0

我有一个我正在尝试旋转的圆形图像，这样黄色和黑色的条纹圆圈就会停留在用户的手指下方并在两个方向上旋转。到目前为止我有这个：

- (void)handleJogShuttle:(UIPanGestureRecognizer *)recognizer {

    UIView *shuttle = [recognizer view];

    if ([recognizer state] == UIGestureRecognizerStateBegan ||
        [recognizer state] == UIGestureRecognizerStateChanged) {

        [recognizer view].transform = CGAffineTransformRotate([[recognizer view] transform],M_PI / 20.0f);
        [recognizer setTranslation:CGPointZero inView:[shuttle superview]];
    }
}

此外，目前，最轻微的移动都会导致视图旋转一整圈，这显然是不希望的。

4

2 回答 2

0 
#import "RotationTestViewController.h"

@interface RotationTestViewController()
-(void)transformSpinnerwithTouches:(UITouch *)touchLocation;
-(CGPoint)vectorFromPoint:(CGPoint)firstPoint toPoint:(CGPoint)secondPoint;
-(void)animateView:(UIView *)theView toPosition:(CGAffineTransform) newTransform;
@end
@implementation RotationTestViewController

- (void)viewDidLoad {
[super viewDidLoad];}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    for (UITouch *touch in touches)
    {
        // Send to the dispatch method, which will make sure the appropriate subview is acted upon
        //    currentTouch=touch;
    }
}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    for (UITouch *touch in touches){
        // Sends to the dispatch method, which will make sure the appropriate subview is acted upon
    }
}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch=[[event allTouches]anyObject];
    if (touch.view==Spinner)
    {
        [self transformSpinnerwithTouches:touch];
    }
}

-(void)transformSpinnerwithTouches:(UITouch *)touchLocation
{
    CGPoint touchLocationpoint = [touchLocation locationInView:self.view];
    CGPoint PrevioustouchLocationpoint = [touchLocation previousLocationInView:self.view];
    //origin is the respective piont from that i gonna measure the angle of the current position with respective to previous position ....
    CGPoint origin;
    origin.x=Spinner.center.x;
    origin.y=Spinner.center.y;
    CGPoint previousDifference = [self vectorFromPoint:origin toPoint:PrevioustouchLocationpoint];
    CGAffineTransform newTransform =CGAffineTransformScale(Spinner.transform, 1, 1);
    CGFloat previousRotation = atan2(previousDifference.y, previousDifference.x);
    CGPoint currentDifference = [self vectorFromPoint:origin toPoint:touchLocationpoint];
    CGFloat currentRotation = atan2(currentDifference.y, currentDifference.x);
    CGFloat newAngle = currentRotation- previousRotation;
    temp1=temp1+newAngle;
    NSLog(@"Angle:%F\n",(temp1*180)/M_PI);
    newTransform = CGAffineTransformRotate(newTransform, newAngle);
    [self animateView:Spinner toPosition:newTransform];
}

-(void)animateView:(UIView *)theView toPosition:(CGAffineTransform) newTransform
{
    [UIView setAnimationsEnabled:YES];
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationCurve:UIViewAnimationCurveLinear];
    [UIView setAnimationBeginsFromCurrentState:YES];
    [UIView setAnimationDuration:0.0750];
    Spinner.transform = newTransform;
    [UIView commitAnimations];
}

//-(CGFloat)distanceFromPoint:(CGPoint)fromPoint toPoint:(CGPoint)toPoint
//
//{
//float x = toPoint.x - fromPoint.x;
//float y = toPoint.y - fromPoint.y;
//return hypot(x, y);
//}

-(CGPoint)vectorFromPoint:(CGPoint)firstPoint toPoint:(CGPoint)secondPoint
{
    CGFloat x = secondPoint.x - firstPoint.x;
    CGFloat y = secondPoint.y - firstPoint.y;
    CGPoint result = CGPointMake(x, y);
    //NSLog(@"%f %f",x,y);
    return result;
}

-(void) dealloc
{
    [Spinner release];
    [super dealloc];
}
于 2011-01-10T09:16:47.530 回答
0

我怀疑这种方法被称为很多。尝试使用NSLog并检查它做了多少次。无论如何，您没有正确计算角度，您可以尝试使用

-(CGPoint)translationInView:(UIView *)view

从识别器计算正确的旋转角度。

于 2010-07-30T13:42:31.233 回答