常用代码片段备忘

发表于 2015-08-03   |   分类于 iOS ， 备忘   |  

记录一些实用的代码片段

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常用代码片段备忘

Xcode

读取资源文件

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- (NSString *)sampleMarkdown
{
    NSString *samplePath = [[NSBundle mainBundle] pathForResource:@"sample" ofType:@"markdown"];
    
    NSError *error = nil;
    NSString *sample = [NSString stringWithContentsOfFile:samplePath encoding:NSUTF8StringEncoding error:&error];
    
    if (error != nil) {
        NSLog(@"Error: %@", error);
        return nil;
    }
    
    return sample;
}

数学运算

随机数

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arc4random() % 10000

设计模式

协议

检测协议的实现者是否实现遵循了某个协议方法

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//        如果设置了 init View，则将 init View 设置到中间
        if (self.delegate?.respondsToSelector("initialViewIndexForHorizontalScroller") != false)
        {
            //println(self.delegate?.respondsToSelector("initialViewIndexForHorizontalScroller"))
            
            var initialView:CGFloat = CGFloat(self.delegate.initialViewIndexForHorizontalScroller!(self))
            
            scroller.setContentOffset(CGPointMake(initialView * (VIEW_DIMENSIONS + (2 * VIEW_PADDING)), 0), animated: true)
        }

swift 中定义协议

如果协议继承自 Objective-C 的类，那么协议前面需要加上 @objc。

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@objc protocol HorizontalScrollerDelegate:NSObjectProtocol{
    
    //ask the delegate how many view he wants present inside the horizontal scroller
    func numberOfViewsForHorizontalScroller(scroller:HorizontalScroller)->NSInteger
    //ask the delegate to reuturn the view that should appear at <index>
    func horizontalScroller(scroller:HorizontalScroller,viewAtIndex:Int)->UIView
    //inform the delegate what the view at <index> has been clicked
    func horizontalScroller(scroller:HorizontalScroller,clickedViewIndex:Int)
    
    
//    ask the delegate for the index of the inital view to display.this method is optional
//    and default to 0 if it's not implemented by the delegate
    optional func initialViewIndexForHorizontalScroller(scroller:HorizontalScroller)->NSInteger
    
    
    
}

界面

圆形图片和气泡对话框

圆形图片

使用 setCornerRadius 设置图片的边角弧度，如果想让图片周围显示一个圆圈线条，可以在图片上面添加一个透明背景的圆圈图片

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[[self.cover layer] setMasksToBounds:YES];
[[self.cover layer] setCornerRadius:[self.cover cw_width]/2];

界面跳转

If you’re in a Navigation Controller:

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ViewController *viewController = [[ViewController alloc] init];
[self.navigationController pushViewController:viewController animated:YES];

or if you just want to present a new view:

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ViewController *viewController = [[ViewController alloc] init];    
[self presentViewController:viewController animated:YES completion:nil];

动画效果

内容来自极客学院视频

进度条效果

PrgresssView.swift：

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class PrgresssView: UIView {

   // private var progress:UIView!
    private var progressLayer:CALayer!
    private var progressPersent:CGFloat = 0
    private var progerssWidth:CGFloat = 0
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        
        
        progressLayer = CALayer()
        progressLayer.frame = CGRectMake(0, 0, 0, frame.size.height)
        
        progressLayer.backgroundColor = UIColor(red: 1.0, green: 0.8288, blue: 0.0, alpha: 1.0).CGColor
        //self.layer.backgroundColor = UIColor(red: 0.4812, green: 0.0477, blue: 0.0, alpha: 1.0).CGColor
        self.layer.addSublayer(progressLayer)
        
        progerssWidth = frame.size.width
    }

    func setProgressPersent(progress:CGFloat)
    {
        progressPersent = progress
        if(progressPersent <= 0)
        {
            self.progressLayer.frame = CGRectMake(0, 0, 0, self.frame.size.height)
        }else if (progressPersent <= 1)
        {
            self.progressLayer.frame = CGRectMake(0, 0, progressPersent*self.progerssWidth, self.frame.size.height)
        }else
        {
            self.progressLayer.frame = CGRectMake(0, 0, self.progerssWidth, self.frame.size.height)
        }
        
    }
    func getProgressPersent()
    {
        
    }
    
    required init(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    // Only override drawRect: if you perform custom drawing.
    // An empty implementation adversely affects performance during animation.
    override func drawRect(rect: CGRect) {
        // Drawing code
    }
}

ViewController.swift:

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class ViewController: UIViewController {

    private var layer:CALayer!
    
    private var _processView:PrgresssView = PrgresssView(frame: CGRectMake(0, 300, 300, 10))
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        var timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "layerAnimation", userInfo: nil, repeats: true)
        
        
        _processView.backgroundColor = UIColor ( red: 0.5723, green: 0.5723, blue: 0.5723, alpha: 0.0 )
        _processView.layer.borderWidth = 1
        self.view.addSubview(_processView)
        
        
    }
    func layerAnimation()
    {
        _processView.setProgressPersent(CGFloat(arc4random_uniform(100))/100)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

