iPhone：如何向左或向右旋转 UIImageview？

Posted 2023-02-27

【中文标题】iPhone：如何向左或向右旋转 UIImageview？

【英文标题】：iPhone: How to Rotate a UIImageview Left or Right?

【发布时间】：2010-02-04 11:01:29

【问题描述】：

我想以以下方式旋转 UIImageView：如果我按住 imageview 并将手指向左移动，那么 imageview 应该向右旋转（反之亦然）。

这里是链接Balance

【参考方案1】：

我去年摆弄过这个。事实证明它比我想象的要复杂。 IIRC，这个小班做到了你想要的。它是一个 UIButtonSubclass，它显示图像并响应点击和拖动。请注意，这只是临时代码。它不做任何内存管理、清理等。

#import <UIKit/UIKit.h>
#import "BackgroundImageButton.h"
#import "WiggleImageView.h"

@interface StickerButton : UIButton 
    //ivars used to control selection animaiton
    CGAffineTransform startTransform;
    BOOL currentlyAnimating;
    BOOL shouldAnimate; 
    //ivars to handle touches and control events
    BOOL wasDrag;
    BOOL wasTouchDown;
  WiggleImageView * imgView;

//ivars used to control selection animaiton
@property CGAffineTransform startTransform;
@property(nonatomic, retain)  WiggleImageView *imgView;
@property BOOL currentlyAnimating;
@property BOOL shouldAnimate;
//ivars to handle touches and control events
@property BOOL wasDrag;
@property BOOL wasTouchDown;


#pragma mark Initialization
-(id) initWithImage:(UIImage *)anImage atCenterPoint:(CGPoint) centerPoint;

#pragma mark Selection Animation Methods
-(void) animateSelection;
-(void) animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context;

#pragma mark Self Touch Methods  //not as dirty as it sounds.
-(void) touchDragSelf:(id)sender withEvent:(UIEvent *) theEvent;
-(void) touchDownSelf:(id)sender withEvent:(UIEvent *) theEvent;
-(void) touchUpSelf:(id)sender withEvent:(UIEvent *) theEvent;

#pragma mark Graphic Edit Methods
-(void) rotateRight;
-(void) rotateLeft;
-(void) scaleUp;
-(void) scaleDown;
-(void) select;
-(void) deselect;
-(void) translateMoveByX:(CGFloat) dx andY:(CGFloat) dy; //used by self to account for translated coordinates
-(void) frameMoveByX:(CGFloat) dx andY:(CGFloat) dy; //used by external to move frame in superview    
@end

#import "StickerButton.h"

@implementation StickerButton
@synthesize startTransform;
@synthesize currentlyAnimating;
@synthesize shouldAnimate;
@synthesize wasDrag;
@synthesize wasTouchDown;
@synthesize imgView;


#pragma mark Initialization
- (id)initWithFrame:(CGRect)frame 
    if (self = [super initWithFrame:frame]) 
        startTransform=self.transform;
        currentlyAnimating=NO;
        shouldAnimate=NO;
        wasDrag=NO;
        wasTouchDown=NO;
        self.adjustsImageWhenDisabled=NO;
        self.adjustsImageWhenHighlighted=NO;
        self.showsTouchWhenHighlighted=NO;
        [self addTarget:self action:@selector(touchDownSelf:withEvent:) forControlEvents:UIControlEventTouchDown];
        [self addTarget:self action:@selector(touchDragSelf:withEvent:) forControlEvents:UIControlEventTouchDragInside];
        [self addTarget:self action:@selector(touchUpSelf:withEvent:) forControlEvents:UIControlEventTouchUpInside];
    
    return self;


-(id) initWithImage:(UIImage *)anImage atCenterPoint:(CGPoint) centerPoint
    CGFloat xOrigin,yOrigin;
    xOrigin=centerPoint.x-(anImage.size.width/2);
    yOrigin=centerPoint.y-(anImage.size.height/2);
    [self initWithFrame:CGRectMake(xOrigin, yOrigin, anImage.size.width, anImage.size.height)];
    WiggleImageView *w=[[WiggleImageView alloc] initWithFrame:self.bounds];
    imgView=w;
    imgView.image=anImage;
    [self addSubview:imgView];
    return self;
//------------------------------------initWithImage:atCenterPoint:------------------------------------



#pragma mark Selection Animation Methods
-(void) animateSelectedThrob
    if (!currentlyAnimating) 
        NSLog(@"animating");
        currentlyAnimating=YES;
        //startTransform=self.transform; //this has to be saved to prevent some kind of rounding error from gradually rotating the view
        [UIView beginAnimations:@"selectionAnimation" context:nil];
        [UIView setAnimationDelegate:self];
        [UIView setAnimationDuration:0.1];
        [UIView setAnimationRepeatCount:1];
        [UIView setAnimationRepeatAutoreverses:YES];
        self.transform=CGAffineTransformScale(self.transform, 1.1, 1.1);
        [UIView commitAnimations];
     
//-------------------------------------(void) animateSelectedThrob------------------------------------


-(void) animateSelection
    if (!currentlyAnimating) 
        //NSLog(@"animating");
        currentlyAnimating=YES;
        startTransform=self.transform; //this has to be saved to prevent some kind of rounding error from gradually rotating the view
        [UIView beginAnimations:@"selectionAnimation" context:nil];
        [UIView setAnimationDelegate:self];
        [UIView setAnimationDuration:0.1];
        [UIView setAnimationRepeatCount:2];
        [UIView setAnimationRepeatAutoreverses:YES];
        self.transform=CGAffineTransformRotate(self.transform, (2 * M_PI / 180) );
        [UIView commitAnimations];
     

//-------------------------------------(void) animateSelection------------------------------------

