JFreeChart BarChart -> NO gradient

问题:

my bar chart is always drawn with a gradient color by default. I just want a simple color without any styled effects.

Can anyone help ?

Code:

   final JFreeChart chart = ChartFactory.createBarChart(         "",         // chart title         xLabel,               // domain axis label         yLabel,                  // range axis label         dataset,                  // data         PlotOrientation.VERTICAL, // orientation         true,                     // include legend         false,                     // tooltips?         false                     // URLs?     );    final CategoryPlot plot = chart.getCategoryPlot();   // SOMETHING HAS TO BE DONE HERE    showChart(chart); // Simply shows the chart in a new window 

Thanks

回答1:

The problem lies in the BarPainter you are using. The JFreeChart version 1.0.13 default is to use GradientBarPainter which adds a metallic-ish look to the bar. If you want the "old" look the solution is to use the StandardBarPainter.

final CategoryPlot plot = chart.getCategoryPlot(); ((BarRenderer) plot.getRenderer()).setBarPainter(new StandardBarPainter()); 

That should do it.

Alternatively, if you want use JFreeChart's BarRenderer, you could force it to use the StandardBarPainter by calling the static method setDefaultBarPainter() before initializing your renderer.

final CategoryPlot plot = chart.getCategoryPlot(); BarRenderer.setDefaultBarPainter(new StandardBarPainter()); ((BarRenderer) plot.getRenderer()).setBarPainter(new BarPainter()); 

If you want more control of the chart you can always build it from the ground up instead of using ChartFactory, but that does require a lot extra code.

回答2:

Before you create the chart from ChartFactory you can set the chart theme:

ChartFactory.setChartTheme(StandardChartTheme.createLegacyTheme()); 

The default is the JFreeTheme which adds the gradient. The following themes are available:

ChartFactory.setChartTheme(StandardChartTheme.createJFreeTheme()); ChartFactory.setChartTheme(StandardChartTheme.createDarknessTheme()); 

回答3:

The source code for org.jfree.chart.demo.BarChartDemo1 shows how to set the series colors. Just specify plain colors instead of gradients.

renderer.setSeriesPaint(0, Color.red); renderer.setSeriesPaint(1, Color.green); renderer.setSeriesPaint(2, Color.blue); 

Correction: The key to @Jes's helpful answer may be found in the initialization of defaultBarPainter in BarRenderer.

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