爲什麼touchesbegan：在使用UIPinchGestureRecognizer之後永遠不會調用UIView？

我正在開發一個繪圖應用程序，讓用戶在它的superView（self.view）所查看的UIView（InsideView）上繪製UIbezierpath。我在0123View中使用傳統的繪圖代碼，例如touchesBegan:, touchesMoved:, touchesEnded:，我正在處理viewController類（這是InsideView的superView）內的縮放縮放代碼handlePinch:(UIPinchGestureRecognizer *)recognizer:。爲什麼touchesbegan：在使用UIPinchGestureRecognizer之後永遠不會調用UIView？

當我第一次繪製時，我可以在它後面進行縮放，但是當我首先進行縮放時，繪圖代碼（touchesBegan等）在UIPinchGestureRecognizer被觸發後不會被調用，並且它不會在InsideView上繪製任何東西。我究竟做錯了什麼？提前致謝。

//代碼在InsideView（這是一個UIView子類，是self.view子視圖）

- (id)initWithFrame:(CGRect)frame{    
       self = [super initWithFrame:frame]; 
       if (self) { 
          path = [UIBezierPath bezierPath]; 
          [path setLineWidth:7.0]; 
          pointsArray = [NSMutableArray array]; 
          finish = NO; 
          } 
        return self; 
} 
-(void)drawRect:(CGRect)rect{ 
         [[UIColor redColor] setStroke]; 
         [path stroke]; 
} 
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{ 

        UITouch *touch = [touches anyObject]; 
        CGPoint p = [touch locationInView:self]; 
        [path moveToPoint:p]; 
        [pointsArray addObject:[NSValue valueWithCGPoint:p]]; 
} 
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{ 

        UITouch *touch = [touches anyObject]; 
        CGPoint p = [touch locationInView:self]; 
        [path addLineToPoint:p]; 
        [self setNeedsDisplay]; 
        [pointsArray addObject:[NSValue valueWithCGPoint:p]]; 
} 
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{ 

        [path closePath]; 

        //Smoothing the path. 
        path.miterLimit=-10; 
        [self setNeedsDisplay]; 
        finish = YES; 
} 

//Code in the viewController (InsideView's superView) 
- (void)viewDidLoad { 
     [super viewDidLoad]; 
     InsideView* sV = [InsideView new]; 
     [sV setFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)]; 
     [self.view addSubview:sV]; 

     //Pinch 
     UIPinchGestureRecognizer*pinch = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(handlePinch:)]; 
     pinch.delegate =self; 
     [sV addGestureRecognizer:pinch]; 
} 
- (void)handlePinch:(UIPinchGestureRecognizer *)recognizer{ 

     if ([recognizer numberOfTouches] < 2) 
      return; 
     if (recognizer.state == UIGestureRecognizerStateBegan) { 
      lastScale = 1.0; 
      lastPoint = [recognizer locationInView:self.view]; 
     } 
     // Scale 
     CGFloat scale = 1.0 - (lastScale - recognizer.scale); 
     [sV.layer setAffineTransform: 
     CGAffineTransformScale([sV.layer affineTransform], 
           scale, 
           scale)]; 
     lastScale = recognizer.scale; 
     // Translate 
     CGPoint point = [recognizer locationInView:self.view]; 

     [sV.layer setAffineTransform: 
     CGAffineTransformTranslate([sV.layer affineTransform], 
            point.x - lastPoint.x, 
            point.y - lastPoint.y)]; 
     lastPoint = [recognizer locationInView:self.view]; 
} 
-(void)handlePinchWithGestureRecognizer:(UIPinchGestureRecognizer *)pinchGestureRecognizer{ 
     sV.transform = CGAffineTransformScale(sV.transform, pinchGestureRecognizer.scale, pinchGestureRecognizer.scale); 
     pinchGestureRecognizer.scale = 1.0; 
} 
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{ 
     return YES; 
}

來源

2016-08-22 Reza.Ab

嘗試在touches中調用超級方法。當你的手勢識別器觸發時（也只是一個猜測），你也可以設置完成爲true – deadbeef

我建議你刪除這條代碼行'pinch.delegate = self;'，因爲它不是必要的，也許這就解決了你的問題 – ddb

你可以試試從drawRect刪除捏手勢設置，並將其移動到initWithFrame，使它只發生一次？每次在drawRect上設置pinch也是很荒謬的。 – satheeshwaran

我已經開發了一個UIViewController，我同時使用他們沒有任何問題，S也許解決方案可能是將此邏輯從UIView移動到UIViewController。因此，在viewDidLoad你可以touchesBegan:withEvent:定義捏識別這樣

UIPinchGestureRecognizer* pinch = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(handlePinch:)]; 
[self.view addGestureRecognizer:pinch];

當然也是方法 handlePinch:應該被移到 UIViewController的

，在一起， touchesMoved:withEvent:，touchesEnded:withEvent:方法

你應該在這些改變什麼方法是，你應該改變

self

到

self.yourSpecificCurrentUIView

來源

2016-08-22 12:53:10 ddb

感謝您的建議，我在ViewController裏面提供了捏合處理代碼，這是我的圖紙視圖的超級視圖，並且我在圖紙視圖（這是一個uiview子類）中提供了圖形代碼。它確實解決了這個問題。 –

爲什麼touchesbegan：在使用UIPinchGestureRecognizer之後永遠不會調用UIView？

回答

相關問題