那些遇到过的问题

使用UIPinchGestureRecognizer在单向方向上缩放uiviews

Vir*_*raj 6 iphone objective-c ipad uigesturerecognizer ios

我想知道我们如何单独使用单一(x或y)方向UIPinchGestureRecognizer进行缩放UIView.比如,如果用户仅在单个方向(水平)上以捏合手势移动他的两个手指,则仅uiview的宽度应该增加/减小,并且如果手指仅垂直移动,则高度应该改变.如果手指沿对角线移动,则uiview的高度和宽度都应增加/减少.我看过Apple的MoveMe示例代码.

UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(scalePiece:)];
[pinchGesture setDelegate:self];
[piece addGestureRecognizer:pinchGesture];
[pinchGesture release];
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比例片:

- (void)scalePiece:(UIPinchGestureRecognizer *)gestureRecognizer
{
    UIView *piece = (UIView *) [gestureRecognizer view];
    NSLog(@"scalePiece enter");
    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan){
          NSLog(@"inside if");
          lastTouchPosition = [gestureRecognizer locationInView:piece];
    } 
    else if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged){
          NSLog(@"inside else");
          CGPoint currentTouchLocation = [gestureRecognizer locationInView:piece];
          NSLog(@"currentTouchLocation = %@ and lastTouchPosition= %@",NSStringFromCGPoint(currentTouchLocation), NSStringFromCGPoint(lastTouchPosition));
          CGPoint deltaMove = [self calculatePointDistancewithPoint1:currentTouchLocation andPoint2:lastTouchPosition];
          NSLog(@"deltaMove = %@",NSStringFromCGPoint(deltaMove));
          float distance = sqrt(deltaMove.x*deltaMove.x + deltaMove.y*deltaMove.y);
          NSLog(@"distance = %f",distance);
          float hScale = 1 - deltaMove.x/distance * (1-gestureRecognizer.scale);
          float vScale = 1 - deltaMove.y/distance * (1-gestureRecognizer.scale);
          if (distance == 0) {
                     hScale = 1;
                     vScale = 1;
          }
          NSLog(@"[gestureRecognizer scale] = %f",[gestureRecognizer scale]);
          NSLog(@"hScale = %f and vScale = %f",hScale, vScale);
          piece.transform = CGAffineTransformScale([piece transform], hScale, vScale);
          [gestureRecognizer setScale:1];
          lastTouchPosition = currentTouchLocation;
    }
    NSLog(@"scalePiece exit");
}
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计算距离:

- (CGPoint) calculatePointDistancewithPoint1:(CGPoint)point1 andPoint2:(CGPoint) point2 {
    return CGPointMake(point2.x - point1.x, point2.y - point1.y);
}
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这是当我试图捏出(放大)视图时仅在垂直方向上移动手指时的日志输出.元素的高度不会增加.

