缺少积分的区域（Area with missing points）

以下是缺少值的区域图的示例

我们已经在Google Charts Configuration Syntax一章中看到了用于绘制图表的配置 。 现在，让我们看一个缺少值的区域图的示例。

例子 (Example)

HelloWorld.java

package cn.xnip.client;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.RootPanel;
import com.googlecode.gwt.charts.client.ChartLoader;
import com.googlecode.gwt.charts.client.ChartPackage;
import com.googlecode.gwt.charts.client.ColumnType;
import com.googlecode.gwt.charts.client.DataTable;
import com.googlecode.gwt.charts.client.corechart.AreaChart;
import com.googlecode.gwt.charts.client.corechart.AreaChartOptions;
import com.googlecode.gwt.charts.client.options.HAxis;
import com.googlecode.gwt.charts.client.options.VAxis;
public class HelloWorld implements EntryPoint {
   private AreaChart chart;
   private void initialize() {
      ChartLoader chartLoader = new ChartLoader(ChartPackage.CORECHART);
      chartLoader.loadApi(new Runnable() {
         public void run() {
            // Create and attach the chart
            chart = new AreaChart();
            RootPanel.get().add(chart);
            draw();
         }
      });
   }
   private void draw() {
      // Prepare the data
      DataTable data = DataTable.create();
      data.addColumn(ColumnType.STRING, "Year");
      data.addColumn(ColumnType.NUMBER, "Sales");
      data.addColumn(ColumnType.NUMBER, "Expenses");
      data.addRow("2013", 1000, 400);
      data.addRow("2014", 1170, 460);
      data.addRow("2015", null, 1120);
      data.addRow("2016", 1030, 540);    		
      // Set options
      AreaChartOptions options = AreaChartOptions.create();
      options.setTitle("Company Performance");
      options.setIsStacked(true);
      options.setHAxis(HAxis.create("Year"));
      VAxis vAxis = VAxis.create();
      vAxis.setMinValue(0);
      options.setVAxis(vAxis);
      // Draw the chart
      chart.draw(data,options);
      chart.setWidth("400px");
      chart.setHeight("400px");
   }
   public void onModuleLoad() {
      initialize();
   }
}

结果 (Result)

验证结果。