CorePlot：创建宽度可变的波段（根据数据变化）

Question

我想创建一个带有动态波段的 CorePlot 图（随着时间的推移而变化），有点像这里的这张丑陋的图画（请原谅我质量）：

基本上，波段颜色应根据某些值/标准而改变。黄色带可以更宽或更细，白色和绿色带也可以。 换句话说，这些波段需要具有动态宽度

这是我设置 y 图表带着色的当前方式，但是如果我动态更改它，它不起作用，因为它会全部更改（我只想在图表的特定区域动态更改带，而不是全部其中）。

知道如何实现这一目标吗？

这是与乐队相关的代码：

CPTFill *whitebandFill = [CPTFill fillWithColor:[[CPTColor whiteColor] colorWithAlphaComponent:0.5]];
CPTFill *greenbandFill = [CPTFill fillWithColor:[[CPTColor greenColor] colorWithAlphaComponent:0.5]];
CPTFill *redbandFill = [CPTFill fillWithColor:[[CPTColor redColor] colorWithAlphaComponent:0.75]];

 [y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(0.0) lengthDecimal:CPTDecimalFromDouble(500.0)] fill:whitebandFill]];
[y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(500.0) lengthDecimal:CPTDecimalFromDouble(750.0)] fill:greenbandFill]];

 [y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(750.0) lengthDecimal:CPTDecimalFromDouble(1024.0)] fill:redbandFill]];

这是我的完整当前源代码：

self.data = [[NSMutableArray alloc] initWithCapacity:100];
self.allData = [[NSMutableArray alloc] init];

// Create a CPTGraph object and add to hostView
self.graph = [[CPTXYGraph alloc] initWithFrame:self.graphHostView.bounds];
self.graphHostView.hostedGraph = self.graph;

CPTMutableTextStyle *titleStyle = [CPTMutableTextStyle textStyle];
titleStyle.color = [CPTColor blackColor];
titleStyle.fontName = @"Futura";
titleStyle.fontSize = 12.0f;

//////////
// Axes
// Label x axis with a fixed interval policy
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.graph.axisSet;
CPTXYAxis *x          = axisSet.xAxis;
x.separateLayers              = NO;
x.title                       = @"X Axis";
x.titleTextStyle              = titleStyle;

colorWithAlphaComponent:CPTFloat(0.1)], [[CPTColor greenColor] colorWithAlphaComponent:CPTFloat(0.1)]]; x.delegate = 自我；

CPTXYAxis *y = axisSet.yAxis;
y.labelingPolicy        = CPTAxisLabelingPolicyAutomatic;
y.separateLayers        = YES;
y.majorTickLocations = [NSSet setWithObjects:
                        [NSDecimalNumber numberWithDouble:0],
                        [NSDecimalNumber numberWithDouble:300],
                        nil];

y.title                 = @"Y Axis";
y.titleTextStyle        = titleStyle;

colorWithAlphaComponent:CPTFloat(0.3)], [NSNull null]]; y.delegate = self;

CPTFill *whitebandFill = [CPTFill fillWithColor:[[CPTColor whiteColor] colorWithAlphaComponent:0.5]];
CPTFill *greenbandFill = [CPTFill fillWithColor:[[CPTColor greenColor] colorWithAlphaComponent:0.5]];
CPTFill *redbandFill = [CPTFill fillWithColor:[[CPTColor redColor] colorWithAlphaComponent:0.75]];

 [y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(0.0) lengthDecimal:CPTDecimalFromDouble(500.0)] fill:whitebandFill]];
[y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(500.0) lengthDecimal:CPTDecimalFromDouble(750.0)] fill:greenbandFill]];

 [y addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:[CPTPlotRange plotRangeWithLocationDecimal:CPTDecimalFromDouble(750.0) lengthDecimal:CPTDecimalFromDouble(1024.0)] fill:redbandFill]];

self.graph.axisSet.axes = @[x, y];

Answer 1

限制带总是在地块上以直线延伸。您可以使用其他绘图来绘制更复杂的形状。设置areaFill 在绘图线和areaBaseValue 之间绘制填充。