基本步骤图表（Basic Stepped Chart）

以下是步进图表的示例。

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，让我们看一个阶梯图的示例。

配置 (Configurations)

我们使用ScatterChart类来显示阶梯图。

SteppedChart chart = new SteppedChart();

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.SteppedAreaChart;
import com.googlecode.gwt.charts.client.corechart.SteppedAreaChartOptions;
import com.googlecode.gwt.charts.client.options.VAxis;
public class HelloWorld implements EntryPoint {
   private SteppedAreaChart chart;
   private void initialize() {
      ChartLoader chartLoader = new ChartLoader(ChartPackage.CORECHART);
      chartLoader.loadApi(new Runnable() {
         public void run() {
            // Create and attach the chart
            chart = new SteppedAreaChart();
            RootPanel.get().add(chart);
            draw();
         }
      });
   }
   private void draw() {
      // Prepare the data
      DataTable data = DataTable.create();
      data.addColumn(ColumnType.STRING, "Director (Year)");
      data.addColumn(ColumnType.NUMBER, "Rotten Tomatoes");
      data.addColumn(ColumnType.NUMBER, "IMDB");
      data.addRow("Alfred Hitchcock (1935)", 8.4, 7.9);
      data.addRow("Ralph Thomas (1959)",     6.9,         6.5);
      data.addRow("Don Sharp (1978)",        6.5,         6.4);
      data.addRow("James Hawes (2008)",      4.4,         6.2);
      SteppedAreaChartOptions options  = SteppedAreaChartOptions.create();
      options.setTitle("The decline of 'The 39 Steps'");
      VAxis vAxis = VAxis.create();
      vAxis.setTitle("Accumulated Rating");
      // Draw the chart
      chart.draw(data, options);
      chart.setWidth("400px");
      chart.setHeight("400px");
   }
   public void onModuleLoad() {
      initialize();
   }
}

结果 (Result)

验证结果。