jbchartview中的渐变

时间:2015-12-25 06:20:59

标签: xcode swift jbchartview

尝试使条形为渐变颜色,但无法找到有关如何执行此操作的任何文档。看起来这是正确的功能。只需要在括号中键入内容需要帮助。不关心真正的颜色。

func barGradientForBarChartView(barChartView: JBBarChartView!) -> CAGradientLayer! {


}

感谢您的帮助!

2 个答案:

答案 0 :(得分:0)

管理好了解决这个问题。想我会发布任何其他人需要的代码。请记住,它涵盖了所有的酒吧。您无法通过索引将它们与实心条分开。

func barGradientForBarChartView(barChartView: JBBarChartView) -> CAGradientLayer {
    let topColor = UIColor.orangeColor()
    let bottomColor = UIColor.blueColor()

    let gradientColors: [CGColor] = [topColor.CGColor, bottomColor.CGColor]
    let gradientLocations: [Float] = [0.0, 1.0]

    let gradientLayer: CAGradientLayer = CAGradientLayer()
    gradientLayer.colors = gradientColors
    gradientLayer.locations = gradientLocations

    return gradientLayer
}

答案 1 :(得分:0)

标题包含必要文档的仅供参考。同样,README是一个很好的起点。

/**
 *  If you already implement barChartView:barViewAtIndex: delegate - this   method has no effect.
 *  If a custom UIView isn't supplied and barChartView:colorForBarViewAtIndex:  isn't implemented, then
 *  a gradient layer may be supplied to be used across all bars within the chart.
 *
 *  Default: black color.
 *
 *  @param barChartView     The bar chart object requesting this information.
 *
 *  @return The gradient layer to be used as a mask over all bars within the chart.
 */

最后,您可以使用barViewAtIndex:在每个条形基础上创建渐变,并返回带有渐变的自定义视图。

样品:

- (UIView *)barChartView:(JBBarChartView *)barChartView barViewAtIndex:(NSUInteger)index
{
    UIView *customBarView = [[UIView alloc] init];
    CAGradientLayer *gradient = [CAGradientLayer new];
    gradient.startPoint = CGPointMake(0.0, 0.0);
    gradient.endPoint = CGPointMake(1.0, 0.0);
    gradient.colors = @[(id)[UIColor redColor].CGColor, (id)[UIColor greenColor].CGColor];
    [customBarView.layer insertSublayer:gradient atIndex:0];
    return customBarView;
}

当然,customView应该是UIView的子类,你应该实现layoutSubviews来正确设置渐变的框架,但你明白了。