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我正在使用 achartengine 制作一个 LineGraph 类。问题是我无法从数据库中导入数据。我想将两个 int 数据库列添加到 int 系列中。我怎么做？这是我到目前为止所拥有的：

package com.weightmaster.awesome.development.chart;

import org.achartengine.ChartFactory;
import org.achartengine.chart.PointStyle;
import org.achartengine.model.TimeSeries;
import org.achartengine.model.XYMultipleSeriesDataset;
import org.achartengine.renderer.XYMultipleSeriesRenderer;
import org.achartengine.renderer.XYSeriesRenderer;

import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Color;
import android.util.Log;

import com.weightmaster.awesome.development.WeightMasterOverviewActivity;
import com.weightmaster.awesome.development.database.WMSQLiteHelper;

public class LineGraph {


public static SQLiteDatabase dbSqlite;
public static WMSQLiteHelper helper;

public static XYMultipleSeriesDataset getDemoDataset(String title) {

    Log.d(WeightMasterOverviewActivity.TAG, "Kjører metoden1");

    Cursor cursor = helper.getDateAsc();
    XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();

    TimeSeries series = new TimeSeries("Line1");
    TimeSeries series2 = new TimeSeries(title);

    Log.d(WeightMasterOverviewActivity.TAG, "Kjører metoden");
    cursor.moveToFirst();
    Log.d(WeightMasterOverviewActivity.TAG,
            "Cursoren flyttet til første element");
    while (!cursor.isAfterLast()) {
        int date = cursor.getInt((Integer) cursor.getColumnIndexOrThrow("date"));
        Log.d(WeightMasterOverviewActivity.TAG, "Legger til dato");

        int weight = cursor.getInt((Integer) cursor.getColumnIndexOrThrow("weight"));
        Log.d(WeightMasterOverviewActivity.TAG, "Legger til vekt");
        series2.add(weight, date);
        cursor.moveToNext();
        Log.d(WeightMasterOverviewActivity.TAG,
                "Cursoren flyttet til neste element");
    }
    Log.d(WeightMasterOverviewActivity.TAG,
            "There were no values in the cursor.");
    cursor.close();

    Log.d(WeightMasterOverviewActivity.TAG, "Den når til enden");
    dataset.addSeries(series);

    dataset.addSeries(series2);

    return dataset;
}

public Intent getIntent(Context context) {

    //Lager TimeSeries for den første linja


    XYMultipleSeriesDataset dataset = getDemoDataset("Line1");

    //Kode for render
    XYMultipleSeriesRenderer mRenderer = new XYMultipleSeriesRenderer();

    //Optimalisering linje1
    XYSeriesRenderer renderer = new XYSeriesRenderer();
    renderer.setColor(Color.YELLOW);
    renderer.setPointStyle(PointStyle.CIRCLE);
    renderer.setFillPoints(true);

    // Optimalisering linje2 husk rekke følgen
    XYSeriesRenderer renderer2 = new XYSeriesRenderer();
    renderer2.setColor(Color.BLUE);
    renderer2.setPointStyle(PointStyle.SQUARE);
    renderer2.setFillPoints(true);

    //Legger til render seriene
    mRenderer.addSeriesRenderer(renderer);

    //Optimalisering grafen
    mRenderer.setChartTitle("Test");
    mRenderer.setZoomEnabled(true);
    mRenderer.setZoomButtonsVisible(true);
    mRenderer.setBackgroundColor(Color.BLACK);
    mRenderer.setApplyBackgroundColor(true);
    mRenderer.setXTitle("Dager");
    mRenderer.setShowGrid(true);

    mRenderer.addSeriesRenderer(renderer2);


    Intent intent = ChartFactory.getLineChartIntent(context, dataset, 
            mRenderer, "Line Graph Title");

    return intent;

}
}

它在调试器中的以下行停止：

Cursor cursor = helper.getDateAsc();
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1 回答 1

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您将需要创建一个新的 WMSQLiteHelper。现在它是空的。我不知道你的助手的参数是什么，但它应该看起来像这样。

helper = new WMSQLiteHelper(this);

放在上面

Cursor cursor = helper.getDateAsc();
于 2012-03-26T05:38:14.793 回答