在 iPhone 中使用 UIPanGesture 旋转 UIView 的框架增加减少

Question

我创建了一个 UIView，应用 UIPanGestureRecognizer 用一根手指旋转，也用一根手指增加和减少它的框架。

• 旋转视图放在 UIView 的左下角。
• 调整 UIView 右下角的视图大小。

让我写下它的一些代码行。

//Rotate Apply with Pan Gesture 
    panRotateGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(rotateViewPanGesture:)];
    [rotateView addGestureRecognizer:panRotateGesture];

    //Resize View Apply with Pan Gesture 
    panResizeGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(resizeTranslate:)];
    [resizeView addGestureRecognizer:panResizeGesture];

    [panRotateGesture requireGestureRecognizerToFail:panResizeGesture]; 

这是用一根手指用 UIPanGesture 调整视图大小的方法。

-(void)resizeTranslate:(UIPanGestureRecognizer *)recognizer
{
    if ([recognizer state]== UIGestureRecognizerStateBegan) 
    {
        prevPoint = [recognizer locationInView:self.superview];
        [self setNeedsDisplay];
    }
    else if ([recognizer state] == UIGestureRecognizerStateChanged)
    {
        if (self.frame.size.width < kFixW)
        {
            self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, kFixW, self.frame.size.height);
        }

        if(self.frame.size.height < kFixH)
        {
            self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, self.frame.size.width, kFixH);
        }

        CGPoint point = [recognizer locationInView:self.superview];
        float wChange = 0.0, hChange = 0.0;

        wChange = (point.x - prevPoint.x); //Slow down increment
        hChange = (point.y - prevPoint.y); //Slow down increment 


        self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, self.frame.size.width + (wChange), self.frame.size.height + (hChange));
        NSLog(@"self.frame : %@",NSStringFromCGRect(self.frame));

        prevPoint = [recognizer locationInView:self.superview];

        [self setNeedsDisplay];
    }
    else if ([recognizer state] == UIGestureRecognizerStateEnded)
    {

        prevPoint = [recognizer locationInView:self.superview];
        [self setNeedsDisplay];
    }
}

如果用一根手指用 UIPanGesture 旋转 UIView

-(void)rotateViewPanGesture:(UIPanGestureRecognizer *)recognizer
{
    if ([recognizer state] == UIGestureRecognizerStateBegan) 
    {
        deltaAngle = atan2([recognizer locationInView:self].y-self.center.y, [recognizer locationInView:self].x-self.center.x);
        startTransform = self.transform;
    }
    else if ([recognizer state] == UIGestureRecognizerStateChanged) 
    {
        float ang = atan2([recognizer locationInView:self.superview].y - self.center.y, [recognizer locationInView:self.superview].x - self.center.x);
        float angleDiff = deltaAngle - ang;
        self.transform = CGAffineTransformMakeRotation(-angleDiff);
        [self setNeedsDisplay];
    }
    else if ([recognizer state] == UIGestureRecognizerStateEnded)
    {
        float ang = atan2([recognizer locationInView:self.superview].y - self.center.y, [recognizer locationInView:self.superview].x - self.center.x);
        deltaAngle = atan2([recognizer locationInView:self].y-self.center.y, [recognizer locationInView:self].x-self.center.x);
        startTransform = self.transform;
        [self setNeedsDisplay];
    }
}

现在的问题是， 调整大小和旋转手势都可以正常工作。

当我使用 panResizeGesture 调整视图大小时，它可以正常工作，但是如果我应用一次 panRotateGesture 并且想要应用 panResizeGesture 它会超出屏幕并且无法正常工作。

请有任何解决此问题的想法。

非常感谢。

Answer 1

documentation 明确表示：

**如果变换属性不是恒等变换，则该属性的值是未定义的，因此应该被忽略。

如果transform 属性包含非身份转换，则frame 属性的值未定义且不应修改。在这种情况下，您可以使用 center 属性重新定位视图并使用 bounds 属性调整大小。**

所以，只需在 rotateViewPanGesture 方法中将 self.frame 改为 self.bounds

例如

        self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, self.frame.size.width, kFixH);

到：

        self.bounds = CGRectMake(self.bounds.origin.x, self.bounds.origin.y, self.bounds.size.width, kFixH);

您的代码将完美运行。

更新

我附上了使用您的代码的示例项目。你可以使用这个代码 Answer

Answer 2

我知道这有点晚了，所以也许您已经想通了，但是您的问题在于 locationInView: 部分代码。当您确实想要计算超级视图的 locationInView 时，您正在尝试计算您尝试旋转的实际视图的 locationInView。

-(void)rotateViewPanGesture:(UIPanGestureRecognizer *)recognizer{
if ([recognizer state] == UIGestureRecognizerStateBegan) 
{
    deltaAngle = atan2([recognizer locationInView:self.superview].y-self.center.y, [recognizer locationInView:self.superview].x-self.center.x); //here change it to self.superview
    startTransform = self.transform;
}
else if ([recognizer state] == UIGestureRecognizerStateChanged) 
{
    float ang = atan2([recognizer locationInView:self.superview].y - self.center.y, [recognizer locationInView:self.superview].x - self.center.x);
    float angleDiff = deltaAngle - ang;
    self.transform = CGAffineTransformMakeRotation(-angleDiff);
    [self setNeedsDisplay];
}
else if ([recognizer state] == UIGestureRecognizerStateEnded)
{
    float ang = atan2([recognizer locationInView:self.superview].y - self.center.y, [recognizer locationInView:self.superview].x - self.center.x);
    deltaAngle = atan2([recognizer locationInView:self.superview].y-self.center.y, [recognizer locationInView:self.superview].x-self.center.x); //here change it to locationInView:self.superview
    startTransform = self.transform;
    [self setNeedsDisplay];
}}