Question

我在iPhone应用程序中使用Core-Plot作为趋势图，但还没有找到如何自定义背景。我可以使用内置主题创建主题，如kCPPlainWhiteTheme，但我该如何更改它们？还是创建一个新的？

我基本上需要做的是让背景透明化。

编辑/更新

我测试了这段代码，但它似乎不起作用：

    //CPTheme *theme = [CPTheme themeNamed:kCPPlainWhiteTheme];
    CPTheme *theme = [[CPTheme alloc]init];
    chartTrend5 = (CPXYGraph *)[theme newGraph];    
    chartView.hostedGraph = chartTrend5;
    chartTrend5.paddingLeft = 0.0;
    chartTrend5.paddingTop = 0.0;
    chartTrend5.paddingRight = 0.0;
    chartTrend5.paddingBottom = 0.0;
    chartTrend5.fill = nil;
    chartTrend5.borderLineStyle = nil;
    chartView.hostedGraph.fill = nil;

    chartTrend5PlotSpace = (CPXYPlotSpace *)chartTrend5.defaultPlotSpace;
    chartTrend5PlotSpace.xRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(0)
                                                              length:CPDecimalFromFloat(5)];

    // range is 0-125, but since the frame heights is 90, 
    // we need to convert the points to this adjusted scale. The factor is 0.72 => (90/125)
    chartTrend5PlotSpace.yRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(0)
                                                              length:CPDecimalFromFloat(90)];



    CPXYAxisSet *axisSet = (CPXYAxisSet *)chartTrend5.axisSet;

    CPXYAxis *x = axisSet.xAxis;
    x.majorIntervalLength =  CPDecimalFromFloat(100);
    //x.constantCoordinateValue = CPDecimalFromFloat(2);
    x.minorTicksPerInterval = 2;
    x.borderWidth = 0;
    x.labelExclusionRanges = [NSArray arrayWithObjects:
                              [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(-1) 
                                                          length:CPDecimalFromFloat(800)], 
                              nil];;

    CPXYAxis *y = axisSet.yAxis;
    y.majorIntervalLength = CPDecimalFromFloat(100);
    y.minorTicksPerInterval = 1;
    //y.constantCoordinateValue = length:CPDecimalFromFloat(2);
    y.labelExclusionRanges = [NSArray arrayWithObjects:
                              [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(-26) 
                                                          length:CPDecimalFromFloat(100)], 
                              nil];





    CPScatterPlot *dataSourceLinePlot = [[[CPScatterPlot alloc] init] autorelease];
    dataSourceLinePlot.identifier = @"TrendChart";
    dataSourceLinePlot.dataLineStyle.lineWidth = 2.f;
    dataSourceLinePlot.dataLineStyle.lineColor = [CPColor colorWithComponentRed:(16/255.f) 
                                                                          green:(101/255.f) 
                                                                           blue:(122/255.f) 
                                                                          alpha:1];
    dataSourceLinePlot.dataSource = self;
    [chartTrend5 addPlot:dataSourceLinePlot];
    chartTrend5.fill = nil;
    // Put an area gradient under the plot above

    CPColor *areaColor = [CPColor colorWithComponentRed:(212/255.f) 
                                                  green:(233/255.f)
                                                   blue:(216/255.f)
                                                  alpha:1];

    CPGradient *areaGradient = [CPGradient gradientWithBeginningColor:areaColor 
                                                          endingColor:areaColor];
    areaGradient.angle = -90.0f;
    CPFill *areaGradientFill = [CPFill fillWithGradient:areaGradient];
    dataSourceLinePlot.areaFill = areaGradientFill;
    dataSourceLinePlot.areaBaseValue = CPDecimalFromString(@"5.25");

这里我将 CPXYGraph * chartTrend5 和 * CPXYPlotSpace * chartTrend5PlotSpace 的填充属性设置为nil。

Answer 1

除了Eric建议的内容外，您还可以尝试将填充设置为清晰的颜色。例如，我过去曾使用过这个来为图表提供透明背景：

CPTTheme *theme = [CPTTheme themeNamed:kCPPlainWhiteTheme];
graph = (CPTXYGraph *)[theme newGraph];

graph.fill = [CPTFill fillWithColor:[CPTColor clearColor]];
graph.plotAreaFrame.fill = [CPTFill fillWithColor:[CPTColor clearColor]];

Answer 2

主题只是一次设置大量样式属性的便捷方式。您可以单独设置其中任何一个以自定义外观。只要您希望区域透明，就可以将其填充设置为nil。与线条样式相同 - 将它们设置为nil以防止绘制线条。

您可能会关注两个“背景”区域。图形具有填充，绘图区域也是如此。绘图区域是绘制绘图的区域。将fill属性设置为nil以使背景透明。

Answer 3

我试过这个＆amp;它对我有用：

// Here 'hostingView' is your CPTGraphHostingView to
// which you add your graph
UIImageView *backgroundImage = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"background.png"]];
[hostingView addSubview:backgorundImage];
[hostingView sendSubviewToBack:backgroundImage];

Answer 4

我使用了.fill和.plot.AreaFrame.fill属性：

plot = [[CPTXYGraph alloc] initWithFrame:CGRectZero];
CPTTheme *theme = [CPTTheme themeNamed:kCPTSlateTheme];
[plot applyTheme:theme];
self.graph.collapsesLayers = NO;
self.graph.hostedGraph = plot;

plot.paddingLeft = 1.0;
plot.paddingTop = 1.0;
plot.paddingRight = 1.0;
plot.paddingBottom = 1.0;
plot.fill = [CPTFill fillWithColor:[CPTColor clearColor]];
plot.plotAreaFrame.fill = [CPTFill fillWithColor:[CPTColor clearColor]];

这适合我。

核心情节定制主题？

4 个答案: