检测iOS中PAN姿势的方向 [英] Detecting the direction of PAN gesture in iOS

问题描述

在我的应用程序中有一个图像view.Im添加PAN姿势到该图像视图。

In my app there is a image view.Im adding PAN gesture to that image view.

这很好。

图片视图处于横向模式。

The image view is in landscape mode.

我想在用户平移到正确方向时增加标签的计数，向左方向。

I want to increase a count in label while user pan to right direction and decrease that count while user pan to left direction.

我搜索了很多，但没有找到解决方案。

I googled a lot but didn't find a solution for this.

请帮助我如何检测用户正在平移的方向（左/右）？

Can anyone please help me how to detect the direction in which the user is panning(left/right)?

推荐答案

您的手势识别器，使用 - （CGPoint）velocityInView：（UIView *）view; ：

In the target selector of your gesture recognizer, use - (CGPoint)velocityInView:(UIView *)view;:

- (void)panRecognized:(UIPanGestureRecognizer *)rec
{
    CGPoint vel = [rec velocityInView:self.view];
    if (vel.x > 0)
    {
        // user dragged towards the right
        counter++;
    }
    else
    {
        // user dragged towards the left
        counter--;
    }
}

Ps：我不知道这个方法，直到约。 3分钟前。谷歌的第一个点击是苹果的官方文档。

P.s.: I didn't know about this method until approx. 3 minutes before. One of Google's first hits was the official Apple documentation.

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