各自组件的Custom Class的Class添加关联，Cell选择相应的Cell
  2. Could not insert new outlet connection ……
    1. 关闭xcode.
    2. 进入~/Library/Developer/XCode/DerivedData目录，删除名字为 工程名+一连串字母的文件夹
  3. cp使用-R参数后可以复制文件或文件夹，不加-R参数只能复制文件

  4. NSFileManager的使用

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    let fm = NSFileManager.defaultManager()
    let path = NSBundle.mainBundle().resourcePath!
    let items = try! fm.contentsOfDirectoryAtPath(path)

    for item in items {
      if (item.hasPrefix("nssl")) {
          objects.append(item)
      }
    }

  5. In iOS, sizes are measured in “points”, not pixels.

  6. GameplayKit的使用，以及数组元素的随机排序，设置生成随机数的上限。

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    import GameplayKit
    countries = GKRandomSource.sharedRandom().arrayByShufflingObjectsInArray(countries) as! [String]
    correctAnswer = GKRandomSource.sharedRandom().nextIntWithUpperBound(3)

  7. 3个button共用一个sender，使用不同的tag来区分

  8. 设置button的宽度及颜色，UIColor位于上层，CGColor继承自UIColor

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    button.layer.borderWidth = 1
    button.layer.borderColor = UIColor.lightGrayColor().CGColor

  9. 弹窗提醒的代码

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    let ac = UIAlertController(title: title, message: "You score is \(score)", preferredStyle: .Alert)
    ac.addAction(UIAlertAction(title: "Continue", style: .Default, handler: askQuestion))
    presentViewController(ac, animated: true, completion: nil)

Project 3 Social Media

  1. import Social 引入社交包, 设置右上角的button

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    navigationItem.rightBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Action, target: self, action: "shareTapped")

  2. UIActivityViewController 分享功能，示例为调用Twitter

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    let vc = SLComposeViewController(forServiceType: SLServiceTypeTwitter)
    vc.setInitialText("Look at this amazing picture!")
    vc.addImage(detailImageView.image!)
    vc.addURL(NSURL(string: “http://www.123.com/"))
    presentViewController(vc, animated: true, completion: nil)

Project 4 Easy Browser

  1. 使用WebKit WebView

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    override func loadView() {
        webView = WKWebView()
        webView.navigationDelegate = self
        view = webView
    }

  2. 使用NSURL打开网址，允许返回

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    let url = NSURL(string: "https://m.baidu.com")!
    webView.loadRequest(NSURLRequest(URL: url))
    webView.allowsBackForwardNavigationGestures = true  打开为空白页
    func openPage(action: UIAlertAction!)

  3. 添加ToolBar,刷新键

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    let refresh = UIBarButtonItem(barButtonSystemItem: .Refresh, target: webView, action: "reload")
    toolbarItems = [spacer, refresh]
    navigationController?.toolbarHidden = false

  4. 将UIProgressView包裹进UIBarButtonItem

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    progressView = UIProgressView(progressViewStyle: .Default)
    progressView.sizeToFit()
    let progressButton = UIBarButtonItem(customView: progressView)

  5. KVO (Key-Value Observer)

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       webView.addObserver(self, forKeyPath: "estimatedProgress", options: .New, context: nil)
    	 override func observeValueForKeyPath(......) {
        ......
    }

  6. 阻止用户访问某些链接，使用rangeOfString方法

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      func webView(webView: WKWebView, decidePolicyForNavigationAction…) {
          let url = navigationAction.request.URL

          if let host = url!.host {
              for website in websites {
                  if host.rangeOfString(website) != nil {
                      decisionHandler(.Allow)
                      return
                  }
              }
          }
          decisionHandler(.Cancel)
    }

Project 5 Word Scramble

  1. 寻找文本路径、载入文本、处理文本

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     if let startWordsPath = NSBundle.mainBundle().pathForResource("start", ofType: "txt") {
          if let startWords = try? String(contentsOfFile: startWordsPath, usedEncoding: nil) 	{
                 allWords = startWords.componentsSeparatedByString("\n")
          }

          } else {
             allWords = [“silkworm"]      
    }

  2. 清空、重载TableView数据

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    objects.removeAll(keepCapacity: true)
    tableView.reloadData()

  3. 无主引用 (an unowned reference is one you’re certifying cannot be nil and so doesn’t need to be unwrapped.)

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    let ac = UIAlertController(title: "Enter answer", message: nil, preferredStyle: .Alert)
    ac.addTextFieldWithConfigurationHandler(nil)
    let submitAction = UIAlertAction(title: "Submit", style: .Default) { [unowned self, ac](action: UIAlertAction!) in
        let answer = ac.textFields![0]
        self.submitAnswer(answer.text!)
    }
    ac.addAction(submitAction)
    presentViewController(ac, animated: true, completion: nil)

  4. 仅插入指定的行到table view，而不是整个reload

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    objects.insert(lowerAnswer, atIndex: 0)
    let indexPath = NSIndexPath(forRow: 0, inSection: 0)
    tableView.insertRowsAtIndexPaths([indexPath], withRowAnimation: .Automatic)
    tempWord.removeAtIndex() 移除并且返回该元素

  5. 检查单词是否是一个正确的单词，使用NSMakeRange

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    func wordIsReal(word: String) -> Bool {
        let checker = UITextChecker()
        let range = NSMakeRange(0, word.characters.count)
        let misspelledRange = checker.rangeOfMisspelledWordInString(word, range: range, startingAt: 0, wrap: false, language: "en")

        return misspelledRange.location == NSNotFound
    }

  6. !objects.contains(word) 报错，待修改

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    Cannot convert value of type 'String' to expected argument type '@noescape (AnyObject) throws -> Bool’

Project 6 Auto Layout

  1. 隐藏状态栏

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    override func prefersStatusBarHidden() -> Bool {
        return true
    }

  2. 关闭自动布局 label.translatesAutoresizingMaskIntoConstraints = false

  3. Auto Layout Visual Format Language (VFL)

    1. H表示水平方向 The pipe symbol | means “the edge of the view.”

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      for label in viewsDictionary.keys {
           view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[\(label)]|", options: [], metrics: ["labelHeight": 88], views: viewsDictionary))
      }

    2. V表示竖直方向 -symbol, which means “space”. It’s 10 points by default

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      "V:|[label1(labelHeight@999)]-[label2(label1)]-[label3(label1)]-[label4(label1)]-[label5(label1)]-(>=10)-|"

  4. TL;DR (Too Long, Didn’t Read) 太长不看