UIView的小小总结

慢慢吞吞的学iOS开发，也总算是有了一点进展，UI基础都过了一遍，今天回顾一下之前学的东西，做个总结

//枚举

//UIview的动画形成

typedef NS_ENUM(NSInteger, UIViewAnimationCurve) {

UIViewAnimationCurveEaseInOut,         // slow at beginning and end  开头结尾慢

UIViewAnimationCurveEaseIn,            // slow at beginning

UIViewAnimationCurveEaseOut,           // slow at end

UIViewAnimationCurveLinear

};

typedef NS_ENUM(NSInteger, UIViewContentMode) {

UIViewContentModeScaleToFill,

UIViewContentModeScaleAspectFit,      // contents scaled to fit with fixed aspect. remainder is transparent  内容按比例适应view

UIViewContentModeScaleAspectFill,     // contents scaled to fill with fixed aspect. some portion of content may be clipped.  内容填充view，按内容比例，不会改变内容比例

UIViewContentModeRedraw,              // redraw on bounds change (calls -setNeedsDisplay)

UIViewContentModeCenter,              // contents remain same size. positioned adjusted.

UIViewContentModeTop,

UIViewContentModeBottom,

UIViewContentModeLeft,

UIViewContentModeRight,

UIViewContentModeTopLeft,

UIViewContentModeTopRight,

UIViewContentModeBottomLeft,

UIViewContentModeBottomRight,

};

//注意以上几个常量，凡是没有带Scale的，当图片尺寸超过 ImageView尺寸时，只有部分显示在ImageView中。UIViewContentModeScaleToFill属性会导致图片变形。UIViewContentModeScaleAspectFit会保证图片比例不变，而且全部显示在ImageView中，这意味着ImageView会有部分空白。UIViewContentModeScaleAspectFill也会证图片比例不变，但是是填充整个ImageView的，可能只有部分图片显示出来

@interface UIView(UIViewHierarchy)

@property(nonatomic,readonly) UIView       *superview;
@property(nonatomic,readonly,copy) NSArray *subviews;
@property(nonatomic,readonly) UIWindow     *window;

- (void)removeFromSuperview;
- (void)insertSubview:(UIView *)view atIndex:(NSInteger)index;
- (void)exchangeSubviewAtIndex:(NSInteger)index1 withSubviewAtIndex:(NSInteger)index2;

- (void)addSubview:(UIView *)view;
- (void)insertSubview:(UIView *)view belowSubview:(UIView *)siblingSubview;
- (void)insertSubview:(UIView *)view aboveSubview:(UIView *)siblingSubview;

- (void)bringSubviewToFront:(UIView *)view;
- (void)sendSubviewToBack:(UIView *)view;

// Allows you to perform layout before the drawing cycle happens. -layoutIfNeeded forces layout early
- (void)setNeedsLayout;
- (void)layoutIfNeeded;

- (void)layoutSubviews;    // override point. called by layoutIfNeeded automatically. As of iOS 6.0, when constraints-based layout is used the base implementation applies the constraints-based layout, otherwise it does nothing.

@end

刷新子对象布局

-layoutSubviews方法：这个方法，默认没有做任何事情，需要子类进行重写
-setNeedsLayout方法： 标记为需要重新布局，异步调用layoutIfNeeded刷新布局，不立即刷新，但layoutSubviews一定会被调用
-layoutIfNeeded方法：如果，有需要刷新的标记，立即调用layoutSubviews进行布局（如果没有标记，不会调用layoutSubviews）

如果要立即刷新，要先调用[view setNeedsLayout]，把标记设为需要布局，然后马上调用[view layoutIfNeeded]，实现布局

在视图第一次显示之前，标记总是“需要刷新”的，可以直接调用[view layoutIfNeeded]

@interface UIView(UIViewRendering)

- (void)drawRect:(CGRect)rect;

- (void)setNeedsDisplay;
- (void)setNeedsDisplayInRect:(CGRect)rect;

@property(nonatomic)                 BOOL              clipsToBounds;              // When YES, content and subviews are clipped to the bounds of the view. Default is NO.
@property(nonatomic,copy)            UIColor          *backgroundColor UI_APPEARANCE_SELECTOR; // default is nil. Can be useful with the appearance proxy on custom UIView subclasses.
@property(nonatomic)                 CGFloat           alpha;                      // animatable. default is 1.0
@property(nonatomic,getter=isOpaque) BOOL              opaque;                     // default is YES. opaque views must fill their entire bounds or the results are undefined. the active CGContext in drawRect: will not have been cleared and may have non-zeroed pixels
@end

