iphone - iPhone 动画 - 将视图移动一圈

Question

有没有一种方法可以在不使用视图动画旋转的情况下围绕中心点移动视图？

   一个

ACA

   一个

Answer 1

    #import <QuartzCore/QuartzCore.h>
    #define degreesToRadians(deg) (deg / 180.0 * M_PI)

手动：

-(CGPoint)setPointToAngle:(int)angle center:(CGPoint)centerPoint radius:(double)radius
 {
    return CGPointMake(radius*cos(degreesToRadians(angle)) + centerPoint.x, radius*sin(degreesToRadians(angle)) + centerPoint.y);
 }

动画是这样的：

    int angle = 0; // start angle position 0-360 deg
    CGPoint center = self.view.center;
    CGPoint start = [self setPointToAngle:angle center:center radius:radius]; //point for start moving
    CGMutablePathRef path = CGPathCreateMutable();
    CGPathMoveToPoint(path, NULL, start.x, start.y);

    for(int a =0;a<4;a++) //set path points for 90, 180, 270,360 deg form begining angle
    {
        angle+=45;
        expPoint = [self setPointToAngle:angle center:center radius:expRadius];
        angle+=45;
        start = [self setPointToAngle:angle center:center radius:radius];
        CGPathAddQuadCurveToPoint(path, NULL,expPoint.x, expPoint.y, start.x, start.y);
    }

    CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
    pathAnimation.removedOnCompletion = NO;
    pathAnimation.path = path;
    [pathAnimation setCalculationMode:kCAAnimationCubic];
    [pathAnimation setFillMode:kCAFillModeForwards];
    pathAnimation.duration = 14.0; 

    [MY_VIEW.layer addAnimation:pathAnimation forKey:nil];

也看看

CGPathAddQuadCurveToPoint, 
CGPathAddCurveToPoint, 
CGPathAddArcToPoint, 
CGPathAddArc 

和别的

Answer 2

将动画线程放入并在每一帧手动移动它并不是什么大不了的事，这就是我所采用的。