iOS UIPinchGestureRecognizer在UIGestureRecognizerStateEnded狀態下獲取與未知源的偏移

Question

我有一個具有自定義drawRect（）方法的UIView，用於某些繪圖。

我使用UIPinchGestureRecognizer實現縮放效果。

這是操作方法：

- (IBAction)handlePinch:(UIPinchGestureRecognizer *)recognizer 
{ 
    //NSLog(@"Pinch gesture recognized"); 

    CGPoint touchOrigin = [recognizer locationInView:self]; 
    _currentScaleOrigin = touchOrigin; 

    if (recognizer.state == UIGestureRecognizerStateEnded) 
    { 
     NSLog(@"%16@ x = %f, y = %f", @"Pinch end:", touchOrigin.x, touchOrigin.y); 
     return; 
    } 

    if (recognizer.state == UIGestureRecognizerStateChanged) 
    { 
     //NSLog(@"scale = %f", recognizer.scale); 
     NSLog(@"%16@ x = %f, y = %f", @"Pinch origin:", touchOrigin.x, touchOrigin.y); 

     // scale has at start a value of 1.0 and increases as fingers moves away from each other 
     _currentScaleLevel += recognizer.scale - 1; 
     [self setNeedsDisplay]; // call drawRect for redrawing at current scale level 
    } 

    recognizer.scale = 1; 

} 

當接收UIGestureRecognizerStateEnded消息我得到一些奇怪的偏移座標：

Pinch origin: x = 358.000000, y = 630.000000 

Pinch origin: x = 355.000000, y = 627.000000 

Pinch origin: x = 353.000000, y = 625.000000 

Pinch origin: x = 351.000000, y = 624.000000 

Pinch origin: x = 351.000000, y = 623.000000 

Pinch origin: x = 350.000000, y = 622.000000 

Pinch origin: x = 349.000000, y = 622.000000 

Pinch origin: x = 349.000000, y = 622.000000 

Pinch end: x = 315.000000, y = 750.000000 

...和翻譯免費:)我不需要。 我不知道翻譯來自哪裏。

如何禁用此翻譯？

Answer 1

解決了它。

當收到UIGestureRecognizerStateEnded我分配兩個手指的最後一個點到我的_currentScaleOrigin這是執行縮放變換。

我不知道UIPinchGestureRecognizer返回屏幕上最後一個手指位置的CGPoint。

這裏是整個方法的代碼：

- (IBAction)handlePinch:(UIPinchGestureRecognizer *)recognizer 
{ 
#if 1 
    static CGPoint point_0; 
    static CGPoint point_1; 
    if ([recognizer numberOfTouches] > 1) 
    { 
     point_0 = [recognizer locationOfTouch:0 inView:self]; 
     point_1 = [recognizer locationOfTouch:1 inView:self]; 
     NSLog(@"pinch loc 0: (%f, %f)", point_0.x , point_0.y); 
     NSLog(@"pinch loc 1: (%f, %f)", point_1.x , point_1.y); 
    } else if ([recognizer numberOfTouches] == 1) { 
     point_0 = [recognizer locationOfTouch:0 inView:self]; 
     NSLog(@"pinch loc 0: (%f, %f)", point_0.x , point_0.y); 
    } 
#endif 

    switch (recognizer.state) 
    { 
     case UIGestureRecognizerStateBegan: 
     { 
      CGPoint pointBegin = [recognizer locationInView:self]; 
      NSLog(@"%16@ x = %f, y = %f", @"Pinch start:", pointBegin.x, pointBegin.y); 
     } break; 
     case UIGestureRecognizerStateChanged: 
     { 
      _currentScaleOrigin = [recognizer locationInView:self]; 

      //NSLog(@"scale = %f", recognizer.scale); 
      NSLog(@"%16@ x = %f, y = %f", @"Pinch origin:", _currentScaleOrigin.x, _currentScaleOrigin.y); 

      // scale has at start a value of 1.0 and increases as fingers moves away from each other 
      _currentScaleLevel += recognizer.scale - 1; 
      // call drawRect for redrawing at current scale level 
      [self setNeedsDisplay]; 
     } break; 
     case UIGestureRecognizerStateEnded: 
     { 
      CGPoint pointEnded = [recognizer locationInView:self]; 
      NSLog(@"%16@ x = %f, y = %f", @"Pinch end:", pointEnded.x, pointEnded.y); 
      //return; 
     } break; 
     default : 
     { 
      NSLog(@"other state"); 
     } 
    } 

    recognizer.scale = 1; 
}