(8/18)重学Standford_iOS7开发_协议、block、动画_课程笔记

//协议一般放于.h文件中或者在类的.h文件中@protocol Foo <Xyzzy, NSObject>//<>中的内容表示还需实现自哪些协议，所有协议的根协议一般都是NSObject- (void)someMethod;//默认为必须实现的方法@optional//可选方法声明- (void)methodWithArgument:(BOOL)argument;@required@property (readonly) int readonlyProperty; //只有getter在协议中@property NSString *readwriteProperty; //getter与setter都在协议中 - (int)methodThatReturnsSomething;@end

#import “Foo.h” @interface MyClass : NSObject <Foo> //(do not have to declare Foo’s methods again here, it’s implicit that you implement it)@end//或者私有实现@interface MyClass() <Foo>@end@implementation MyClass//@required methods here! @end

//UI与controller盲通信的方式@property (nonatomic, weak) id <UISomeObjectDelegate> delegate;@property (nonatomic, weak) id <UISomeObjectDataSource> dataSource;

int multiplier = 7;int (^myBlock)(int) = ^(int num) {    return num * multiplier;};//int 为block返回值 //^表示为此为代码块//myBlock为此代码块名//int 为参数类型//等号右边为block实现

int multiplier = 7;int (^myBlock)(int) = ^(int num) {    return num * multiplier;}; printf("%d", myBlock(3));// prints "21"

char *myCharacters[3] = { "TomJohn", "George", "Charles Condomine" };//直接使用block作为参数 qsort_b(myCharacters, 3, sizeof(char *), ^(const void *l, const void *r) {    char *left = *(char **)l;    char *right = *(char **)r;    return strncmp(left, right, 1);}); // myCharacters is now { "Charles Condomine", "George", "TomJohn" } 

NSArray *stringsArray = @[ @"string 1",                           @"String 21",                           @"string 12",                           @"String 11",                           @"String 02" ]; static NSStringCompareOptions comparisonOptions = NSCaseInsensitiveSearch | NSNumericSearch |        NSWidthInsensitiveSearch | NSForcedOrderingSearch;NSLocale *currentLocale = [NSLocale currentLocale]; //比较器为代码块NSComparator finderSortBlock = ^(id string1, id string2) {    NSRange string1Range = NSMakeRange(0, [string1 length]);    return [string1 compare:string2 options:comparisonOptions range:string1Range locale:currentLocale];}; NSArray *finderSortArray = [stringsArray sortedArrayUsingComparator:finderSortBlock];NSLog(@"finderSortArray: %@", finderSortArray); /*Output:finderSortArray: (    "string 1",    "String 02",    "String 11",    "string 12",    "String 21")*/

//直接使用变量int x = 123; void (^printXAndY)(int) = ^(int y) {    printf("%d %d/n", x, y);}; printXAndY(456); // prints: 123 456//不可以直接更改变量，此处变量对block来说为只读int x = 123;void (^printXAndY)(int) = ^(int y) {    x = x + y; // error    printf("%d %d/n", x, y);};

__block int x = 123; //  x lives in block storage void (^printXAndY)(int) = ^(int y) {    x = x + y;    printf("%d %d/n", x, y);};printXAndY(456); // prints: 579 456// x is now 579

//注意block的调用时机extern NSInteger CounterGlobal;//block对全局变量有读写权限static NSInteger CounterStatic;//静态变量{    NSInteger localCounter = 42;//普通本地变量    __block char localCharacter;//__block本地变量     void (^aBlock)(void) = ^(void) {        ++CounterGlobal;        ++CounterStatic;        CounterGlobal = localCounter; // localCounter fixed at block creation        localCharacter = 'a'; // sets localCharacter in enclosing scope    };     ++localCounter; // unseen by the block，对block不可见，block的值认为42    localCharacter = 'b';     aBlock(); // execute the block    // localCharacter now 'a'}

dispatch_async(queue, ^{    /*     block中访问实例变量，instanceVariable为block所在类的实例变量，此时直接访问了实例变量，因此需要对包含它的对象（self）保留    */    doSomethingWithObject(_instanceVariable);});  id localVariable = _instanceVariable;dispatch_async(queue, ^{    /*    在本地创建了指向实例变量的引用，因此需要保留localVariable而不是self    */    doSomethingWithObject(localVariable);});

typedef float (^MyBlockType)(float, float); MyBlockType myFirstBlock = // ... ;MyBlockType mySecondBlock = // ... ;

