iOS開發中有可能用到的知識點大總結(不定期更新)

就算在牛逼的大神也不一定有好的記性,在開發中有時候一些小點就是想不起來。這里總結下最近遇到的,不定期更新--

1、 關閉隱式動畫

開發中有時候會遇到莫名其妙不希望出現的動畫,肯定是系統的隱式動畫再起作用,layer層屬性默認是帶動畫的 可以用下面的方式禁掉

CATransaction.begin()
CATransaction.setDisableActions(true) // 關閉動畫
//你的代碼  
CATransaction.commit()
2、文件存取

在開發中有時候要本地緩存一些文件文件只能放在document文件夾下才能存取
下面是獲取文件夾目錄方式

let paths = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)
let documentDirectory = paths[0]

后面加自己設定的目錄就行了

下面放下我寫的文件讀取的方法 傳入key folder等 自己摸索吧。

 //MARK: -從文件獲取用戶信息
    static func getUserFromDisk(key:String,folder:String)->AnyObject?{
        //反歸檔 獲取
        let fileManager = NSFileManager.defaultManager()
        if fileManager.fileExistsAtPath(folder){
            let mdata = NSMutableData(contentsOfFile:folder )
            let unArchiver = NSKeyedUnarchiver(forReadingWithData: mdata!)
            let u = unArchiver.decodeObjectForKey(key)
            return u
        }
        return nil
    }
    
    
    static func saveModelToFile(key:String,value:AnyObject?,folder:String){
        let data = NSMutableData()
        var keyArchiver:NSKeyedArchiver!
        keyArchiver =  NSKeyedArchiver(forWritingWithMutableData: data)
        
        keyArchiver.encodeObject(value, forKey: key)
        keyArchiver.finishEncoding() //歸檔完畢
        
        do {
            try data.writeToFile(folder, options: NSDataWritingOptions.DataWritingAtomic)
        }catch let err{
            print("err:\(err)")
        }
    }
3、http圖片或者網絡不能訪問

http開頭蘋果認為不是安全的連接,要手動配置下,在plist里加上如下代碼

<key>NSAppTransportSecurity</key>
    <dict>
        <key>NSAllowsArbitraryLoads</key>
        <true/>
    </dict>
4、判斷兩個矩形是否相交
  CGRectIntersection(<#T##r1: CGRect##CGRect#>, <#T##r2: CGRect##CGRect#>)
5、解決添加tap手勢后點擊cell無響應

實現UIGestureRecognizerDelegate協議下面的方法

   func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldReceiveTouch touch: UITouch) -> Bool {

        if  NSStringFromClass(touch.view!.classForCoder) == "UITableViewCellContentView"{
            return false
        }
        return true
    }
5、tableView自動布局高度自適應

至于怎么約束,不再這里討論

tableView.estimatedRowHeight = 50  //預估高度
tableView.rowHeight = UITableViewAutomaticDimension
6、讀取plist文件
    let plistPath = NSBundle.mainBundle().pathForResource("SampleData", ofType: "plist")
    if let plistPath=plistPath{
        let arr = NSArray(contentsOfFile: plistPath)        
        print(arr)
    }
7、tableView不顯示多余行,不顯示分割線,從xib中注冊
tableView.separatorStyle = UITableViewCellSeparatorStyle.None
tableView.tableFooterView = UIView(frame: CGRectZero)
tableView.registerNib(UINib(nibName: "homePageCell", bundle: NSBundle.mainBundle()), forCellReuseIdentifier: "cell")  //從nib 注冊cell
8、自定義導航欄的一些屬性
  //自定義一些導航欄的顏色
        UINavigationBar.appearance().barTintColor = UIColor(red: 231.0/255.0, green: 95.0/255.0, blue:
            53.0/255.0, alpha: 0.3)
        UINavigationBar.appearance().tintColor = UIColor.whiteColor()
        
        if let barFont = UIFont(name: "AvenirNextCondensed-DemiBold",
            size: 22.0) {
            UINavigationBar.appearance().titleTextAttributes =
            [NSForegroundColorAttributeName:UIColor.whiteColor(),
            NSFontAttributeName:barFont]
        }

self.navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: .Plain, target: nil, action: nil)  //返回按鈕位空
9 、自定義tabbar的一些屬性
 UIBarButtonItem.appearance().tintColor = UIColor(red: 235.0/255.0, green: 73.0/255.0, blue:
            27.0/255.0, alpha: 1.0)
 UIToolbar.appearance().barTintColor = UIColor(red: 237.0/255.0, green: 240.0/255.0, blue:
            243.0/255.0, alpha: 0.5)
10、UIImagePickerController 選擇圖片的簡單實用(單選)
 //如果相冊可用
  if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.PhotoLibrary){
            let imagePicker = UIImagePickerController()
            imagePicker.allowsEditing = false
            imagePicker.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
            
            self.presentViewController(imagePicker, animated: true, completion: nil)
}
11、擴展UIImage的兩個方法
extension UIImage{