2011-07-21 13:06:56.245 New[8169:707] scalePiece enter
2011-07-21 13:06:56.248 New[8169:707] inside if
2011-07-21 13:06:56.251 New[8169:707] scalePiece exit
2011-07-21 13:06:56.259 New[8169:707] scalePiece enter
2011-07-21 13:06:56.262 New[8169:707] inside else
2011-07-21 13:06:56.264 New[8169:707] currentTouchLocation = {88, 87} and lastTouchPosition= {87, 86}
2011-07-21 13:06:56.265 New[8169:707] deltaMove = {-1, -1}
2011-07-21 13:06:56.267 New[8169:707] distance = 1.414214
2011-07-21 13:06:56.268 New[8169:707] [gestureRecognizer scale] = 1.102590
2011-07-21 13:06:56.271 New[8169:707] hScale = 0.927458 and vScale = 0.927458
2011-07-21 13:06:56.272 New[8169:707] scalePiece exit
2011-07-21 13:06:56.281 New[8169:707] scalePiece enter
2011-07-21 13:06:56.283 New[8169:707] inside else
2011-07-21 13:06:56.284 New[8169:707] currentTouchLocation = {87, 89} and lastTouchPosition= {88, 87}
2011-07-21 13:06:56.286 New[8169:707] deltaMove = {1, -2}
2011-07-21 13:06:56.287 New[8169:707] distance = 2.236068
2011-07-21 13:06:56.296 New[8169:707] [gestureRecognizer scale] = 1.096172
2011-07-21 13:06:56.298 New[8169:707] hScale = 1.043009 and vScale = 0.913981
2011-07-21 13:06:56.299 New[8169:707] scalePiece exit
2011-07-21 13:06:56.302 New[8169:707] scalePiece enter
2011-07-21 13:06:56.303 New[8169:707] inside else
2011-07-21 13:06:56.305 New[8169:707] currentTouchLocation = {88, 89} and lastTouchPosition= {87, 89}
2011-07-21 13:06:56.309 New[8169:707] deltaMove = {-1, 0}
2011-07-21 13:06:56.311 New[8169:707] distance = 1.000000
2011-07-21 13:06:56.313 New[8169:707] [gestureRecognizer scale] = 1.066320
2011-07-21 13:06:56.314 New[8169:707] hScale = 0.933680 and vScale = 1.000000
2011-07-21 13:06:56.316 New[8169:707] scalePiece exit
2011-07-21 13:06:56.318 New[8169:707] scalePiece enter
2011-07-21 13:06:56.320 New[8169:707] inside else
2011-07-21 13:06:56.329 New[8169:707] currentTouchLocation = {88, 90} and lastTouchPosition= {88, 89}
2011-07-21 13:06:56.331 New[8169:707] deltaMove = {0, -1}
2011-07-21 13:06:56.333 New[8169:707] distance = 1.000000
2011-07-21 13:06:56.334 New[8169:707] [gestureRecognizer scale] = 1.061696
2011-07-21 13:06:56.335 New[8169:707] hScale = 1.000000 and vScale = 0.938304
2011-07-21 13:06:56.338 New[8169:707] scalePiece exit
2011-07-21 13:06:56.343 New[8169:707] scalePiece enter
2011-07-21 13:06:56.346 New[8169:707] inside else
2011-07-21 13:06:56.347 New[8169:707] currentTouchLocation = {88, 92} and lastTouchPosition= {88, 90}
2011-07-21 13:06:56.349 New[8169:707] deltaMove = {0, -2}
2011-07-21 13:06:56.350 New[8169:707] distance = 2.000000
2011-07-21 13:06:56.351 New[8169:707] [gestureRecognizer scale] = 1.096869
2011-07-21 13:06:56.353 New[8169:707] hScale = 1.000000 and vScale = 0.903131
2011-07-21 13:06:56.362 New[8169:707] scalePiece exit
2011-07-21 13:06:56.366 New[8169:707] scalePiece enter
2011-07-21 13:06:56.370 New[8169:707] inside else
2011-07-21 13:06:56.373 New[8169:707] currentTouchLocation = {88, 92} and lastTouchPosition= {88, 92}
2011-07-21 13:06:56.376 New[8169:707] deltaMove = {0, 0}
2011-07-21 13:06:56.380 New[8169:707] distance = 0.000000
2011-07-21 13:06:56.383 New[8169:707] [gestureRecognizer scale] = 1.035330
2011-07-21 13:06:56.387 New[8169:707] hScale = 1.000000 and vScale = 1.000000
2011-07-21 13:06:56.389 New[8169:707] scalePiece exit
2011-07-21 13:06:56.393 New[8169:707] scalePiece enter
2011-07-21 13:06:56.397 New[8169:707] inside else
2011-07-21 13:06:56.399 New[8169:707] currentTouchLocation = {88, 93} and lastTouchPosition= {88, 92}
2011-07-21 13:06:56.403 New[8169:707] deltaMove = {0, -1}
