查詢時間或長或短，為了提升用戶體驗，目前用的比較多的手段之一就是查詢等待時添加一個動態(tài)等待效果。當我們在請求網(wǎng)絡(luò)時加載頁面時有個動作效果，效果圖如下：
源代碼可以網(wǎng)上找開源項目Coding.net，上面的效果原理為兩張圖片組合，外面那個則為動畫轉(zhuǎn)動，里面的圖標則是透明度的變化；主要代碼如下：
1：把它封裝在EaseLoadingView里面
@interface EaseLoadingView : UIView@property (strong, nonatomic) UIImageView *loopView, *monkeyView;@property (assign, nonatomic, readonly) BOOL isLoading;- (void)startAnimating;- (void)stopAnimating;@end@interface EaseLoadingView ()@property (nonatomic, assign) CGFloat loopAngle, monkeyAlpha, angleStep, alphaStep;@end@implementation EaseLoadingView- (instancetype)initWithFrame:(CGRect)frame{ self = [super initWithFrame:frame]; if (self) { self.backgroundColor = [UIColor clearColor]; _loopView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"loading_loop"]]; _monkeyView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"loading_monkey"]]; [_loopView setCenter:self.center]; [_monkeyView setCenter:self.center]; [self addSubview:_loopView]; [self addSubview:_monkeyView]; [_loopView mas_makeConstraints:^(MASConstraintMaker *make) { make.center.equalTo(self); }]; [_monkeyView mas_makeConstraints:^(MASConstraintMaker *make) { make.center.equalTo(self); }]; _loopAngle = 0.0; _monkeyAlpha = 1.0; _angleStep = 360/3; _alphaStep = 1.0/3.0; } return self;}- (void)startAnimating{ self.hidden = NO; if (_isLoading) { return; } _isLoading = YES; [self loadingAnimation];}- (void)stopAnimating{ self.hidden = YES; _isLoading = NO;}- (void)loadingAnimation{ static CGFloat duration = 0.25f; _loopAngle += _angleStep; if (_monkeyAlpha >= 1.0 || _monkeyAlpha <= 0.0) { _alphaStep = -_alphaStep; } _monkeyAlpha += _alphaStep; [UIView animateWithDuration:duration delay:0.0 options:UIViewAnimationOptionCurveLinear animations:^{ CGAffineTransform loopAngleTransform = CGAffineTransformMakeRotation(_loopAngle * (M_PI / 180.0f)); _loopView.transform = loopAngleTransform; _monkeyView.alpha = _monkeyAlpha; } completion:^(BOOL finished) { if (_isLoading && [self superview] != nil) { [self loadingAnimation]; }else{ [self removeFromSuperview]; _loopAngle = 0.0; _monkeyAlpha = 1,0; _alphaStep = ABS(_alphaStep); CGAffineTransform loopAngleTransform = CGAffineTransformMakeRotation(_loopAngle * (M_PI / 180.0f)); _loopView.transform = loopAngleTransform; _monkeyView.alpha = _monkeyAlpha; } }];}@end注意loadingAnimation這里面有動作的處理及透明度的處理，當停止加載后把它自個從當前的視圖去除；
2：UIView (Common)在UIView擴展類里
#pragma mark LoadingView@property (strong, nonatomic) EaseLoadingView *loadingView;- (void)beginLoading;- (void)endLoading;@end- (void)setLoadingView:(EaseLoadingView *)loadingView{ [self willChangeValueForKey:@"LoadingViewKey"]; objc_setAssociatedObject(self, &LoadingViewKey, loadingView, OBJC_ASSOCIATION_RETAIN_NONATOMIC); [self didChangeValueForKey:@"LoadingViewKey"];}- (EaseLoadingView *)loadingView{ return objc_getAssociatedObject(self, &LoadingViewKey);}- (void)beginLoading{ for (UIView *aView in [self.blankPageContainer subviews]) { if ([aView isKindOfClass:[EaseBlankPageView class]] && !aView.hidden) { return; } } if (!self.loadingView) { //初始化LoadingView self.loadingView = [[EaseLoadingView alloc] initWithFrame:self.bounds]; } [self addSubview:self.loadingView]; [self.loadingView mas_makeConstraints:^(MASConstraintMaker *make) { make.self.edges.equalTo(self); }]; [self.loadingView startAnimating];}- (void)endLoading{ if (self.loadingView) { [self.loadingView stopAnimating]; }}注意：cocoa的KVO模型中，有兩種通知觀察者的方式，自動通知和手動通知。顧名思義，自動通知由cocoa在屬性值變化時自動通知觀察者，而手動通知需要在值變化時調(diào)用 willChangeValueForKey:和didChangeValueForKey: 方法通知調(diào)用者。
3：使用頁面調(diào)用
- (void)sendRequest{ [self.view beginLoading]; __weak typeof(self) weakSelf = self; [[Coding_NetAPIManager sharedManager] request_CodeFile:_myCodeFile withPro:_myProject andBlock:^(id data, NSError *error) { [weakSelf.view endLoading]; if (data) { weakSelf.myCodeFile = data; [weakSelf refreshCodeViewData]; } [weakSelf.view configBlankPage:EaseBlankPageTypeView hasData:(data != nil) hasError:(error != nil) reloadButtonBlock:^(id sender) { [weakSelf sendRequest]; }]; }];}其中[self.view beginLoading]跟[weakSelf.view endLoading]就可以調(diào)用動畫效果；
補充：另一種是有很多不同的圖片組成的動畫效果，可以用每一張圖片然后FOR遍歷組成出動作效果；
//設(shè)置普通狀態(tài)的動畫圖片 NSMutableArray *idleImages = [NSMutableArray array]; for (NSUInteger i = 1; i<=60; ++i) { UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"dropdown_anim__000%zd",i]]; [idleImages addObject:image]; [idleImages addObject:image]; }以上內(nèi)容是本文通過IOS等待時動畫效果的實現(xiàn)，希望對大家有所幫助。
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