监听手指长按在view的路径，具体一连串坐标
UITouch只提供了点击屏幕的具体坐标。没有提供，手指的屏幕滑动，具体一连串坐标。
只好通过以下方法来，监听长按的路径。
直接上代码：
#import "ViewController.h"
@interface ViewController ()
{
UIView *touchView;
}
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self longPressedOnView];
}
-(void)longPressedOnView{
touchView = [[UIView alloc] init];
touchView.backgroundColor = [UIColor brownColor];
touchView.frame = CGRectMake(0, [UIScreen mainScreen].bounds.size.height / 2 - [UIScreen mainScreen].bounds.size.height / 4, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height / 2);
[self.view addSubview:touchView];
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressedOncell:)];
[touchView addGestureRecognizer:longPress];
longPress.allowableMovement = NO;
//长按时间，多久后开始触发
longPress.minimumPressDuration = 1;
}
-(void)longPressedOncell:(UILongPressGestureRecognizer *)longPress{
CGPoint p = [(UILongPressGestureRecognizer *)longPress locationInView: touchView];
/*
UIGestureRecognizerStateBegan 可以理解为长按手势开始时触发
UIGestureRecognizerStateChanged 可以理解为长按手势开始改变时触发
UIGestureRecognizerStateEnded 可以理解为长按手势结束时触发
还有其他的一些longPress.state不一一列出来了，感兴趣的可以自行了解
*/
if (longPress.state == UIGestureRecognizerStateChanged) {
NSLog(@"长按手势开始改变p=%@",NSStringFromCGPoint(p));
}
if (longPress.state == UIGestureRecognizerStateBegan) {
NSLog(@"长按手势开始触发p=%@",NSStringFromCGPoint(p));
}
else {
NSLog(@"结束结束");
}
}