2011-07-21 13:06:56.406 New[8169:707] distance = 1.000000
2011-07-21 13:06:56.409 New[8169:707] [gestureRecognizer scale] = 1.042659
2011-07-21 13:06:56.412 New[8169:707] hScale = 1.000000 and vScale = 0.957341
2011-07-21 13:06:56.414 New[8169:707] scalePiece exit
2011-07-21 13:06:56.419 New[8169:707] scalePiece enter
2011-07-21 13:06:56.422 New[8169:707] inside else
2011-07-21 13:06:56.425 New[8169:707] currentTouchLocation = {88, 92} and lastTouchPosition= {88, 93}
2011-07-21 13:06:56.427 New[8169:707] deltaMove = {0, 1}
2011-07-21 13:06:56.430 New[8169:707] distance = 1.000000
2011-07-21 13:06:56.432 New[8169:707] [gestureRecognizer scale] = 1.024549
2011-07-21 13:06:56.436 New[8169:707] hScale = 1.000000 and vScale = 1.024549
2011-07-21 13:06:56.439 New[8169:707] scalePiece exit
2011-07-21 13:06:56.442 New[8169:707] scalePiece enter
2011-07-21 13:06:56.447 New[8169:707] inside else
2011-07-21 13:06:56.450 New[8169:707] currentTouchLocation = {88, 92} and lastTouchPosition= {88, 92}
2011-07-21 13:06:56.453 New[8169:707] deltaMove = {0, 0}
2011-07-21 13:06:56.455 New[8169:707] distance = 0.000000
2011-07-21 13:06:56.458 New[8169:707] [gestureRecognizer scale] = 1.007702
2011-07-21 13:06:56.460 New[8169:707] hScale = 1.000000 and vScale = 1.000000
2011-07-21 13:06:56.464 New[8169:707] scalePiece exit
2011-07-21 13:06:56.501 New[8169:707] scalePiece enter
2011-07-21 13:06:56.504 New[8169:707] inside else
2011-07-21 13:06:56.507 New[8169:707] currentTouchLocation = {89, 92} and lastTouchPosition= {88, 92}
2011-07-21 13:06:56.509 New[8169:707] deltaMove = {-1, 0}
2011-07-21 13:06:56.510 New[8169:707] distance = 1.000000
2011-07-21 13:06:56.511 New[8169:707] [gestureRecognizer scale] = 1.000283
2011-07-21 13:06:56.513 New[8169:707] hScale = 0.999717 and vScale = 1.000000
2011-07-21 13:06:56.517 New[8169:707] scalePiece exit
2011-07-21 13:06:56.566 New[8169:707] scalePiece enter
2011-07-21 13:06:56.570 New[8169:707] inside else
2011-07-21 13:06:56.572 New[8169:707] currentTouchLocation = {89, 91} and lastTouchPosition= {89, 92}
2011-07-21 13:06:56.573 New[8169:707] deltaMove = {0, 1}
2011-07-21 13:06:56.575 New[8169:707] distance = 1.000000
2011-07-21 13:06:56.576 New[8169:707] [gestureRecognizer scale] = 1.008267
2011-07-21 13:06:56.579 New[8169:707] hScale = 1.000000 and vScale = 1.008267
2011-07-21 13:06:56.582 New[8169:707] scalePiece exit
2011-07-21 13:06:56.585 New[8169:707] scalePiece enter
2011-07-21 13:06:56.586 New[8169:707] inside else
2011-07-21 13:06:56.588 New[8169:707] currentTouchLocation = {89, 91} and lastTouchPosition= {89, 91}
2011-07-21 13:06:56.589 New[8169:707] deltaMove = {0, 0}
2011-07-21 13:06:56.591 New[8169:707] distance = 0.000000
2011-07-21 13:06:56.597 New[8169:707] [gestureRecognizer scale] = 1.000000
2011-07-21 13:06:56.599 New[8169:707] hScale = 1.000000 and vScale = 1.000000
2011-07-21 13:06:56.600 New[8169:707] scalePiece exit
2011-07-21 13:06:56.603 New[8169:707] scalePiece enter
2011-07-21 13:06:56.604 New[8169:707] inside else
2011-07-21 13:06:56.606 New[8169:707] currentTouchLocation = {89, 182} and lastTouchPosition= {89, 91}
2011-07-21 13:06:56.607 New[8169:707] deltaMove = {0, -91}
2011-07-21 13:06:56.617 New[8169:707] distance = 91.000000
2011-07-21 13:06:56.620 New[8169:707] [gestureRecognizer scale] = 1.000000
2011-07-21 13:06:56.623 New[8169:707] hScale = 1.000000 and vScale = 1.000000
2011-07-21 13:06:56.626 New[8169:707] scalePiece exit
2011-07-21 13:06:56.630 New[8169:707] scalePiece enter
2011-07-21 13:06:56.632 New[8169:707] scalePiece exit
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ser*_*gio 8