图片过渡效果和组合动画

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class ViewController: UIViewController {

    private var imageLayer:CALayer!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        var image1:UIImage = UIImage(named: "1.jpeg")!
        
        self.imageLayer = CALayer()
        self.imageLayer.frame = CGRectMake(0, 0, 510, 771)
        self.view.layer.addSublayer(self.imageLayer)
        
        self.imageLayer.contents = image1.CGImage
        var timer = NSTimer.scheduledTimerWithTimeInterval(3, target: self, selector: "layerAnimation", userInfo: nil, repeats: false)
    }
    func layerAnimation(){
        var image2:UIImage = UIImage(named: "2.jpeg")!
        //self.imageLayer.contents = image2.CGImage
        
        /* 2015-08-03 20:57:53
        
        这段动画只是提交了上去，并没有修改 CALayer 的内容。
        提交完成后会立刻恢复动画之前的状态，所有需要动画完成后手动修改CALayer 值
        */
        //图片动画
        var contentsAnimation:CABasicAnimation = CABasicAnimation(keyPath: "contents")
        contentsAnimation.fromValue = self.imageLayer.contents
        contentsAnimation.toValue = image2.CGImage
        contentsAnimation.duration = 3
        
        //bounds 动画
        var boundsAnimation:CABasicAnimation = CABasicAnimation(keyPath: "bounds")
        boundsAnimation.fromValue = NSValue(CGRect: self.imageLayer.bounds)
        boundsAnimation.toValue = NSValue(CGRect: CGRectMake(0, 0, 510/2, 771/2))
        boundsAnimation.duration = 3
        
        //组合动画
        var groupAnimation:CAAnimationGroup = CAAnimationGroup()
        groupAnimation.animations = [contentsAnimation,boundsAnimation]
        groupAnimation.duration = 3
        
        self.imageLayer.bounds = CGRectMake(0, 0, 510/2, 771/2)
        self.imageLayer.contents = image2.CGImage
        
        //单个动画
        //self.imageLayer.addAnimation(contentsAnimation, forKey: nil)
        
        //组合动画
        self.imageLayer.addAnimation(groupAnimation, forKey: nil)
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

CALayer 遮罩效果

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class ViewController: UIViewController {

    var imageLayer:CALayer!
    var maskLayer:CALayer!
    
    var imageContent:UIImage!
    var maskContents:UIImage!
  
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        self.imageContent=UIImage(named: "1.jpeg")
        self.maskContents = UIImage(named: "3.png")
        
        self.imageLayer = CALayer()
        self.imageLayer.frame = CGRectMake(50, 50, 200, 200)
        self.imageLayer.contents = imageContent.CGImage
        self.view.layer.addSublayer(imageLayer)
        
        
        self.maskLayer = CALayer()
        self.maskLayer.frame = self.imageLayer.bounds
        self.maskLayer.contents = self.maskContents.CGImage
        
        //给图片提供遮罩的 layer
        self.imageLayer.mask = self.maskLayer
        
        var timer = NSTimer.scheduledTimerWithTimeInterval(3, target: self, selector: "maskLayerAnimation", userInfo: nil, repeats: false)
        
    }
    func maskLayerAnimation(){
        self.maskLayer.frame = CGRectMake(50, 50, 200, 200)
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

Core Graphic 绘图

内容来自极客学院视频

画线

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override func drawRect(rect: CGRect) {
        var context = UIGraphicsGetCurrentContext()
        
        CGContextMoveToPoint(context,100, 100)
        CGContextAddLineToPoint(context,100, 200)
        CGContextAddLineToPoint(context, 200, 200)
        
        
        CGContextMoveToPoint(context, 100, 300)
        CGContextAddLineToPoint(context, 100, 400)
        CGContextAddLineToPoint(context, 200, 500)
        
        CGContextSetRGBStrokeColor(context, 1, 0, 1, 1)
        CGContextSetLineWidth(context, 5)
        
        CGContextStrokePath(context)
    }

画矩形

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override func drawRect(rect: CGRect) {
       // Drawing code
       var context = UIGraphicsGetCurrentContext()
       CGContextAddRect(context, CGRect(x: 100, y: 100, width: 100, height: 100))
       CGContextSetRGBFillColor(context, 1, 0, 0, 1)
       CGContextFillPath(context)
       CGContextSetLineWidth(context, 5)
       CGContextSetRGBStrokeColor(context, 0, 1, 0, 1)
       CGContextStrokeRect(context, CGRect(x: 100, y: 100, width: 100, height: 100))
       
   }

画圆形

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override func drawRect(rect: CGRect) {
        // Drawing code
        var context = UIGraphicsGetCurrentContext()
        
        CGContextAddArc(context, 150, 200, 100,0 , 3.141592653*2,0)
        CGContextSetRGBStrokeColor(context, 1, 0, 0, 1)
        CGContextFillPath(context)
        
        CGContextAddArc(context,150,200,100,0,3.141592653*2,0)
        CGContextSetLineWidth(context, 10)
        CGContextStrokePath(context)
        
        CGContextAddEllipseInRect(context, CGRect(x: 50, y: 400, width: 200, height: 100))
        CGContextStrokePath(context)
    }

画图片

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class DrawImage: UIView {

    var uiImage:CGImageRef!
    
