Question

我正在尝试围绕它的当前位置旋转对象，

CGAffineTransform trans =   CGAffineTransformMakeRotation(compass_heading );
trans = CGAffineTransformTranslate(trans, 0, 90);
sun_image.transform = trans;

但它没有效果， sun_image 不动！但是，如果我将其更改为此并在X轴上转换它会移动！这是什么意思？

CGAffineTransform trans =   CGAffineTransformMakeRotation(compass_heading );
trans = CGAffineTransformTranslate(trans, 90, 0);
sun_image.transform = trans;

Answer 1

以下是旋转对象的方法：

    CGFloat rotation = M_PI_2;

    CGAffineTransform currentTransform = sun_image.transform;
    CGAffineTransform newTransform = CGAffineTransformRotate(currentTransform,rotation);

    [sun_image setTransform:newTransform];

使用CGAffineTransformTranslate您可以移动对象，因此您必须使用CGAffineTransformRotate。

对于位置经理：

-(void) locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading
{     
     //set the anchorPoint as the lower right corner of the layer
     sun_image.layer.anchorPoint = CGPointMake(1, 1);

     [sun_image.layer setAffineTransform:CGAffineTransformMakeRotation(-1*newHeading.trueHeading*3.14159/180)];
}

Answer 2

我通常会为翻译转换执行此操作：

sun_image.transform = CGAffineTransformMakeTranslation(dx,dy);

Answer 3

首先将UIImageView的中心设置为您的视图中心属性，如下方..

yourImageView.center = self.view.center;

设置GestureRecognizer后如下...

    UIRotationGestureRecognizer *rotationRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotate:)];
    [rotationRecognizer setDelegate:self];
    [yourImageView addGestureRecognizer:rotationRecognizer];
    [rotationRecognizer release];

然后使用此波纹管方法旋转UIImageView

-(void)rotate:(id)sender 
{
    UIView *imgTempGest = [sender view];

    if([(UIRotationGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) 
    {
        lastRotation = 0.0;
        return;
    }
    CGFloat rotation = 0.0 - (lastRotation - [(UIRotationGestureRecognizer*)sender rotation]);

    CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
    CGAffineTransform newTransform = CGAffineTransformRotate(currentTransform,rotation);

    [[(UIRotationGestureRecognizer*)sender view] setTransform:newTransform];

    [imgTempGest setTransform:newTransform];

    lastRotation = [(UIRotationGestureRecognizer*)sender rotation];
}

将lastRotation的{{1}}变量视为下方...

CGFloat

改变不工作

3 个答案: