自定义实现moveable button

实现的效果图：

 

自定义MVButton，继承自UIButton.

属性声明如下：

@property (nonatomic) CGPoint beginPoint;
@property (nonatomic) BOOL    dragEnable;

 

//自定义button对触摸事件进行响应
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    //dragEnable = NO 则不响应动作
    if (!_dragEnable) {
        return;
    }
    UITouch *touch = [touches anyObject];
    
    //获取button的当前位置
    _beginPoint = [touch locationInView:self];
}

　

//拖动自定义button时响应
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    if (!_dragEnable) {
        return;
    }
    UITouch *touch = [touches anyObject];
    
    //获取要移动到的目标位置
    CGPoint nowPoint = [touch locationInView:self];
    
    //确定目标位置与开始位置的偏移量
    float offsetX = nowPoint.x - _beginPoint.x;
    float offsetY = nowPoint.y - _beginPoint.x;
    
    //按照button的center属性移动button
    self.center = CGPointMake(self.center.x + offsetX, self.center.y + offsetY);
}

　

在ViewController.m中实现的代码如下：

首先导入自定义的button：

#import "MVButton.h"

具体实现：

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    MVButton *mvButton = [[MVButton alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
    mvButton.backgroundColor = [UIColor yellowColor];
    mvButton.dragEnable = YES;
    
    [self.view addSubview:mvButton];
}