-(void) animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context
    self.transform=startTransform;
    currentlyAnimating=NO;
    if (shouldAnimate) 

        [self animateSelection];
       
//------------------------------------animationDidStop:finished:context:------------------------------------

#pragma mark Self Touch Methods

-(void) touchDownSelf:(id)sender withEvent:(UIEvent *) theEvent
    NSLog(@"touchDownSelf");
    wasTouchDown=YES;
    shouldAnimate=NO;
//------------------------------------touchDownSelf:withEvent:------------------------------------

-(void) touchDragSelf:(id)sender withEvent:(UIEvent *) theEvent
    NSLog(@"touchDragSelf");
    if ([[theEvent touchesForView:self] count]==1) 
        UITouch *t=[[theEvent touchesForView:self] anyObject];
        CGPoint l,p;
        l=[t locationInView:self];
        p=[t previousLocationInView:self];
        [self translateMoveByX:(l.x-p.x) andY:(l.y-p.y)];
        wasDrag=YES;        
    

//------------------------------------touchDragSelf:withEvent:------------------------------------

-(void) touchUpSelf:(id)sender withEvent:(UIEvent *) theEvent
    NSLog(@"touchUpSelf");
//  if (!wasDrag && wasTouchDown) 
//      [self select];
//  
    if (wasTouchDown) 
        [self select];
    
    wasDrag=NO;
    wasTouchDown=NO;
//------------------------------------touchUpSelf:withEvent:------------------------------------

#pragma mark Graphic Edit Methods 
-(void) rotateRight
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.1];
    [UIView setAnimationBeginsFromCurrentState:YES];
    self.transform=CGAffineTransformRotate(self.transform, (M_PI / 180) );
    [UIView commitAnimations];  
//-------------------------------------(void) rotateRight------------------------------------

-(void) rotateLeft
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.1];
    [UIView setAnimationBeginsFromCurrentState:YES];
    self.transform=CGAffineTransformRotate(self.transform, (-1*M_PI / 180) );
    [UIView commitAnimations];
//-------------------------------------(void) rotateLeft------------------------------------

-(void) scaleUp
    //todo add variable to track total scale so it doesn't get to big and cause problems
    shouldAnimate=NO;
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.1];
    [UIView setAnimationBeginsFromCurrentState:YES];
    self.transform=CGAffineTransformScale(self.transform, 1.1, 1.1);
    [UIView commitAnimations];
    startTransform=self.transform;
//-------------------------------------(void) scaleUp------------------------------------

-(void) scaleDown
    //todo add variable to track total scale so it doesn't get to small and cause problems
    shouldAnimate=NO;
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.1];
    [UIView setAnimationBeginsFromCurrentState:YES];
    self.transform=CGAffineTransformScale(self.transform, 0.9, 0.9);
    [UIView commitAnimations];
    startTransform=self.transform;
//-------------------------------------(void) scaleDown------------------------------------

-(void) select 
    [self animateSelectedThrob];
    imgView.shouldWiggle=YES;

//-------------------------------------(void) select------------------------------------

-(void) deselect
    imgView.shouldWiggle=NO;


-(void) translateMoveByX:(CGFloat) dx andY:(CGFloat) dy //necessary for all points that orignate within the transformed view
    NSLog(@"dx=%f,dy=%f",dx,dy);
    shouldAnimate=NO;
    self.transform=CGAffineTransformTranslate(self.transform, dx,dy);
    startTransform=self.transform;
//------------------------------------translateMoveByX:andY:------------------------------------

-(void) frameMoveByX:(CGFloat) dx andY:(CGFloat) dy //necessary for all points that originate outside the transformed view

    self.frame=CGRectMake(self.frame.origin.x+dx, self.frame.origin.y+dy, self.frame.size.width, self.frame.size.height);
//------------------------------------frameMoveByX:andY:------------------------------------
- (void)drawRect:(CGRect)rect 
    // Drawing code


- (void)dealloc 
    [super dealloc];


@end

【讨论】：

另一个自定义类。当您删除应用程序时，它旨在创建类似于跳板上的摆动效果。这与您的问题无关。你想看看 rotateRight 和 rotateLeft 方法和 self touch 方法。请注意，这些方法只是旋转视图的视觉显示，不会影响视图显示的实际图像，即如果您保存视图或将其合成到另一个视图中，您将获得图像的原始方向。

好的，现在告诉我，我正在创建一个球并将其从屏幕顶部发送到底部。为此，我拍摄了 3 张图像（如 3 个球），现在我在创建时随机选择球那么我如何检测哪个球被相交？

【参考方案2】：

您可以在控制器中使用 ivar 来跟踪拖动的开始。当您收到“触地”事件时，请保存起点。当您收到“触摸移动”事件时，计算从当前点到保存点的距离。两者之间的欧几里得距离可以为您提供旋转（告诉您旋转方向的符号）。适当缩放旋转（即，可能一半的视图宽度相当于 180 度），并设置图像变换的旋转。

【讨论】：

我没有任何现有的代码。我只是解释了我将如何开始解决这个问题。您应该能够毫不费力地将上面的描述翻译成代码！玩得开心...

好的，我得到了一半，但问题是 ImageView 在旋转时得到 ZigZagged。如何解决这个问题？它也只在从起点向左或向右旋转时才向左或向右旋转。我的意思是我只希望它在我将 Imageview 向左或向右移动时始终旋转。还有一个问题，您是否看过上面的链接。我想要它完全一样，请看看并指导正确的方向

图像变得“锯齿形”是什么意思？如果你想有一个累积的旋转效果，你需要添加一个 ivar 来存储之前的旋转，并将其添加到当前的旋转中，因为用户从起点拖动。您指的是哪个链接？没看到？

我已经添加了链接，请看一下