如何判断touch到子视图或离开视图

 

这是在ios开发中常见的功能。即，touch移动事件，是移动到当前视图的子视图中，还是移动到当前视图以外了。

办法是，继承UIView，覆盖touchesMoved方法：

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{ 
    UITouch *touch=[touches anyObject]; 
    if (![self pointInside:[touch locationInView:self] withEvent:nil]) {
        NSLog(@"touches moved outside the view"); 
    }else { 
        UIView *hitView=[self hitTest:[[touches anyObject] locationInView:self] withEvent:nil]; 
        if (hitView==self) { 
            NSLog(@"touches moved in the view"); 
        }else{ 
            NSLog(@"touches moved in the subview"); 
        } 
    } 
}