Question

我有两节课。我试图从数据库值绘制图表但是我无法将值从一个类发送到另一个类，其中使用了数组。请仔细阅读我的代码并帮助我。

以下是存在数组值的类（现在我正在使用静态值）

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.achartengine.chartdemo.demo.chart.IDemoChart;
import org.achartengine.chartdemo.demo.chart.TemperatureChart;
import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class ChartDemo extends ListActivity {
    double a = 10;
    double pass[] = { 7, 0, 4, 8, 3, 5, 7, 6, 8, 19, 11, 4 };
    Intent intent;
    private IDemoChart[] mCharts = new IDemoChart[] { new TemperatureChart() };

    private String[] mMenuText;

    private String[] mMenuSummary;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        int length = mCharts.length;
        mMenuText = new String[length];
        mMenuSummary = new String[length];

        TemperatureChart obj=new TemperatureChart();
        obj.getArray(pass);
        for(int i=0;i<pass.length;i++)
        {
            Log.i("sanket",pass[i]+"");
        }

        for (int i = 0; i < length; i++) {
            mMenuText[i] = mCharts[i].getName();
            mMenuSummary[i] = mCharts[i].getDesc();
        }
        setListAdapter(new SimpleAdapter(this, getListValues(),
                android.R.layout.simple_list_item_2, new String[] {
                        IDemoChart.NAME, IDemoChart.DESC }, new int[] {
                        android.R.id.text1, android.R.id.text2 }));
    }

    private List<Map<String, String>> getListValues() {
        List<Map<String, String>> values = new ArrayList<Map<String, String>>();
        int length = mMenuText.length;
        for (int i = 0; i < length; i++) {
            Map<String, String> v = new HashMap<String, String>();
            v.put(IDemoChart.NAME, mMenuText[i]);
            v.put(IDemoChart.DESC, mMenuSummary[i]);
            values.add(v);
        }
        return values;
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);

        // intent = new Intent(this, TemperatureChart.class);

        // if (position <= mCharts.length + 1) {

        intent = mCharts[position].execute(this);

        // intent.putExtra("sam", a);
        // Log.i("sanket",a+"");

        // }

        startActivity(intent);
    }
}

现在这是我想要那些数组值的第二个类问题是这个类在填充数组中的那些项之前被初始化，所以这个类中的数组是空的

package org.achartengine.chartdemo.demo.chart;

import org.achartengine.ChartFactory;
import org.achartengine.chart.BarChart.Type;
import org.achartengine.model.RangeCategorySeries;
import org.achartengine.model.XYMultipleSeriesDataset;
import org.achartengine.renderer.SimpleSeriesRenderer;
import org.achartengine.renderer.XYMultipleSeriesRenderer;

import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.Paint.Align;
import android.util.Log;

/**
 * Temperature demo range chart.
 */
public class TemperatureChart implements IDemoChart {
    // static double b;

    double[] maxValues;

    public void getArray(double array1[]) {

        array1 = new double[12];
        this.maxValues = array1;

        for(int i=0;i<array1.length;i++)
        {
            Log.i("sanket",maxValues[i]+"");
        }
    }


    /**
     * Returns the chart name.
     * 
     * @return the chart name
     */
    public String getName() {
        return "MarkS range chart";
    }

    /**
     * Returns the chart description.
     * 
     * @return the chart description
     */
    public String getDesc() {
        return "The monthly Marks (vertical range chart)";
    }

    /**
     * Executes the chart demo.
     * 
     * @param context
     *            the context
     * @return the built intent
     */
    public Intent execute(Context context) {





        // b = getIntent().getIntExtra("sam", 0);
        // Log.i("sanket",b+"");
        double[] minValues = new double[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
        // double[] maxValues = new double[] { 7, 0, 4, 8, 3, 5, 7, 6, 8, 19,
        // 11,
        // 4 };

        XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
        RangeCategorySeries series = new RangeCategorySeries("Marks");
        int length = minValues.length;
        for (int k = 0; k < length; k++) {
            series.add(minValues[k], maxValues[k]);
        }
        dataset.addSeries(series.toXYSeries());
        int[] colors = new int[] { Color.CYAN };
        XYMultipleSeriesRenderer renderer = buildBarRenderer(colors);
        setChartSettings(renderer, "Monthly Marks range", "Month",
                "Marks Obtained", 0.5, 12.5, 0, 20, Color.GRAY, Color.LTGRAY);
        renderer.setBarSpacing(0.5);
        renderer.setXLabels(0);
        renderer.setYLabels(10);
        renderer.addXTextLabel(1, "Jan");
        renderer.addXTextLabel(3, "Mar");
        renderer.addXTextLabel(5, "May");
        renderer.addXTextLabel(7, "Jul");
        renderer.addXTextLabel(10, "Oct");
        renderer.addXTextLabel(12, "Dec");
        renderer.addYTextLabel(5, "OK");
        renderer.addYTextLabel(10, "GOOD");
        renderer.addYTextLabel(20, "Nice");
        renderer.setMargins(new int[] { 30, 70, 10, 0 });
        renderer.setYLabelsAlign(Align.RIGHT);
        SimpleSeriesRenderer r = renderer.getSeriesRendererAt(0);
        r.setDisplayChartValues(true);
        r.setChartValuesTextSize(12);
        r.setChartValuesSpacing(3);
        r.setGradientEnabled(true);
        r.setGradientStart(-20, Color.BLUE);
        r.setGradientStop(20, Color.GREEN);
        return ChartFactory.getRangeBarChartIntent(context, dataset, renderer,
                Type.DEFAULT, "Marks Range");
    }

    protected void setChartSettings(XYMultipleSeriesRenderer renderer,
            String title, String xTitle, String yTitle, double xMin,
            double xMax, double yMin, double yMax, int axesColor,
            int labelsColor) {
        renderer.setChartTitle(title);
        renderer.setXTitle(xTitle);
        renderer.setYTitle(yTitle);
        renderer.setXAxisMin(xMin);
        renderer.setXAxisMax(xMax);
        renderer.setYAxisMin(yMin);
        renderer.setYAxisMax(yMax);
        renderer.setAxesColor(axesColor);
        renderer.setLabelsColor(labelsColor);
    }

    protected XYMultipleSeriesRenderer buildBarRenderer(int[] colors) {
        XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();
        renderer.setAxisTitleTextSize(16);
        renderer.setChartTitleTextSize(20);
        renderer.setLabelsTextSize(15);
        renderer.setLegendTextSize(15);
        int length = colors.length;
        for (int i = 0; i < length; i++) {
            SimpleSeriesRenderer r = new SimpleSeriesRenderer();
            r.setColor(colors[i]);
            renderer.addSeriesRenderer(r);
        }
        return renderer;
    }
}

Answer 1

您可以使用静态变量和方法解决问题。将要共享的变量设置为静态。也可以在同一个类中编写静态方法来获取它。并从另一个类访问该方法。您可以在此处查看示例： - http://www.daniweb.com/software-development/java/threads/326941/passing-data-between-classes。

Answer 2

不知道你在这做什么：

public void getArray(double array1[]) {

    array1 = new double[12];
    this.maxValues = array1;

    for(int i=0;i<array1.length;i++)
    {
        Log.i("sanket",maxValues[i]+"");
    }
}

你用新的double [12]覆盖输入参数array1，因此覆盖了.maxValues。

Answer 3

//Create a public class:
public class Values{

public static int[] val = null;

}


//Set array in one class:
Values.val = int[] arr1;//arr1 containing your values


//Get array in another class:
int[] arr2 = Values.val;

Answer 4

如果将数组转换为int arraylist然后在活动之间传递它然后将其转换回另一个活动中的数组会更好。

将整数数组从一个类传递到另一个类

4 个答案: