Question

有没有办法检测用户完成的旋转是顺时针还是逆时针直接???

我搜索了但却找不到答案！

我的代码如下所示：

 UIGestureRecognizer *recognizer;
 recognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(spin)];
 [self.rotating addGestureRecognizer:recognizer];
 [recognizer release];

Answer 1

rotation属性会以弧度告诉您rotation。负值表示旋转是顺时针方向，正值表示逆时针方向。

示例：

UIGestureRecognizer *recognizer;
recognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(spin:)];  // <-- Note the colon after the method name
[self.rotating addGestureRecognizer:recognizer];
[recognizer release];

- (void)spin:(UIGestureRecognizer *)gestureRecognizer {
    CGFloat rotation = gestureRecognizer.rotation;
    if (rotation < 0) {
        // clockwise
    } else {
        // counter-clockwise
    }
}

Answer 2

快速版本-假设您已将UIRotationGestureRecognizer连接到IBAction，并将UIRotationGestureRecognizer作为参数recognizer传入。您可以使用以下命令轻松测试方向：

if recognizer.rotation < 0 {
    print("Negative rotation value means anticlockwise rotation detected")
} else if recognizer.rotation > 0 {
    print("Positive rotation value means clockwise rotation detected")
}

iphone开发 - UIRotationGestureRecognizer（顺时针和逆时针检测）？

2 个答案: