Question

ios 怎么拖拽自定义view

Answer 1

这个版本是基于viewcontroller的实现，并未子类化view;self.localview是你持有的小窗口,beginpoint需要你在viewcontroller中自己定义

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
if (!self.isInView) // 仅当取到touch的view是小窗口时，我们才响应触控，否则直接return
{
return;
}

UITouch *touch = [touches anyObject];
CGPoint currentPosition = [touch locationInView:self.localView];
//偏移量
float offsetX = currentPosition.x - beginpoint.x;
float offsetY = currentPosition.y - beginpoint.y;
//移动后的中心坐标
self.localView.center = CGPointMake(self.localView.center.x + offsetX, self.localView.center.y + offsetY);

//x轴左右极限坐标
if (self.localView.center.x > (self.localView.superview.frame.size.width-self.localView.frame.size.width/2))
{
CGFloat x = self.localView.superview.frame.size.width-self.localView.frame.size.width/2;
self.localView.center = CGPointMake(x, self.localView.center.y + offsetY);
}
else if (self.localView.center.x < self.localView.frame.size.width/2)
{
CGFloat x = self.localView.frame.size.width/2;
self.localView.center = CGPointMake(x, self.localView.center.y + offsetY);
}

//y轴上下极限坐标
if (self.localView.center.y > (self.localView.superview.frame.size.height-self.localView.frame.size.height/2))
{
CGFloat x = self.localView.center.x;
CGFloat y = self.localView.superview.frame.size.height-self.localView.frame.size.height/2;
self.localView.center = CGPointMake(x, y);
}
else if (self.localView.center.y <= self.localView.frame.size.height/2)
{
CGFloat x = self.localView.center.x;
CGFloat y = self.localView.frame.size.height/2;
self.localView.center = CGPointMake(x, y);
}
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
if (touch.view.frame.size.width == 120) // 120为小窗口的宽度（简单起见这里使用硬编码示例），用来判断触控范围;仅当取到touch的view是小窗口时，我们才响应触控
{
self.isInView = YES;
}
else
{
self.isInView = NO;
}
beginpoint = [touch locationInView:self.localView];

[super touchesBegan:touches withEvent:event];
}