在触摸的方向旋转的UIImageView动画(UIImageView rotation animat

我有具有箭头的图像一个的UIImageView。 当用户点击了UIView这个箭头应指向水龙头的方向维修器材的位置应该只是改变了变换。 我已经实现下面的代码。 但它不按预期工作。 我添加了一个屏幕截图。 在这个屏幕截图时，我触摸点左上的箭头方向应尽可能shown.But它是不会发生如此。

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

 UITouch *touch=[[event allTouches]anyObject];
 touchedPoint= [touch locationInView:touch.view];
 imageViews.transform = CGAffineTransformMakeRotation(DEGREES_TO_RADIANS(rangle11));
 previousTouchedPoint = touchedPoint ;
}

- (CGFloat) pointPairToBearingDegrees:(CGPoint)startingPoint secondPoint:(CGPoint) endingPoint
{

 CGPoint originPoint = CGPointMake(endingPoint.x - startingPoint.x, endingPoint.y - startingPoint.y); // get origin point to origin by subtracting end from start
   float bearingRadians = atan2f(originPoint.y, originPoint.x); // get bearing in radians
float bearingDegrees = bearingRadians * (180.0 / M_PI); // convert to degrees
bearingDegrees = (bearingDegrees > 0.0 ? bearingDegrees : (360.0 + bearingDegrees)); // correct discontinuity
return bearingDegrees;
}

Answer 1:

我想你想的箭头图像指向你在哪里都摸，我想这是我能想出。 我把图像视图用一个箭头指向上方（还没有尝试过其他任何位置开始，日志给出正确的角度）和抚触对不同位置它旋转和点触摸的位置。 希望它可以帮助（尝试了一些旧的数学:-)）

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

    UITouch *touch=[[event allTouches]anyObject];
    touchedPoint= [touch locationInView:touch.view];
    CGFloat angle = [self getAngle:touchedPoint];
    imageView.transform = CGAffineTransformMakeRotation(angle);

}

-(CGFloat) getAngle: (CGPoint) touchedPoints
{
    CGFloat x1 = imageView.center.x;
    CGFloat y1 = imageView.center.y;

    CGFloat x2 = touchedPoints.x;
    CGFloat y2 = touchedPoints.y;

    CGFloat x3 = x1;
    CGFloat y3 = y2;

    CGFloat oppSide = sqrtf(((x2-x3)*(x2-x3)) + ((y2-y3)*(y2-y3)));
    CGFloat adjSide = sqrtf(((x1-x3)*(x1-x3)) + ((y1-y3)*(y1-y3)));

    CGFloat angle = atanf(oppSide/adjSide);
    // Quadrant Identifiaction
    if(x2 < imageView.center.x)
    {
        angle = 0-angle;
    }


    if(y2 > imageView.center.y)
    {
        angle = M_PI/2 + (M_PI/2 -angle);
    }
     NSLog(@"Angle is %2f",angle*180/M_PI);
    return angle;

}

-anoop4real

Answer 2:

鉴于你告诉我，我认为这个问题是你是不是在重置您的转换touchesBegan 。 尝试将其更改为这样的事情，看看它是否效果更好：

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

 UITouch *touch=[[event allTouches]anyObject];
 touchedPoint= [touch locationInView:touch.view];
 imageViews.transform = CGAffineTransformIdentity;
 imageViews.transform = CGAffineTransformMakeRotation(DEGREES_TO_RADIANS(rangle11));
 previousTouchedPoint = touchedPoint ;
}

Answer 3:

您是否需要行至“删除中断”？ 似乎atan2f() +π到-π之间返回值。 会不会那些直接与工作CATransform3DMakeRotation()

Answer 4:

你需要的是一个箭头指向最后一个抽头点。 为了简化和测试，我已经使用了点触手势（但它是类似于touchBegan：withEvent :)。

在viewDidLoad方法，我注册所述手势：

UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapped:)];
[self.view addGestureRecognizer:tapGesture];
[tapGesture release];

呼吁每个抽头的方法：

- (void)tapped:(UITapGestureRecognizer *)gesture
{
    CGPoint imageCenter = mFlecheImageView.center;
    CGPoint tapPoint = [gesture locationInView:self.view];

    double deltaY = tapPoint.y - imageCenter.y;
    double deltaX = tapPoint.x - imageCenter.x;
    double angleInRadians = atan2(deltaY, deltaX) + M_PI_2;

    mFlecheImageView.transform = CGAffineTransformMakeRotation(angleInRadians);
}

一个关键是+ M_PI_2因为UIKit的坐标具有在左上角的原点（而在三角函数，我们使用了左下角）。

文章来源: UIImageView rotation animation in the touched direction