ios-缩放并旋转蒙版的UIImageView [英] ios- zoom and rotate a masked UIImageView

问题描述

我是iOS的新手，需要满足以下需求.请给我一些有关如何执行此操作的指示.谢谢！

I'm new to iOS and need to have the needs below. Please give me some directions on how to do this. Thanks!

• 具有被另一个图像(框架)遮盖的图像(源)
• 用户可以拖动，缩放，旋转源图像.框架图像保持静止.

我知道如何使用CGImageCreateWithMask以及如何将uiimageview放在scrollview中以进行缩放.但是我不知道如何将它们组合在一起并创建自定义控件.

I know how to use CGImageCreateWithMask and how to put uiimageview inside a scrollview for pinch to zoom. But I don't know how to combine these together and make a custom control.

推荐答案

要旋转图像，可以使用UIPanGestureRecognizer，要放大/缩小，可以使用UIPinchGestureRecognizer.可能是下面的代码可以帮助您.

To rotate an image you can use UIPanGestureRecognizer and to zoom in/out you can use UIPinchGestureRecognizer. May be the code below could help you.

// In your vieDidLoad use:

    UIPanGestureRecognizer *pan=[[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(panned:)];

    UIPinchGestureRecognizer *pinch=[[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinched:)];
    [self.imageview addGestureRecognizer:pinch];
    [self.imageview addGestureRecognizer:pan];

    and add the selector methods:

    // To zoom in/out
    - (void)pinched:(UIPinchGestureRecognizer *)sender {

    if (sender.scale >1.0f && sender.scale < 2.5f) {
    CGAffineTransform transform = CGAffineTransformMakeScale(sender.scale, sender.scale);
    imageview.transform = transform;
    }
    }

    //To rotate
    -(void) panned:(UIGestureRecognizer *)gesture
    {
    CGPoint translatedPoint = [(UIPanGestureRecognizer*)gesture translationInView:imageview];

    if([(UIPanGestureRecognizer*)gesture state] == UIGestureRecognizerStateBegan) {
        _firstX = [imageview center].x;
        _firstY = [imageview center].y;
    }   
    translatedPoint = CGPointMake(_firstX+translatedPoint.x, _firstY+translatedPoint.y);  
    [imageview setCenter:translatedPoint];

    }

在viewDidLoad中，还应将框架作为子视图添加到imageview.

in your viewDidLoad your should also add your frame as as subview to the imageview.

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