//block中引用self，所以有强指针指向self，而block又在self中定义，所以self又有强指针指向block[self.myBlocks addObject:^ {    [self doSomething];}];

__weak MyClass *weakSelf = self; //重新声明为弱引用[self.myBlocks addObject:^ {    [weakSelf doSomething];}];

+ (void)animateWithDuration:(NSTimeInterval)duration                                  delay:(NSTimeInterval)delay                               options:(UIViewAnimationOptions)options                          animations:(void (^)(void))animations                          completion:(void (^)(BOOL finished))completion;//适用于常规动画设置//example[UIView animateWithDuration:3.0                      delay:0.0                    options:UIViewAnimationOptionBeginFromCurrentState                 animations:^{ myView.alpha = 0.0; }                 completion:^(BOOL fin) { if (fin) [myView removeFromSuperview]; }];//视图在3秒内从父视图淡出，完成动画后并移除自己+ (void)transitionWithView:(UIView *)view                  duration:(NSTimeInterval)duration                   options:(UIViewAnimationOptions)options                animations:(void (^)(void))animations                completion:(void (^)(BOOL finished))completion;//适用于转场动画设置,比如卡牌的翻转+ (void)transitionFromView:(UIView *)fromView                    toView:(UIView *)toView                  duration:(NSTimeInterval)duration                   options:(UIViewAnimationOptions)options                completion:(void (^)(BOOL finished))completion;//适用于切换视图动画

//UIViewAnimationOptions//常规动画属性设置（可以同时选择多个进行设置）UIViewAnimationOptionLayoutSubviews          //父视图变化时自动更新子视图约束@see:http://segmentfault.com/q/1010000002872390 UIViewAnimationOptionAllowUserInteraction      //动画时响应用户事件，如 touch等   UIViewAnimationOptionBeginFromCurrentState     //从当前状态开始动画，比如此时有动画正在改变属性UIViewAnimationOptionRepeat                    //无限制重复动画UIViewAnimationOptionAutoreverse               //执行动画回路(动画运行到结束点后仍然以动画方式回到初始点),前提是设置动画无限重复UIViewAnimationOptionOverrideInheritedDuration //忽略嵌套动画时间设置UIViewAnimationOptionOverrideInheritedCurve    //忽略嵌套动画速度设置UIViewAnimationOptionAllowAnimatedContent      //动画过程中重绘视图（注意仅仅适用于转场动画）UIViewAnimationOptionShowHideTransitionViews   //视图切换时直接隐藏旧视图、显示新视图，而不是将旧视图从父视图移除（仅仅适用于转场动画）UIViewAnimationOptionOverrideInheritedOptions  //不继承父动画设置或动画类型//动画速度控制（可从其中选择一个设置）UIViewAnimationOptionCurveEaseInOut           //动画先缓慢，然后逐渐加速UIViewAnimationOptionCurveEaseIn               //动画逐渐变慢UIViewAnimationOptionCurveEaSEOut              //动画逐渐加速UIViewAnimationOptionCurveLinear              //动画匀速执行，默认值//转场类型（仅适用于转场动画设置，可以从中选择一个进行设置，基本动画、关键帧动画不需要设置）UIViewAnimationOptionTransitionNone            //没有转场动画效果UIViewAnimationOptionTransitionFlipFromLeft    //从左侧翻转效果UIViewAnimationOptionTransitionFlipFromRight   //从右侧翻转效果UIViewAnimationOptionTransitionCurlUp          //向后翻页的动画过渡效果UIViewAnimationOptionTransitionCurlDown        //向前翻页的动画过渡效果UIViewAnimationOptionTransitionCrossDissolve   //旧视图溶解消失显示下一个新视图的效果UIViewAnimationOptionTransitionFlipFromTop     //从上方翻转效果UIViewAnimationOptionTransitionFlipFromBottom  //从底部翻转效果