    //圖像比例縮放
    func scaleImage(img:UIImage,scaleSize:CGFloat)->UIImage{
        UIGraphicsBeginImageContext(CGSizeMake(img.size.width * scaleSize, img.size.height * scaleSize))
        img.drawInRect(CGRectMake(0, 0, img.size.width * scaleSize, img.size.height * scaleSize))
        let scaledImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return scaledImage
    }
    
    
    //自定長寬
    func reSizeImage( toSize:CGSize)->UIImage{
        UIGraphicsBeginImageContext(CGSizeMake(toSize.width, toSize.height));
        self.drawInRect(CGRectMake(0, 0, toSize.width, toSize.height))
        let reSizeImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return reSizeImage;
    }
}
12、空數據顯示方案
import UIKit

extension UITableView{

    //MARK: -空table的解決方案
    func tableViewMsgWhenEmpty(message:String,rowCount:Int){
        if rowCount == 0{
            //沒有數據
            let messageLabel = UILabel()
            // Display a message when the table is empty
            messageLabel.text = message;
            messageLabel.textColor = MAIN_COLOR
            messageLabel.numberOfLines = 0
            messageLabel.textAlignment = NSTextAlignment.Center
            messageLabel.font = UIFont.systemFontOfSize(17)
            messageLabel.sizeToFit()
            self.backgroundView = messageLabel
            messageLabel.frame = CGRectMake(0, 0, self.frame.width, self.frame.height)

            messageLabel.sizeToFit()
            self.separatorStyle = UITableViewCellSeparatorStyle.None
        }else{
            //有數據
            self.backgroundView = nil
            self.separatorStyle = UITableViewCellSeparatorStyle.SingleLine
        }
    }
    
}
13、上傳照片的時候要先壓縮下,不然一個圖片幾M 上傳到服務器太浪費資源
let data = UIImageJPEGRepresentation(img,0.5)

第一個參數是UIImage對象 第二個是壓縮比率 ,應該不會失真

14、對象的序列化與反序列化
class Tag: NSObject,NSCoding {

    var id:NSNumber?
    var name:String?
    
    override init() {
        
    }
    
    //MARK: -序列化
    func encodeWithCoder(aCoder: NSCoder) {
        aCoder.encodeObject(self.name, forKey: "name")
        aCoder.encodeObject(self.id, forKey: "id")
    }
    
    //MARK: -反序列化
    required init?(coder aDecoder: NSCoder) {
        self.id = aDecoder.decodeObjectForKey("id") as? NSNumber
        self.name = aDecoder.decodeObjectForKey("name") as? String
    }
}
15、跳轉明細頁的時候隱藏tabbar
let followsVC = FollowsViewController()
followsVC.hidesBottomBarWhenPushed = true
self.navigationController?.pushViewController(followsVC, animated: true)
16、iOS8以上UITableCell左邊不留空,一點空都沒有哦
 cell.preservesSuperviewLayoutMargins = false
 cell.layoutMargins = UIEdgeInsetsZero
17、Segue相關的幾個方法
//用來判斷是否需要跳轉
 override func shouldPerformSegueWithIdentifier(identifier: String, sender: AnyObject?) -> Bool {
        if xxxxx == nil{
            return false
        }
        return true
    }
    
    //可以用代碼 直接控制跳轉
    override func performSegueWithIdentifier(identifier: String, sender: AnyObject?) {
       
    }
    //是點擊界面上的按鈕 根據你綁定的跳轉界面進行跳轉
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        
    }
18、http 請求需要在plist添加如下代碼塊
<key>NSAppTransportSecurity</key>
<dict>
    <key>NSAllowsArbitraryLoads</key>
    <true/>
</dict>
19、DM5加密
extension String{
    
    //MARK: -字符串替換
    func myreplace(oldStr:String,newStr:String)->String{
        return self.stringByReplacingOccurrencesOfString(oldStr, withString: newStr, options: NSStringCompareOptions.NumericSearch, range: nil)
    }
    
    //MARK: -MD5算法
    func md5() ->String!{
        let str = self.cStringUsingEncoding(NSUTF8StringEncoding)
        let strLen = CUnsignedInt(self.lengthOfBytesUsingEncoding(NSUTF8StringEncoding))
        let digestLen = Int(CC_MD5_DIGEST_LENGTH)
        let result = UnsafeMutablePointer<CUnsignedChar>.alloc(digestLen)
        CC_MD5(str!, strLen, result)
        let hash = NSMutableString()
        for i in 0 ..< digestLen {
            hash.appendFormat("%02x", result[i])
        }
        result.destroy()
        return String(format: hash as String)
    }
} 
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