java - 在布局中加载图表

Question

我尝试在布局中加载图形，使用 AChartEngine 的数学图形。我从该站点下载了一个演示 zip，我意识到我需要类似 sin-cosin grahp 样式的东西。所以，这是我写的代码:

    package com.myproject;
    import org.achartengine.ChartFactory;
    import org.achartengine.GraphicalView;
    import org.achartengine.chart.PointStyle;
    import org.achartengine.model.XYMultipleSeriesDataset;
    import org.achartengine.renderer.XYMultipleSeriesRenderer;
    import android.os.Bundle;
    import android.app.Activity;
    import android.content.Intent;
    import android.graphics.Color;
    import android.view.View;
    import android.webkit.WebView;
    import android.widget.LinearLayout;
    import android.widget.LinearLayout.LayoutParams;
    import com.myproject.clases.AbstractDemoChart;

    public class MainActivity extends Activity {

private WebView ventana;
private GraphicalView mChartView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    XYMultipleSeriesDataset mDataset = null;//this line causes runtime error but I will see this issue later.
            int [] colors = new int[] { Color.BLUE, Color.CYAN };
        PointStyle[] styles = new PointStyle[] { PointStyle.POINT, PointStyle.POINT };
        XYMultipleSeriesRenderer mRenderer = buildRenderer(colors, styles);
    LinearLayout layout = (LinearLayout) findViewById(R.id.chart);      
    mChartView = ChartFactory.getLineChartView(this, mDataset, mRenderer);
    layout.addView(mChartView, new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
}
}

但是线

    XYMultipleSeriesRenderer mRenderer = buildRenderer(colors, styles);

由于方法 buildRenderer() 属于 AbstractDemoChart 类而导致编译错误。我怎样才能将另一个类中的方法用于另一个类中？这可能是我知道的对象编程的一个基本问题，但我在这里问这个也是为了知道我是否打算在布局中加载 grahp 图表。我在 Eclipse 工作。谢谢

Answer 1

buildRenderer 是 AbstractDemoChart 中的 protected 方法。但是在AChartExampleActivity示例 buildRenderer 是执行此操作的私有(private)方法:

private XYMultipleSeriesRenderer buildRenderer(int[] colors,PointStyle[] styles) 
    {
        XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();
        setRenderer(renderer, colors, styles);
        return renderer;
    }

你见过GeneratedChartDemo吗？代码？它以这种方式创建渲染器:

private XYMultipleSeriesRenderer getDemoRenderer() {

    XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();
    renderer.setAxisTitleTextSize(16);
    renderer.setChartTitleTextSize(20);
    renderer.setLabelsTextSize(15);
    renderer.setLegendTextSize(15);
    renderer.setPointSize(5f);
    renderer.setMargins(new int[] {20, 30, 15, 0}); 
    ...

我认为您应该更改初始化 XYMultipleSeriesRenderer 的方式。