学习JFreeChart（一）(3)

這個範例中並沒有對JFreeChart作修飾。

   private JFreeChart customizeChart(final JFreeChart chart){

      return chart;

   }

第四步：顯示JFreeChart

ChartPanel是一個繼承JPanel的類別，負責把JFreeChart在應用程式中顯示出來。
我們只要把JFreeChart當成參數傳給ChartPanel的建構子。造出ChartPanel的實體後，設定大小，再當成一般的Panel放入ContentPane中就可以了。

ChartPanel class:

public ChartPanel(JFreeChart chart)

public ChartPanel(JFreeChart chart, boolean useBuffer)

public ChartPanel(JFreeChart chart,

                  boolean properties,

                  boolean save,

                  boolean print,

                  boolean zoom,

                  boolean tooltips)

public ChartPanel(JFreeChart chart,

                  int width,

                  int height,

                  int minimumDrawWidth,

                  int minimumDrawHeight,

                  int maximumDrawWidth,

                  int maximumDrawHeight,

                  boolean useBuffer,

                  boolean properties,

                  boolean save,

                  boolean print,

                  boolean zoom,

                  boolean tooltips)

chart - the chart.
useBuffer - a flag controlling whether or not an off-screen buffer is used.
properties - a flag indicating whether or not the chart property editor should be available via the popup menu.
save - a flag indicating whether or not save options should be available via the popup menu.
print - a flag indicating whether or not the print option should be available via the popup menu.
zoom - a flag indicating whether or not zoom options should be added to the popup menu.
tooltips - a flag indicating whether or not tooltips should be enabled for the chart.
width - the preferred width of the panel.
height - the preferred height of the panel.
minimumDrawWidth - the minimum drawing width.
minimumDrawHeight - the minimum drawing height.
maximumDrawWidth - the maximum drawing width.
maximumDrawHeight - the maximum drawing height.

   public HelloBarChart(){

      CategoryDataset dataset = createDataset();

      JFreeChart chart = createChart(dataset);

      chart = customizeChart(chart);

      ChartPanel chartPanel = new ChartPanel(chart);

      chartPanel.setPreferredSize(new Dimension(500, 270));

      getContentPane().add(chartPanel);



      pack();

      setVisible(true);

      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

   }