拖动，缩放和旋转多个UIImageviews [英] Drag, scale and rotate multiple UIImageviews

问题描述

到目前为止，我可以移动，缩放和旋转所有对象，但是多个对象可以一起移动。我要他们分开走。我想我必须将objectatIndex更改为1，但是它只会崩溃。

I've got it so far that I can move, scale and rotate all the objects, but the multiple objects all move together. I want them to move seperate. I guess I have to change the objectatIndex to 1, but it just crashes.

我使用了以下代码：

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

    NSArray *allTouches = [touches allObjects];

    UITouch* t;
    if([[event allTouches] count]==1){
        if (CGRectContainsPoint([Birdie frame], [[allTouches objectAtIndex:0] locationInView:theimageView]) && CGRectContainsPoint([imageViewauto frame], [[allTouches objectAtIndex:0] locationInView:theimageView])) {
            t=[[[event allTouches] allObjects] objectAtIndex:0];
            touch1=[t locationInView:nil];
        }
    }else{
        t=[[[event allTouches] allObjects] objectAtIndex:0];
        touch1=[t locationInView:nil];
        t=[[[event allTouches] allObjects] objectAtIndex:1];
        touch2=[t locationInView:nil];
    }
}

-(double)distance:(CGPoint)point1 toPoint:(CGPoint)point2
{
    double deltaX, deltaY;
    deltaX = point1.x - point2.x;
    deltaY = point1.y - point2.y;
    return sqrt(deltaX * deltaX + deltaY * deltaY);
}

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

    CGPoint currentTouch1;
    CGPoint currentTouch2;
    NSArray *allTouches = [touches allObjects];
    UITouch* t;
    float scale,rotation;

    if([[event allTouches] count]==1){
        t=[[[event allTouches] allObjects] objectAtIndex:0];
        if (CGRectContainsPoint([Birdie frame], [[allTouches objectAtIndex:0] locationInView:theimageView]) && CGRectContainsPoint([imageViewauto frame], [[allTouches objectAtIndex:0] locationInView:theimageView]))
        { 
            touch2=[t locationInView:nil];
            Birdie.center=CGPointMake(Birdie.center.x+touch2.x-touch1.x,Birdie.center.y+touch2.y-touch1.y);
            imageViewauto.center=CGPointMake(imageViewauto.center.x+touch2.x-touch1.x,imageViewauto.center.y+touch2.y-touch1.y);
            touch1=touch2;
        }
    }
    else if([[event allTouches] count]==2)
    {
        t=[[[event allTouches] allObjects] objectAtIndex:0];
        currentTouch1=[t locationInView:nil];

        t=[[[event allTouches] allObjects] objectAtIndex:1];
        currentTouch2=[t locationInView:nil];

        double distance1 =  [self distance:currentTouch1 toPoint:currentTouch2];
        double distance2 = [self distance:touch1 toPoint:touch2];

        if (distance2 == 0)
        {
            //handle the case where distance is zero
        }
        else {
            scale =distance1 / distance2;}

        rotation=atan2(currentTouch2.y-currentTouch1.y, currentTouch2.x-currentTouch1.x)-atan2(touch2.y-touch1.y,touch2.x-touch1.x);
        if(isnan(scale)){
            scale=1.0f;
        }
        NSLog(@"rotation %f",rotation);

        NSLog(@"scale %f",scale);

        if (CGRectContainsPoint([Birdie frame], [[allTouches objectAtIndex:0] locationInView:theimageView]) && CGRectContainsPoint([imageViewauto frame], [[allTouches objectAtIndex:0] locationInView:theimageView]))
        {

            Birdie.transform=CGAffineTransformScale(Birdie.transform, scale,scale);
            Birdie.transform=CGAffineTransformRotate(Birdie.transform, rotation);

            imageViewauto.transform=CGAffineTransformScale(imageViewauto.transform, scale,scale);
            imageViewauto.transform=CGAffineTransformRotate(imageViewauto.transform, rotation);
        }
        else // In case of scaling or rotating the background imageView
        {
            imageView.transform=CGAffineTransformScale(imageView.transform, scale,scale);
            imageView.transform=CGAffineTransformRotate(imageView.transform, rotation);
        }

        touch1=currentTouch1;
        touch2=currentTouch2;
    }
}

推荐答案

第一个总之，处理拖动，缩放和旋转的一种简单方法是像下面这样使用GestureRecognizer：

First of all, an easy way to handle drag, scale and rotate is to use GestureRecognizers like the bellow one:

    UIPinchGestureRecognizer *pinchRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(scale:)];
[pinchRecognizer setDelegate:self];
[self.view addGestureRecognizer:pinchRecognizer];

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

UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(move:)];
[panRecognizer setMinimumNumberOfTouches:1];
[panRecognizer setMaximumNumberOfTouches:1];
[panRecognizer setDelegate:self];
[self.view addGestureRecognizer:panRecognizer];

UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapped:)];
[tapRecognizer setNumberOfTapsRequired:1];
[tapRecognizer setDelegate:self];
[self.view addGestureRecognizer:tapRecognizer];

要处理多个UIImageView，可以使用接触点的位置，可以使用波纹管功能所以：

To handle multiple UIImageViews you may use the position of touched points, you can use the bellow functions to do so:

- (CGPoint)locationInView:(UIView*)view;   
- (CGPoint)locationOfTouch:(NSUInteger)touchIndex inView:(UIView*)view;

根据触摸的次数，您可以使用第一个或第二个功能，然后查看是否接触点位于考虑的UIImageView框架内，例如，可以按以下所示进行缩放：

According to the number of touched you can use either the first or second function, and then see if the touched point is inside the frame of considered UIImageView, for example for scaling you can do as what is show in bellow:

-(void)scale:(id)sender {

UIView * pinchView = [(UIPinchGestureRecognizer*)sender view];

CGPoint first_point = [sender locationOfTouch:0 inView:pinchView];
CGPoint second_point = [sender locationOfTouch:1 inView:pinchView];


if (CGRectContainsPoint(my_image_view.frame, first_point) && CGRectContainsPoint(my_image_view.frame, second_point)) {
    [self.view bringSubviewToFront:pinchView];

    if([(UIPinchGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) {

        lastScale = 1.0;
        return;
    }

    CGFloat scale = 1.0 - (lastScale - [(UIPinchGestureRecognizer*)sender scale]);

    CGAffineTransform currentTransform = my_image_view.transform;
    CGAffineTransform newTransform = CGAffineTransformScale(currentTransform, scale, scale);
    [my_image_view setTransform:newTransform];

    lastScale = [(UIPinchGestureRecognizer*)sender scale];}}

这篇关于拖动，缩放和旋转多个UIImageviews的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！