ios - JBChartView 中未显示条形图的颜色

Question

我正在尝试在我的 iOS 应用中实现条形图。我正在使用 JBChartView。一切正常，但条形图没有颜色，除非我使用 touchEvent 按下它们。

有没有人有使用这个特定插件的经验来帮助我让它正常工作？

谢谢

  - (void)viewDidLoad
    {


       _barChartView = [[JBBarChartView alloc] init];
        _barChartView.delegate = self;
        _barChartView.dataSource = self;


    _tableView.backgroundColor =[UIColor clearColor];
        _barChartView.frame = CGRectMake(0,0,200,200);
        _barChartView.backgroundColor = [UIColor clearColor];
        [_barChartView reloadData];
        [_barChart addSubview: _barChartView];

    }


    - (UIColor *)barSelectionColorForBarChartView:(JBBarChartView *)barChartView
    {
        return [UIColor greenColor]; // color of selection view
    }
    - (BOOL)slideNavigationControllerShouldDisplayLeftMenu
    {
        return YES;
    }
    - (UIColor *)barChartView:(JBBarChartView *)barChartView colorForBarViewAtIndex:(NSUInteger)index
    {
        return [UIColor greenColor];
    }

    - (NSUInteger)numberOfBarsInBarChartView:(JBBarChartView *)barChartView
    {
        return 4;
    }
    - (CGFloat)barChartView:(JBBarChartView *)barChartView heightForBarViewAtAtIndex:(NSUInteger)index
    {
        return 100.0;
    }

Answer 1

问题似乎在于 JBBarChartView 如何“规范化”这些值。根据 JBBarChartView.h 的头文件:

/**
 *  Height for a bar at a given index (left to right). There is no ceiling on the the height; 
 *  the chart will automatically normalize all values between the overal min and max heights.
 *
 *  @param barChartView     The bar chart object requesting this information.
 *  @param index            The 0-based index of a given bar (left to right, x-axis).
 *
 *  @return The y-axis height of the supplied bar index (x-axis)
 */

由于这种“规范化”，当您的所有值都相同时 (100.0f)，它会将它们全部规范化为 0，因此没有要显示的栏。幸运的是，它是开源的，所以你只需要打开实现文件并做一点修改:

- (CGFloat)normalizedHeightForRawHeight:(NSNumber*)rawHeight
{
    CGFloat minHeight = [self minimumValue];
    CGFloat maxHeight = [self maximumValue];
    CGFloat value = [rawHeight floatValue];

    if ((maxHeight - minHeight) <= 0)
    {
        return self.availableHeight; // change this line to return the max height instead of 0
    }

    return ((value - minHeight) / (maxHeight - minHeight)) * [self availableHeight];
}