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我正在使用第三方颜色选取器轮（ISColorWheel- https://github.com/justinmeiners/ios-color-wheel）选取颜色并将其显示在屏幕上。如果启用特定按钮，我需要限制选择蓝色。在ColorPicker UIView上限制触摸 - iOS
当我看到拾色器库类，他们已经实施了下面的代码来限制旋钮以围绕拾色器移动。
- (void)setTouchPoint:(CGPoint)point
{
CGFloat width = self.bounds.size.width;
CGFloat height = self.bounds.size.height;
CGPoint center = CGPointMake(width/2.0, height/2.0);
// Check if the touch is outside the wheel
if (ISColorWheel_PointDistance(center, point) < _radius)
{
//NSLog(@"Distance is %f and Radius is %f",ISColorWheel_PointDistance(center, point),_radius);
_touchPoint = point;
}
else
{
// If so we need to create a drection vector and calculate the constrained point
CGPoint vec = CGPointMake(point.x - center.x, point.y - center.y);
float extents = sqrtf((vec.x * vec.x) + (vec.y * vec.y));
vec.x /= extents;
vec.y /= extents;
_touchPoint = CGPointMake(center.x + vec.x * _radius, center.y + vec.y * _radius);
NSLog(@"Touch Point is %f %f",_touchPoint.x,_touchPoint.y);
}
[self updateKnob];
}
上述代码限制用户将knobView从圆中移开。在我的情况下，我需要限制用户不要选择ColorPicker的蓝色。我如何实现它。如何找到蓝色的运动轨迹。