重绘

-drawRect:(CGRect)rect方法：重写此方法，执行重绘任务
-setNeedsDisplay方法：标记为需要重绘，异步调用drawRect
-setNeedsDisplayInRect:(CGRect)invalidRect方法：标记为需要局部重绘

layoutSubviews对subviews重新布局

layoutSubviews方法调用先于drawRect

setNeedDisplay在receiver标上一个需要被重新绘图的标记，在下一个draw周期自动重绘，iphone device的刷新频率是60hz，也就是1/60秒后重绘

UIView的setNeedsDisplay和setNeedsLayout方法。首先两个方法都是异步执行的。setNeedsDisplay会调用自动调用drawRect方法，这样可以拿到UIGraphicsGetCurrentContext，就可以画画了。而setNeedsLayout会默认调用layoutSubViews，就可以处理子视图中的一些数据。

综上两个方法都是异步执行的，layoutSubviews方便数据计算，drawRect方便视图重绘。

*************************Animation*********************

UIview的动画

@interface UIView(UIViewAnimation)

+ (void)beginAnimations:(NSString *)animationID context:(void *)context;  // additional context info passed to will start/did stop selectors. begin/commit can be nested
+ (void)commitAnimations;                                                 // starts up any animations when the top level animation is commited

// no getters. if called outside animation block, these setters have no effect.
+ (void)setAnimationDelegate:(id)delegate;                          // default = nil
+ (void)setAnimationWillStartSelector:(SEL)selector;                // default = NULL. -animationWillStart:(NSString *)animationID context:(void *)context
+ (void)setAnimationDidStopSelector:(SEL)selector;                  // default = NULL. -animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context
+ (void)setAnimationDuration:(NSTimeInterval)duration;              // default = 0.2
+ (void)setAnimationDelay:(NSTimeInterval)delay;                    // default = 0.0
+ (void)setAnimationStartDate:(NSDate *)startDate;                  // default = now ([NSDate date])
+ (void)setAnimationCurve:(UIViewAnimationCurve)curve;              // default = UIViewAnimationCurveEaseInOut
+ (void)setAnimationRepeatCount:(float)repeatCount;                 // default = 0.0.  May be fractional
+ (void)setAnimationRepeatAutoreverses:(BOOL)repeatAutoreverses;    // default = NO. used if repeat count is non-zero
+ (void)setAnimationBeginsFromCurrentState:(BOOL)fromCurrentState;  // default = NO. If YES, the current view position is always used for new animations -- allowing animations to "pile up" on each other. Otherwise, the last end state is used for the animation (the default).

+ (void)setAnimationTransition:(UIViewAnimationTransition)transition forView:(UIView *)view cache:(BOOL)cache;  // current limitation - only one per begin/commit block

+ (void)setAnimationsEnabled:(BOOL)enabled;                         // ignore any attribute changes while set.
+ (BOOL)areAnimationsEnabled;
+ (void)performWithoutAnimation:(void (^)(void))actionsWithoutAnimation NS_AVAILABLE_IOS(7_0);

@end

例子：（头尾式）在viewDidload中调用

//UIView动画
- (void)test1{
    //1.UIView动画
    [UIView beginAnimations:nil context:nil];
    //设置时间
    [UIView setAnimationDuration:2];
    //监听动画的完成
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDidStopSelector:@selector(stop)];

    //实现动画代码
    self.imageView.center = CGPointMake(250, 250);　　//提交动画
    [UIView commitAnimations];
}

- (void)stop{
    NSLog(@"%s",__func__);

}

UIView动画的第二种方法：block

//2.UIView的block动画
- (void)test2{
    [UIView animateWithDuration:2 animations:^{
        self.imageView.center = CGPointMake(250, 250);
    } completion:^(BOOL finished) {
        NSLog(@"动画完成");
    }];

}

UIView的转场动画使用:

//3.UIView的转场动画
- (void)test3{
    [UIView transitionWithView:self.imageView duration:3 options:UIViewAnimationOptionTransitionFlipFromBottom animations:^{
        self.imageView.image = [UIImage imageNamed:@"fc1f4134970a304e9a8f631ed0c8a786c8175ca1"];
    } completion:^(BOOL finished) {
        NSLog(@"完成翻页");
    }];//翻页效果:从底部进入

}