拖动、缩放和旋转多个 UIImageview

Posted 2023-03-12

【中文标题】拖动、缩放和旋转多个 UIImageview

【英文标题】：Drag, scale and rotate multiple UIImageviews

【发布时间】：2011-04-28 16:53:35

【问题描述】：

到目前为止，我已经可以移动、缩放和旋转所有对象，但是多个对象都一起移动。我希望他们分开搬家。我想我必须将 objectatIndex 更改为 1，但它只是崩溃了。

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;
    

【参考方案1】：

首先，处理拖动、缩放和旋转的一种简单方法是使用 GestureRecognizers，如下所示：

    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 UIImageViews，您可以使用触摸点的位置，您可以使用以下函数：

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

根据触摸的次数，你可以使用第一个或第二个函数，然后查看触摸点是否在考虑的 UIImageView 的框架内，例如缩放你可以如下所示：

-(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];

【参考方案2】：

它的工作原理

-(void)scale:(id)sender 

    if([(UIPinchGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan) 
        _lastScale = 1.0;
    

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

    CGAffineTransform currentTransform = self.transform;
    CGAffineTransform newTransform = CGAffineTransformScale(currentTransform, scale, scale);

    [self setTransform:newTransform];


    _lastScale = [(UIPinchGestureRecognizer*)sender scale];
    [self showOverlayWithFrame:self.frame];



-(void)rotate:(id)sender 

    if([(UIRotationGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) 

        _lastRotation = 0.0;

        return;
    
    CGFloat rotation = 0.0 - (_lastRotation - [(UIRotationGestureRecognizer*)sender rotation]);

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

    [self setTransform:newTransform];
    _lastRotation = [(UIRotationGestureRecognizer*)sender rotation];

    [self showOverlayWithFrame:self.frame];



-(void)move:(id)sender 

    CGPoint translatedPoint = [(UIPanGestureRecognizer*)sender translationInView:self];

     if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan) 
         _firstX = [self center].x;
         _firstY = [self center].y;
    

    translatedPoint = CGPointMake(_firstX+translatedPoint.x, _firstY+translatedPoint.y);

    [self setCenter:translatedPoint];


    [self showOverlayWithFrame:self.frame];

    NSLog(@"after move x= %f     y=%f "  , _firstX,_firstY);