//Create a UIDynamicAnimatorUIDynamicAnimator *animator = [[UIDynamicAnimator alloc] initWithReferenceView:aView];//Create and add UIDynamicBehaviorsUIGravityBehavior *gravity = [[UIGravityBehavior alloc] init]; [animator addBehavior:gravity];UICollisionBehavior *collider = [[UICollisionBehavior alloc] init]; [animator addBehavior:collider];//Add UIDynamicItems to a UIDynamicBehaviorid <UIDynamicItem> item1 = ...; id <UIDynamicItem> item2 = ...; [gravity addItem:item1]; [collider addItem:item1]; [gravity addItem:item2];

//UIDynamicItem 协议@protocol UIDynamicItem@property (readonly) CGRect bounds;@property (readwrite) CGPoint center;@property (readwrite) CGAffineTransform transform; @end//一般UIView即可作为Item，天生实现了UIDynamic协议//以上属性一般有动画运行时的animator来改变，若需要主动改变，需要调用- (void)updateItemUsingCurrentState:(id <UIDynamicItem>)item;

//UIGravityBehavior@property CGFloat angle;//重力方向，默认向下@property CGFloat magnitude; // 1.0 is 1000 points/s/s//UICollisionBehavior 碰撞@property UICollisionBehaviorMode collisionMode; // Items,Boundaries,Everything (default) - (void)addBoundaryWithIdentifier:(NSString *)identifier forPath:(UIBezierPath *)path; //用UIBezierPath自定义碰撞边界@property BOOL translatesReferenceBoundsIntoBoundary;//参考视图（动力动画的顶级视图）作为碰撞边界//UIAttachmentBehavior 吸附行为- (instancetype)initWithItem:(id <UIDynamicItem>)item attachedToAnchor:(CGPoint)anchor;//以点作为吸附- (instancetype)initWithItem:(id <UIDynamicItem>)i1 attachedToItem:(id <UIDynamicItem>)i2;//以动力项作为吸附,两个动力项的吸附- (instancetype)initWithItem:(id <UIDynamicItem>)item offsetFromCenter:(CGPoint)offset ... //偏移中心的吸附@property (readwrite) CGFloat length; // 吸附的长度@property (readwrite) CGPoint anchorPoint; // 吸附点@property (readwrite, nonatomic) CGFloat damping; // 锚点移动时的阻尼@property (readwrite, nonatomic) CGFloat frequency; // 锚点移动时的频率//UISnapBehavior 捕捉行为- (instancetype)initWithItem:(id <UIDynamicItem>)item snapToPoint:(CGPoint)point; @property CGFloat damping;.//移动到锚点时振动的阻尼//UIPushBehavior 推动行为@property UIPushBehaviorMode mode; // Continuous or Instantaneous@property CGVector pushDirection;@property CGFloat magnitude/angle; // magnitude 1.0 moves a 100x100 view at 100 pts/s/s//UIDynamicItemBehavior 动力项行为，应用于所有Items@property (readwrite, nonatomic) CGFloat elasticity; // 弹力，[0.1]@property (readwrite, nonatomic) CGFloat friction; //摩擦力，0表示无摩擦力@property (readwrite, nonatomic) CGFloat density; // 密度，默认为1@property (readwrite, nonatomic) CGFloat resistance; //线性阻力系数0--CGFLOAT_MAX@property (readwrite, nonatomic) CGFloat angularResistance; //角度阻力系数0--CGFLOAT_MAX@property (readwrite, nonatomic) BOOL allowsRotation; //是否允许旋转- (CGPoint)linearVelocityForItem:(id <UIDynamicItem>)item;//获取Item速度- (CGFloat)angularVelocityForItem:(id <UIDynamicItem>)item;//获取Item角速度

- (void)addChildBehavior:(UIDynamicBehavior *)behavior;//将其他行为添加到自定义行为中@property UIDynamicAnimator *dynamicAnimator;//获取当前行为所在的Animator- (void)willMoveToAnimator:(UIDynamicAnimator *)animator;//行为加入到方法或者移除时（此时参数为nil）会调用@property (copy) void (^action)(void);//每当行为发生时总会执行此block，注意调用比较频繁的效率问题