    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        
        uiImage = UIImage(named: "walle.jpg")?.CGImage
        
    }
    
    // Only override drawRect: if you perform custom drawing.
    // An empty implementation adversely affects performance during animation.
    override func drawRect(rect: CGRect) {
        // Drawing code
        
        var context = UIGraphicsGetCurrentContext()
        
        CGContextSaveGState(context)
        
        CGContextTranslateCTM(context, 10, 400)
        CGContextScaleCTM(context, 1, -1)
        CGContextDrawImage(context, CGRect(x: 0, y: 0, width: 200, height: 200), uiImage)
        
        //恢复之前的 context，避免处理单个图片时影响到整个 context 的状态。
        CGContextRestoreGState(context)
        
        //如果没有恢复之前的context，会影响到后续的执行。
        CGContextStrokeRect(context, CGRect(x: 50, y: 100, width: 100, height: 100))
        
    }
}

绘画板

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// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func drawRect(rect: CGRect) {
    var context = UIGraphicsGetCurrentContext()
    CGContextAddPath(context, path)
    CGContextStrokePath(context)
}
var path = CGPathCreateMutable()

override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
   var p =  (touches.first as! UITouch).locationInView(self)
    CGPathMoveToPoint(path, nil, p.x, p.y)
}
override func touchesMoved(touches: Set<NSObject>, withEvent event: UIEvent) {
    var p =  (touches.first as! UITouch).locationInView(self)
    CGPathAddLineToPoint(path, nil, p.x, p.y)
    setNeedsDisplay()
}

注册手势点击事件和检测发生点击所对应的视图

1.注册手势检测

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- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self)
    {
        scroller = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, frame.size.width, frame.size.height)];
        scroller.delegate = self;
        [self addSubview:scroller];
        
        //在这里注册
        UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(scrollerTapped:)];
        [scroller addGestureRecognizer:tapRecognizer];
    }
    return self;
}

然后在 scrollerTapped 检测哪个 UIView 被选中。
检测完成后设置选中的 UIView 居中，并发送 delegate 消息通知协议实现者哪个视图发生了点击。

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- (void)scrollerTapped:(UITapGestureRecognizer*)gesture
{
    CGPoint location = [gesture locationInView:gesture.view];
    // we can't use an enumerator here, because we don't want to enumerate over ALL of the UIScrollView subviews.
    // we want to enumerate only the subviews that we added
    for (int index=0; index<[self.delegate numberOfViewsForHorizontalScroller:self]; index++)
    {
        UIView *view = scroller.subviews[index];
        if (CGRectContainsPoint(view.frame, location))
        {
            [self.delegate horizontalScroller:self clickedViewAtIndex:index];
            [scroller setContentOffset:CGPointMake(view.frame.origin.x - self.frame.size.width/2 + view.frame.size.width/2, 0) animated:YES];
            break;
        }
    }
}

手撸界面

手撸 UITableView

ViewDidLoad：

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self.view.backgroundColor = UIColor(red: 0.76, green: 0.81, blue: 0.87, alpha: 1)
        currentAlbumIndex = 0;
        
        allAlbums = LibraryAPI.sharedInstance.getAlbums()
        
        //呈现 album 数据
        
        dataTable = UITableView(frame: CGRectMake(0, 120, self.view.frame.size.width, self.view.frame.size.height-120), style:UITableViewStyle.Grouped)
        dataTable.delegate=self
        dataTable.dataSource=self
        dataTable.backgroundView=nil
        self.view.addSubview(dataTable)

cellForRowAtIndexPath：

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func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
   {
       var cell = tableView.dequeueReusableCellWithIdentifier("cell")  as? UITableViewCell
       

       if cell == nil {
           cell = UITableViewCell(style: UITableViewCellStyle.Value1, reuseIdentifier: "cell")
       }
       
       cell?.textLabel!.text = currentAlbumData["titles"]!.objectAtIndex(indexPath.row) as? String
       cell?.detailTextLabel?.text = currentAlbumData["values"]!.objectAtIndex(indexPath.row) as? String
       
       return cell!
   }

Objective-C 混合 Swift

Objective-C 调用 Swift

在需要调用 Swift 方法的 .h文件顶部添加 #import 工程名称-Swift.h，即可在 Objective-C 中使用 Swift 的类

Swift 调用 Objective-C

在桥接文件加入需要调用的 Objective-C 的 .h 文件即可

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#ifndef CycleMemory_CycleMemory_Bridging_Header_h
#define CycleMemory_CycleMemory_Bridging_Header_h

#include "CycleMemoryApi.h"

#endif

枚举

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typedef NS_ENUM(NSInteger, AFNetworkReachabilityStatus) {
    AFNetworkReachabilityStatusUnknown          = -1,
    AFNetworkReachabilityStatusNotReachable     = 0,
    AFNetworkReachabilityStatusReachableViaWWAN = 1,
    AFNetworkReachabilityStatusReachableViaWiFi = 2,
};
#iOS
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