本文實例介紹了iOS實現左右拖動抽屜效果,具體內容如下
利用了觸摸事件滑動 touchesMoved: 來觸發左右視圖的出現和消失 利用loadView方法中添加view 在self.view載入前就把 左右中View都設置好frame 每一個方法都由單獨的功能。
#import "DarwViewController.h" @interface DarwViewController () @property (nonatomic, weak) UIView *leftView; @property (nonatomic, weak) UIView *rightView; @property (nonatomic, weak) UIView *mainView; /** * 動畫是否進行 */ @property (nonatomic ,assign) BOOL animating; @end @implementation DarwViewController - (void)viewDidLoad { [super viewDidLoad]; } -(void)loadView { self.view = [[UIView alloc]initWithFrame:[UIScreen mainScreen].bounds]; //左邊view UIView *leftView = [[UIView alloc]initWithFrame:self.view.frame]; [self.view addSubview:leftView]; leftView.backgroundColor= [UIColor redColor]; self.leftView = leftView; //右邊View UIView *rightView = [[UIView alloc]initWithFrame:self.view.frame]; [self.view addSubview:rightView]; rightView.backgroundColor= [UIColor blueColor]; self.rightView = rightView; //主頁面 UIView *mainView = [[UIView alloc]initWithFrame:self.view.frame]; [self.view addSubview:mainView]; mainView.backgroundColor= [UIColor yellowColor]; self.mainView = mainView; //KVO監聽 [self.mainView addObserver:self forKeyPath:@"frame" options:NSKeyValueObservingOptionNew context:nil]; } /** * KVO回調方法 當mainView Frame值改變時觸發 * * @param keyPath <#keyPath description#> * @param object <#object description#> * @param change <#change description#> * @param context <#context description#> */ -(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context { if (self.animating) return; //如果mainView正在動畫 就不執行 if (self.mainView.frame.origin.x > 0 ) { //X > 0 就隱藏右邊View 顯示左邊View self.rightView.hidden = YES; self.leftView.hidden = NO; } else if (self.mainView.frame.origin.x < 0) { //X < 0 就隱藏左邊View 顯示右邊VIew self.leftView.hidden = YES; self.rightView.hidden = NO; } } #pragma mark -- 觸摸事件 -(void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event { //獲得觸摸對象 UITouch *touch = [touches anyObject]; //獲得當前觸摸點 CGPoint currentPoint = [touch locationInView:self.view]; //獲得上一個觸摸點 CGPoint previousPoint = [touch previousLocationInView:self.view]; //計算x方向的偏移量 CGFloat offsetX = currentPoint.x - previousPoint.x; // 根據x的偏移量計算y的偏移量 self.mainView.frame = [self rectWithOffsetX:offsetX]; } #define screenW [UIScreen mainScreen].bounds.size.width #define screenH [UIScreen mainScreen].bounds.size.height /** * 計算主視圖的frame * * @param offsetX x的偏移量 * * @return 偏移後新的frame */ - (CGRect ) rectWithOffsetX:(CGFloat )offsetX { //Y軸的偏移量 CGFloat offsetY = (screenH *1/5) * (offsetX/screenW); //比例 :(用於寬高的縮放) CGFloat scale = (screenH - offsetY *2) / screenH; if (self.mainView.frame.origin.x < 0 ) { //如果x是負數 及左邊View要顯示 //比例就要設為比1小 scale = 2 - scale; } //獲取當前mainView的frame CGRect frame = self.mainView.frame; //重新設置mainView的frame值 frame.size.width = frame.size.width *scale >screenW ? screenW : frame.size.width *scale; frame.size.height = frame.size.height *scale >screenH ? screenH :frame.size.height *scale; frame.origin.x += offsetX; frame.origin.y =(screenH - frame.size.height)*0.5; //返回偏移後新的frame return frame; } #define maxRightX (screenW *0.8) #define maxLeftX (-screenW *0.6) -(void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event { CGFloat targetX = 0; //如果松手的那一下 當前mainVIew的x大於屏幕的一半 if (self.mainView.frame.origin.x > screenW * 0.5) { //向右邊定位 targetX = maxRightX; } //如果松手的那一下 當前mainVIew的最大X值小於屏幕的一半 else if (CGRectGetMaxX(self.mainView.frame) < screenW *0.5) { //向左邊定位 targetX = maxLeftX; } //計算偏移量 CGFloat offsetX = targetX -self.mainView.frame.origin.x; self.animating = YES; [UIView animateWithDuration:0.4 animations:^{ if (targetX == 0) { //如果targetX==0 復位 self.mainView.frame = self.view.frame; } else { //如果targetX != 0 那就到指定位置 self.mainView.frame = [self rectWithOffsetX:offsetX]; } } completion:^(BOOL finished) { self.animating = NO; }]; } @end
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