旋轉的UIImageView周圍任意點

我有圍繞其中心旋轉一個UIImageView：旋轉的UIImageView周圍任意點

imageHorizon.layer.anchorPoint = CGPointMake(0.5, 0.5); 
imageHorizon.transform = CGAffineTransformRotate(imageHorizon.transform, angleToRotate*(CGFloat)(M_PI/180));

有時我也在這個圖像移動到左或右，然後再旋轉。我希望始終將旋轉中心保持在同一點（實際上是超級視圖的中心）。我怎樣才能做到這一點？

歡呼聲，

來源

2011-07-29 Jan

您可以使圖像的另一視圖的子視圖，然後旋轉上海華來獲得這種效果。另一種方法是設置anchorPoint屬性，如docs中所述。

來源

2011-07-29 12:18:04

謝謝我正要發佈子視圖解決方案，我發現了:) – Jan

self.imgView.layer.anchorPoint = CGPointMake(0.0,1.0); 
self.imgView.layer.position = CGPointMake(100,200.0); 
CGAffineTransform cgaRotateHr = CGAffineTransformMakeRotation(-(3.141/4)); 
[self.imgView setTransform:cgaRotateHr];

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2012-03-27 13:22:21 Babuli

這是一個老問題，但其他的解決方案並沒有爲我工作得很好，所以我想出了另一種解決方案：

旋轉圖像本質上是應用只是一個翻譯正常旋轉，確保你想旋轉的點在旋轉後仍然在同一個點上。爲此，請在旋轉前計算圖像中位置的CGPoint，在旋轉後獲取位置，並將差異作爲圖像上的平移，將其「捕捉」到正確的位置。下面是我一直在使用的代碼：

請記住，翻譯應通過CGAffineTransform應用，不要移動.center，因爲翻譯需要相對於旋轉，而CGAffineTransformTranslate（）需要關心這一點。

// Note: self is the superview of _imageView 

// Get the rotation point 
CGPoint rotationPointInSelf = self.center; // or whatever point you want to rotate around 
CGPoint rotationPointInImage = [_imageView convertPoint:rotationPointInSelf fromView:self]; 

// Rotate the image 
_imageView.transform = CGAffineTransformRotate(_imageView.transform, angle); 

// Get the new location of the rotation point 
CGPoint newRotationPointInImage = [_imageView convertPoint:rotationPointInSelf fromView:self]; 

// Calculate the difference between the point's old position and its new one 
CGPoint translation = CGPointMake(rotationPointInImage.x - newRotationPointInImage.x, rotationPointInImage.y - newRotationPointInImage.y); 

// Move the image so the point is back in it's old location 
_imageView.transform = CGAffineTransformTranslate(_imageView.transform, -translation.x, -translation.y);

來源

2013-06-05 17:45:47 Siegfoult

很好的答案！謝謝！ –

我正在使用此代碼繞點（0,0）旋轉。也許它可以幫助你弄清楚如何激活你想要的。

float width = self.view.frame.size.width; 
    float height = self.view.frame.size.height; 

    CGRect frame_smallView = CGRectMake(-width, -height, width, height); 
    UIView *smallView = [[UIView alloc] initWithFrame:frame_smallView]; 
    smallView.backgroundColor = darkGrayColor; 

    // Select x and y between 0.0-1.0. 
    // The default is (0.5f,0.5f) that is the center of the layer 
    // (1.0f,1.0f) is the right bottom corner 
    smallView.layer.anchorPoint = CGPointMake(1.0f, 1.0f); 

    // Rotate around this point 
    smallView.layer.position = CGPointMake(0, 0); 

    [self.view insertSubview:smallView belowSubview:self.navBar]; 

    [UIView animateWithDuration:1 
        animations:^{ 
         smallView.transform = CGAffineTransformMakeRotation(M_PI); 
        } 
        completion:^(BOOL finished){ 
         [self.navigationController popViewControllerAnimated:NO]; 
        }];

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2014-05-28 19:59:43 rcmcastro

旋轉的UIImageView周圍任意點

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