GWT Google Charts 多级桑基图

以下是多级桑基图的示例。

我们已经在《GWT Google Charts 入门程序》章节中看到了用于绘制图表的基本步骤。现在，让我们看一个多级桑基图的例子。

GWT Google Charts 多级桑基图 配置

我们使用Sankey类来显示具有多个级别的桑基图图表。

Sankey chart = new Sankey();

GWT Google Charts 多级桑基图 示例

package com.yiidian.helloWorld.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.*;
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.sankey.Sankey;

public class HelloWorld implements EntryPoint {
    private Sankey chart;

    private void initialize() {
        ChartLoader chartLoader = new ChartLoader(ChartPackage.SANKEY);
        chartLoader.loadApi(new Runnable() {
            public void run() {
                // Create and attach the chart
                chart = new Sankey();
                RootPanel.get().add(chart);
                draw();
            }
        });
    }
    private void draw() {
        // Prepare the data
        DataTable data = DataTable.create();
        data.addColumn(ColumnType.STRING, "From");
        data.addColumn(ColumnType.STRING, "To");
        data.addColumn(ColumnType.NUMBER, "Weight");

        data.addRow("Brazil","Portugal",5);
        data.addRow("Brazil","France",1 );
        data.addRow("Brazil","Spain",1 );
        data.addRow("Brazil","England",1 );
        data.addRow("Canada","Portugal",1 );
        data.addRow("Canada","France",5 );
        data.addRow("Canada","England",1 );
        data.addRow("Mexico","Portugal",1 );
        data.addRow("Mexico","France",1 );
        data.addRow("Mexico","Spain",5 );
        data.addRow("Mexico","England",1 );
        data.addRow("USA","Portugal",1 );
        data.addRow("USA","France",1 );
        data.addRow("USA","Spain",1 );
        data.addRow("USA","England",5);
        data.addRow("Portugal","Angola", 2 );
        data.addRow("Portugal","Senegal", 1 );
        data.addRow("Portugal", "Morocco", 1 );
        data.addRow("Portugal","South Africa", 3 );

        // Draw the chart
        chart.draw(data);
        chart.setWidth("600px");
        chart.setHeight("400px");
    }
    public void onModuleLoad() {
        initialize();
    }
}

输出结果为：