自定义控件拖拽效果
ios:
1.自定义view继承自UIView
2.覆盖touchesMoved实现具体逻辑
- (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
//取得UITouch对象
UITouch *touch = [touches anyObject];
//获取上一个点
CGPoint p = [touch previousLocationInView:self];
//获取当前点
CGPoint currp = [touch locationInView:self];
//产生平移拖拽效果
self.transform = CGAffineTransformTranslate(self.transform, currp.x - p.x, currp.y - p.y);
}
android：
1.自定义view继承自View
2.覆盖onTouchEvent实现具体逻辑
private int x, y;
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()){
case MotionEvent.ACTION_DOWN:
x = (int) event.getRawX();
y = (int) event.getRawY();
break;
case MotionEvent.ACTION_MOVE:
int mx = (int)event.getRawX();
int my = (int)event.getRawY();
// setTranslationX(getTranslationX()+mx-x);
// setTranslationY(getTranslationY()+my-y);
layout(getLeft()+mx-x,getTop()+my-y,getLeft()+getMeasuredWidth()+mx-x,getTop()+getMeasuredHeight()+my-y);
x = mx;
y = my;
break;
}
return true;
}
UIGestureRecognizer
iOS 3.2之后，苹果推出了手势识别功能（Gesture Recognizer），在触摸事件处理方面，利用UIGestureRecognizer，能轻松识别用户在某个view上面做的一些常见手势。
UIGestureRecognizer
UIGestureRecognizer是一个抽象类，定义了所有手势的基本行为，使用它的子类才能处理具体的手势
UITapGestureRecognizer(敲击)
UIPinchGestureRecognizer(捏合，用于缩放)
UIPanGestureRecognizer(拖拽)
UISwipeGestureRecognizer(轻扫)
UIRotationGestureRecognizer(旋转)
UILongPressGestureRecognizer(长按)
手势识别器的用法相似，比如UITapGestureRecognizer的使用步骤如下：
//创建手势识别器对象
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] init];
//设置手势识别器对象的具体属性
// 连续敲击2次
tap.numberOfTapsRequired = 2;
// 需要2根手指一起敲击
tap.numberOfTouchesRequired = 2;
//添加手势识别器到对应的view上
[self.iconView addGestureRecognizer:tap];
监听手势的触发
[tap addTarget:self action:@selector(tapIconView:)];
上面的拖拽效果也可以用这种方式实现：
//页面加载完成时调用
- (void)viewDidLoad {
[super viewDidLoad];
//创建手势识别器对象
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];
//添加手势识别器到对应的view上
[self.imageView addGestureRecognizer:pan];
}
- (void)pan:(UIPanGestureRecognizer *)pan
{
// 获取手势的触摸点
// CGPoint curP = [pan locationInView:self.imageView];
// 获取手势的移动，也是相对于最开始的位置
CGPoint transP = [pan translationInView:self.imageView];
self.imageView.transform = CGAffineTransformTranslate(self.imageView.transform, transP.x, transP.y);
// 复位
[pan setTranslation:CGPointZero inView:self.imageView];
//判断当前手指状态
//if (pan.state == UIGestureRecognizerStateBegan) {//手指按下时类似于Android中的ACTION_DOWN
//}
}
