Question

我对这个库有点困惑

https://github.com/Zedenem/UICircularSlider

我想绘制最小圆形颜色作为渐变颜色。我已将此集成到我的项目中，并且我看到TBCircular滑块带有渐变，但我需要对该比较进行比UICircularSlider更多的自定义。

到目前为止，我已尝试使用`UICircularSlider＆＃39;

    - (CGPoint)drawCircularTrack:(float)track atPoint:(CGPoint)center withRadius:(CGFloat)radius inContext:(CGContextRef)context {

    UIGraphicsPushContext(context);
    CGContextBeginPath(context);
    float angleFromTrack = translateValueFromSourceIntervalToDestinationInterval(track, self.minimumValue, self.maximumValue, 0, 2*M_PI);
    CGColorSpaceRef space = CGColorSpaceCreateDeviceRGB();

    CGGradientRef g[4];

    CGFloat comps0[] = {1.0,1.0,1.0,1.0,0.0,1.0,1.0,1.0};
    CGFloat locs[] = {0,1};
    g[0] = CGGradientCreateWithColorComponents(space, comps0, locs, 2);

    CGFloat comps1[] = {1.0,1.0,1.0,1.0,1.0,0.0,1.0,1.0};
    g[1] = CGGradientCreateWithColorComponents(space, comps1, locs, 2);

    CGFloat comps2[] = {1.0,1.0,1.0,1.0,1.0,1.0,0.0,1.0};
    g[2] = CGGradientCreateWithColorComponents(space, comps2, locs, 2);

    CGFloat comps3[] = {1.0,1.0,1.0,1.0,0.5,0.0,0.5,1.0};
    g[3] = CGGradientCreateWithColorComponents(space, comps3, locs, 2);
    CGFloat startAngle = -M_PI_2;
    CGFloat endAngle = startAngle + angleFromTrack;
        //CGContextMoveToPoint(context, startAngle,endAngle);
    CGContextAddArc(context, center.x, center.y, radius, startAngle, endAngle, NO);
    CGPoint arcEndPoint = CGContextGetPathCurrentPoint(context);
    CGContextStrokePath(context);
    UIGraphicsPopContext();
//      CGContextDrawRadialGradient(context, g[0], CGPointMake(radius, radius), startAngle, CGPointMake(radius,radius), endAngle, 0);
    CGContextClip(context);
    CGContextDrawRadialGradient(context, g[0], CGPointMake(arcEndPoint.x, arcEndPoint.y),1, CGPointMake(arcEndPoint.x, arcEndPoint.y),kLineWidth, 0);
    return arcEndPoint;

}

使用

获取整个视图的渐变，而不是在绘制的圆圈中

CGContextAddArc(context, center.x, center.y, radius, startAngle, endAngle, NO);

我只想添加 AddArc 区域，而不是整个视图。

并在Gradient Color To CGContextRef

之后做了一些事情

渐变色的UICircular进展？

0 个答案: