iPhone一指缩放手势识别器

Question

我想处理视图的缩放和旋转，在该视图中有一个角。我找到了一个关于旋转的教程。https://github.com/kirbyt/KTOneFingerRotationGestureRecognizer

它使用atan2f函数自定义UIGesturRecognizer进行旋转。但是我找不到缩放的方法。谁能告诉我缩放的数学函数是类似的，或者有什么教程帮助吗?

Answer 1

找到下面的教程缩放图像。

https://github.com/ardalahmet/SSPhotoCropperViewController

https://github.com/iosdeveloper/ImageCropper

下载

Answer 2

请尝试这段代码，您将能够旋转，缩放和移动任何对象:

https://github.com/erica/iphone - 3.0 -食谱-/tree/master/c08 gestures/14 resize%20and%20rotate/

Answer 3

-(void)oneFingerGesture:(UIPanGestureRecognizer *)识别器{if([识别器状态]== UIGestureRecognizerStateBegan){//旋转deltaAngle = atan2([recognizer locationInView:holderView.superview].y- holderview .center.)y，[识别器locationInView:holderView.superview].x-holderView.center.x);startTransform = holderView.transform;//调整prevPoint =[识别器locationInView:holderView.superview];[holderView setNeedsDisplay];

}
else if ([recognizer state] == UIGestureRecognizerStateChanged)
{
    //rotation
    float ang = atan2([recognizer locationInView:holderView.superview].y - holderView.center.y, [recognizer locationInView:holderView.superview].x - holderView.center.x);
    float angleDiff = deltaAngle - ang;
    holderView.transform = CGAffineTransformRotate(startTransform, -angleDiff);
    //resize
    CGPoint point = [recognizer locationInView:holderView.superview];
    float wChange = 0.0, hChange = 0.0, value=0.0;
    wChange = (point.x - prevPoint.x);
    hChange = (point.y - prevPoint.y);
    CGFloat radians = atan2f(holderView.transform.b, holderView.transform.a);
    CGFloat degrees = radians * (180 / M_PI);
    if (degrees<=0 && degrees>=-90) {
        value=wChange;
    }
    else if (degrees<=-90 && degrees>=-180){
        value=-hChange;
    }
    else if (degrees<=180 && degrees>=90){
        value=-wChange;
    }
    else if (degrees<=90 && degrees>=0){
        value=hChange;
    }
    holderView.bounds = CGRectMake(holderView.bounds.origin.x, holderView.bounds.origin.y, holderView.bounds.size.width + (value), holderView.bounds.size.height + (value));
    imageview.frame = CGRectMake(12, 12, holderView.bounds.size.width-24, holderView.bounds.size.height-27);
    View_marqueRotate.frame =CGRectMake(holderView.bounds.size.width-25, holderView.bounds.size.height-25, 25, 25);
    View_marqueClose.frame = CGRectMake(0, 0, 25, 25);
    prevPoint = [recognizer locationInView:holderView.superview];
    [holderView setNeedsDisplay];

}
else if ([recognizer state] == UIGestureRecognizerStateEnded)
{
    //rotation
    deltaAngle = atan2([recognizer locationInView:holderView.superview].y-holderView.center.y, [recognizer locationInView:holderView.superview].x-holderView.center.x);
    startTransform = holderView.transform;
    //resize
    prevPoint = [recognizer locationInView:holderView.superview];
    [holderView setNeedsDisplay];
}

}