如果我正确理解了您的问题,那么您的目标是沿水平轴和垂直轴进行非比例缩放.在这种情况下,事情归结为提供你的仿射变换:

  piece.transform = CGAffineTransformScale([piece transform], hScale, vScale);
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具有不同的缩放因子.

计算它们的一种方法如下:

  1. 在你的班级定义一个ivar来存储lastTouchPosition;

  2. 在您的手势处理程序中,您将执行以下操作:

    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan){

   lastTouchPosition = [gestureRecognize locationInView:yourViewHere];
   hScale = 1;
   vScale = 1;

} else if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged){

   CGPoint currentTouchLocation = [gestureRecognize locationInView:yourViewHere];
   CGPoint deltaMove = CGPointDistance(currentTouchLocation, lastTouchPosition);
   float distance = sqrt(deltaMove.x*deltaMove.x + deltaMove.y*deltaMove.y);
   hScale -= abs(deltaMove.x)/distance * (1-gestureRecognizer.scale);
   vScale -= abs(deltaMove.y)/distance * (1-gestureRecognizer.scale);
   piece.transform = CGAffineTransformScale([piece transform], hScale, vScale);
   [gestureRecognizer setScale:1];

   lastTouchPosition = currentTouchLocation;
}
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另一种方法是:

    if ([gestureRecognizer state] == UIGestureRecognizerStateBegan){

       lastTouchPosition = [gestureRecognize locationInView:yourViewHere];

    } else if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged){

       CGPoint currentTouchLocation = [gestureRecognize locationInView:yourViewHere];
       CGPoint deltaMove = CGPointDistance(currentTouchLocation, lastTouchPosition);
       float distance = sqrt(deltaMove.x*deltaMove.x + deltaMove.y*deltaMove.y);
       float hScale = 1 - abs(deltaMove.x)/distance * (1-gestureRecognizer.scale);
       float vScale = 1 - abs(deltaMove.y)/distance * (1-gestureRecognizer.scale);
       piece.transform = CGAffineTransformScale([piece transform], hScale, vScale);

       lastTouchPosition = currentTouchLocation;
    }
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这将不会在每次迭代时存储当前值hFloat,vFloat而是依赖于gestureRecognizer将累积整体规模变化的事实.它执行"绝对"计算,而第一个实现执行"相对"计算.

请注意,您还需要定义CGPointDistance计算两个触摸之间的距离,并选择要用于计算距离(yourViewHere)的视图.

编辑:

CGPoint CGPointDistance(CGPoint point1, CGPoint point2)
{
    return = CGPointMake(point2.x - point1.x, point2.y - point1.y);
};
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EDIT2:关于计算缩放的公式

这个想法是计算比例因子的变化,并根据它们的相对变化将其应用于两个方向(x和y).

  1. 比例因子delta是:1-gestureRecognizer.scale;

  2. delta是乘以一个因子,以便它与水平轴或垂直轴的位移成比例; 当位移为零时,三角尺度也为零; 当位移沿两个轴线相等时,刻度差值沿两个轴线也相等; 我决定除以distance,但还有其他可能性(比如除以两个deltaMoves的总和或deltaMoves的最大值等).

  3. 最后从元素的当前比例中减去调整后的增量.

Ana*_*har 5

今天我面临同样的问题,我发现了一个简单而简短的方法

- (IBAction)handlePinch:(UIPinchGestureRecognizer *)recognizer
{
  recognizer.view.transform = CGAffineTransformScale(recognizer.view.transform, recognizer.scale,1);
  recognizer.scale = 1;
}
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