swift 开发过程中的一些小总结

1. 计算字符串放进label中的高度

let size = CGSize (width: WIDTH - 20 , height: 0 )

let dic = NSDictionary (object: UIFont . systemFont (ofSize: 14 ), forKey: NSFontAttributeName as NSCopying )

let strSize = videoBody. summary ?. boundingRect (with: size, options: . usesLineFragmentOrigin , attributes: dic as ? [ String : Any ], context: nil ). size

self . label . frame = CGRect (x: 0 ,y: 0 ,width: WIDTH-20 ,height: strSize?. height !)

2.一些系统通知

打断时通知

NotificationCenter . default . addObserver ( self , selector: #selector ( onAudioSessionEvent ), name: NSNotification . Name . AVAudioSessionInterruption , object: nil )

2.进入后台的通知

NotificationCenter . default . addObserver ( self , selector: #selector ( onAppDidEnterBackGround ), name: NSNotification . Name . UIApplicationDidEnterBackground , object: nil )

3.将要进入前台的通知

NotificationCenter . default . addObserver ( self , selector: #selector ( onAppWillEnterForeground ), name: NSNotification . Name . UIApplicationWillEnterForeground , object: nil )

APP活跃状态的通知

NotificationCenter . default . addObserver ( self , selector: #selector ( onAppDidBecomeActive ), name: NSNotification . Name . UIApplicationDidBecomeActive , object: nil )

屏幕发生旋转的通知

NotificationCenter . default . addObserver ( self , selector: #selector ( statusBarOrientationChanged ), name: NSNotification . Name . UIApplicationDidChangeStatusBarOrientation , object: nil )

3.GCD多线程

  DispatchQueue.global().async {
               //耗时操作

               DispatchQueue.main.async {
                   //通知ui刷新

                }

            }

4.求余运算

 
  let  
  value1 = 5.5

 
   let  
   value2 = 2.2

 
  let  
  result = value1.truncatingRemainder(dividingBy: value2)

5.字符串format拼接

url:String(format:"%@/activity/listActivitys?start=%ld&limit=%ld",arguments[BASEADDRESS,withStart,withLimit])

6.判断数组是否有某元素 contains where

判断self.titleBodyArr数组中是否有id == 11的body

let has =self.titleBodyArr.contains(where: { (bo:FLGPindaoBody) ->Boolin

bo.id == 11

})

if has ==false{

self.dataArr.append(body)

}

7.md5 加密

创建文件

加入代码

import Foundation

extension String {
    var md5 : String {
        let str = self . cString (using: String . Encoding . utf8 )
        let strLen = CC_LONG ( self . lengthOfBytes (using: String . Encoding . utf8 ))
        let digestLen = Int ( CC_MD5_DIGEST_LENGTH )
        let result = UnsafeMutablePointer < CUnsignedChar >. allocate (capacity: digestLen)

        CC_MD5 (str!, strLen, result)

        let hash = NSMutableString ()
        for i in 0 ..< digestLen {
            hash. appendFormat ( "%02x" , result[i])
        }
        result. deinitialize ()

        return String (format: hash as String )
    }
}

在桥接文件中引头文件

#import <CommonCrypto/CommonDigest.h>

调用方法： let passStr = pwd.md5

8. 图片大小适应 UIimage

1. UIimageview 按图片最短边完整填充不变形

bigImageView?.contentScaleFactor =UIScreen.main.scale

bigImageView?.contentMode =UIViewContentMode.scaleAspectFill

bigImageView?.autoresizingMask =UIViewAutoresizing.flexibleHeight

bigImageView?.clipsToBounds =true

2.图片完全显示不变形

bigImageView?.contentScaleFactor = UIScreen.main.scale

bigImageView?.contentMode = UIViewContentMode.scaleAspectFit

bigImageView ?. clipsToBounds = true

swift 开发过程中的一些小总结

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