ios - 核心剧情: axis alternatingBandFills with custom axis labels

Question

我正在使用 Core Plot 库在 iOS 上绘制图形。我想在 yAxis 的网格线之间添加颜色。我已经设法通过设置轴的 alternatingBandFills 属性来做到这一点。但是，我也必须在 yAxis 上使用自定义标签，并且当我提供自定义标签时，alternatingBandFills 属性由于某种原因不起作用。

任何有关如何为 y 轴上的网格线之间的空间添加颜色以及使用自定义标签的帮助将不胜感激。

我现在使用的代码如下所示:

    CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.hostedGraph.axisSet;
    CPTXYAxis *yAxis = axisSet.yAxis; 

    yAxis.orthogonalCoordinateDecimal = CPTDecimalFromDouble(minValueX);        
    yAxis.labelingPolicy = CPTAxisLabelingPolicyNone;

    NSArray *yAxisTickLocations = [NSArray arrayWithObjects:
                                   [NSDecimalNumber numberWithDouble:lowerRedRangeFrom],
                                   [NSDecimalNumber numberWithDouble:lowerOrangeRangeFrom],
                                   [NSDecimalNumber numberWithDouble:greenRangeFrom],
                                   [NSDecimalNumber numberWithDouble:upperOrangeRangeFrom],
                                   [NSDecimalNumber numberWithDouble:upperRedRangeFrom],
                                   [NSDecimalNumber numberWithDouble:upperRedRangeTo],
                                   nil];
    NSArray *yAxisLabels = [NSArray arrayWithObjects:@"Label1",@"Label2", @"Label3",@"Label4",@"Label5",@"Label6", nil];

    NSUInteger labelLocationY = 0;
    NSMutableArray *customLabelsY = [NSMutableArray arrayWithCapacity:[yAxisLabels count]];
    for (NSNumber *tickLocation in yAxisTickLocations) {

        CPTAxisLabel *newLabel = [[CPTAxisLabel alloc] initWithText: [yAxisLabels objectAtIndex:labelLocationY++] textStyle:axisSet.xAxis.labelTextStyle];
        newLabel.tickLocation = [tickLocation decimalValue];
        newLabel.offset = axisSet.xAxis.labelOffset + axisSet.xAxis.majorTickLength;
        newLabel.rotation = M_PI/4;
        [customLabelsY addObject:newLabel];
    }

    axisSet.yAxis.axisLabels =  [NSSet setWithArray:customLabelsY];
    yAxis.alternatingBandFills = [NSArray arrayWithObjects:
                                  [CPTColor redColor],
                                  [CPTColor orangeColor],
                                  [CPTColor greenColor],
                                  [CPTColor orangeColor],
                                  [CPTColor redColor], nil];

Answer 1

我想通了:

轴的标签策略应该是:CPTAxisLabelingPolicyLocationsProvided，文档指出:“用户设置刻度位置；轴制作标签。”。

现在我们只需要指定刻度的位置。这是通过创建一个包含位置的 NSSet 对象来完成的。然后我们必须设置轴的 majorTickLocations 属性。

所以我的代码现在看起来像:

    CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.hostedGraph.axisSet;
    CPTXYAxis *yAxis = axisSet.yAxis;

    yAxis.orthogonalCoordinateDecimal = CPTDecimalFromDouble(minValueX);        
    yAxis.labelingPolicy = CPTAxisLabelingPolicyLocationsProvided;

    NSSet *majorTickLocations = [NSSet setWithObjects:
                                 [NSDecimalNumber numberWithDouble:lowerRedRangeFrom],
                                 [NSDecimalNumber numberWithDouble:lowerOrangeRangeFrom],
                                 [NSDecimalNumber numberWithDouble:greenRangeFrom],
                                 [NSDecimalNumber numberWithDouble:upperOrangeRangeFrom],
                                 [NSDecimalNumber numberWithDouble:upperRedRangeFrom],
                                 [NSDecimalNumber numberWithDouble:upperRedRangeTo],
                                 nil];
    yAxis.majorTickLocations = majorTickLocations;

    yAxis.alternatingBandFills = [NSArray arrayWithObjects:
                                  [CPTColor redColor],
                                  [CPTColor orangeColor],
                                  [CPTColor greenColor],
                                  [CPTColor orangeColor],
                                  [CPTColor redColor], nil];