iOS Objective-C记录滑动时起始和终点坐标值

最近接到一个需求，是要记录一个TextView中手指滑动时候的接触屏幕的起始和终点坐标(相对于屏幕的)，同时记录滑动时间。

查了挺多资料，好像都不能完美达到需求的目标，最后用以下代码完美解决：

首先我们知道TextView是ScrollView的子类，那么我们遵循了UITextViewDelegate后，会有以下方法：

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView; //滑动即将开始时触发
- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset; //手指滑动离开时触发

有了以上两个方法，那接下来我们就需要在这两个方法里面获取到Touch的坐标：

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{
    //获取滑动手势
    switch (scrollView.panGestureRecognizer.state) {
        //当手势识别为开始滑动时
        case UIGestureRecognizerStateBegan:
        {
            //locationInView这个方法很重要，它是UIGestureRecognizer的实例方法，这里UIPanGestureRecognizer是它的子类
            CGPoint point = [scrollView.panGestureRecognizer locationInView:self.view]; 
            self.startX = [NSString stringWithFormat:@"%0.f",point.x]; //我这里取整数
            self.startY = [NSString stringWithFormat:@"%0.f",point.y];
            NSLog(@"startX:%@, startY:%@", _startX, _startY);
            self.startTime = [NSDate date];
            break;
        }
        default:
            break;
    }
}

- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset{
    switch (scrollView.panGestureRecognizer.state) {
        case UIGestureRecognizerStateEnded:
        {
            CGPoint point = [scrollView.panGestureRecognizer locationInView:self.view];
            NSString *endX = [NSString stringWithFormat:@"%0.f",point.x];
            NSString *endY = [NSString stringWithFormat:@"%0.f",point.y];
            NSLog(@"endX:%@, endY:%@", endX, endY);
            NSString *duration = [NSString stringWithFormat:@"%0.lf",[[NSDate date] timeIntervalSinceDate:self.startTime] * 1000];
            NSLog(@"duration: %@",duration);
        }
            break;
            
        default:
            break;
    }
}

以上就是完美的解决方法了，代码不难，就只是要熟悉scrollView的代理方法和手势，希望能帮助到你们，求点赞投币哈哈哈