用手指使 UIView 可拖动

Posted 2023-05-08

【中文标题】用手指使 UIView 可拖动

【英文标题】：Make a UIView draggable with the finger

【发布时间】：2013-01-18 23:46:02

【问题描述】：

我有mainViewController，但我有一个小的UIView，当您在MKMapKit 中点击MKAnnotationView 时会激活它，所以我需要UIView 可以在屏幕的任何部分拖动.

我的应用的示例截图：

圆圈是点的一个例子，我想我可以拖动“小”UIView的任何点。

我尝试使用UITapGestureRecognizer，但它不起作用，因为我的代码不够好，而且我无法使其可拖动，因为它只是点击，而不是点击和移动。

我希望你能帮助我。

【参考方案1】：

使用UIPanGestureRecognizer 而不是UITapGestureRecognizer 设置userInteractionEnabled = YES 供您查看 查看这个关于手势识别器的精彩教程：Touches。有一个很好的拖动视图的例子。

【讨论】：

感谢您的回答，我会研究我测试结果的那个项目，我认为它可以帮助我很多，谢谢。

【参考方案2】：

For create draggable and resizable UIView This example (with source code) really useful for you.

同时阅读This Document和This Document这个文档与UIPanGestureRecognizer相关

【参考方案3】：

在@borrrden 推荐后编辑

UIPanGestureRecognizer 适合。在你的处理函数中检查它是state 变量。

typedef enum 
   UIGestureRecognizerStatePossible,

   UIGestureRecognizerStateBegan,     // this will be the value on touch
   UIGestureRecognizerStateChanged,   // ~ on drag
   UIGestureRecognizerStateEnded,     // ~ on end of touch event
   UIGestureRecognizerStateCancelled,

   UIGestureRecognizerStateFailed,

   UIGestureRecognizerStateRecognized = UIGestureRecognizerStateEnded
 UIGestureRecognizerState;

【讨论】：

"Changed" 不会被点击手势调用，因为它没有意义。

没错，我会编辑帖子指向UIPanGestureRecognizer

【参考方案4】：

我用它在我的应用中缩放和拖动 UIView。

1) 首先确保将以下内容添加到您的实现中，并将出口连接到您故事板中的视图

#import <QuartzCore/QuartzCore.h>

@interface yourclass () 
    BOOL isDragging;

@property (weak, nonatomic) IBOutlet UIImageView *outletMainView; // View that contains the view we want to drag
@property (weak, nonatomic) IBOutlet UIImageView *outletRedDot; // The view we want to drag in the main view

当触摸开始时，当用户触摸特定视图时，我会稍微缩放视图，这里是红点

// ANIMATE RED DOT WHEN START DRAGING IT
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
    UITouch *touch = [touches anyObject];
    CGPoint touchLocation = [touch locationInView:self.outletMainView];

    CGRect redDotRect = [self.outletRedDot frame];
    if (CGRectContainsPoint(redDotRect, touchLocation)) 
        isDragging = YES;
        NSLog(@"Red Dot tapped!");
        [UIView animateWithDuration:0.2
                              delay:0.0
                            options:UIViewAnimationOptionCurveEaseOut
                         animations:^
                             self.outletRedDot.transform = CGAffineTransformMakeScale(1.75, 1.75);
                         
                         completion:^(BOOL finished) 
                         ];
     else 
        return;
    

2）然后我将视图设置为跟随手指点的点

// ANIMATE AND MOVE RED DOT WHEN WE DRAG IT
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event 
    UITouch *touch = [touches anyObject];
    CGPoint touchLocation = [touch locationInView:self.outletMainView];

    if (isDragging) 
        [UIView animateWithDuration:0.0f
                              delay:0.0f
                            options:(UIViewAnimationOptionBeginFromCurrentState|UIViewAnimationOptionCurveEaseInOut)
                         animations:^
                             self.outletRedDot.center = touchLocation;
                             NSLog(@"X: %0.2f Y: %0.2f",touchLocation.x-redDotStartCenter.x, redDotStartCenter.y-touchLocation.y);
                         
                         completion:NULL];
    

3) 最后，当拖动结束时，视图会重置为原始比例

// RESET RED DOT WHEN WE STOP DRAGGING
- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event 
    UITouch *touch = [touches anyObject];
    CGPoint touchLocation = [touch locationInView:self.outletMainView];

    CGRect redDotRect = [self.outletRedDot frame];
    if (CGRectContainsPoint(redDotRect, touchLocation)) 
        [UIView animateWithDuration:0.1
                              delay:0.0
                            options:0
                         animations:^
                             self.outletRedDot.transform = CGAffineTransformMakeScale(1.0, 1.0);
                         
                         completion:^(BOOL finished) 
                         ];
    
    isDragging = NO;