ios- zoom and rotate a masked UIImageView [closed]

问题

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

Have an image(source) masked by another image (frame)
User can drag,zoom, rotate the source image. The frame image keeps still.

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.

回答1:

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];

    }

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

回答2:

These both links will help you 100%.

http://code4app.net/ios/scale-an-image-by-pinch/507e21c36803fa4667000000

http://code4app.net/ios/Image-Cropper/4f8cc87f06f6e7d86c000000

回答3:

You could also put the frame image onto the scrollView that does the zooming, as a subview. That way, both images should zoom together.

来源：https://stackoverflow.com/questions/21586331/ios-zoom-and-rotate-a-masked-uiimageview

标签

ios

objective-c

uiimageview

uigesturerecognizer

mask