我已经设置了图表引擎，它运行良好，在尝试向图表添加另一个图表后，我在 log cat 上收到以下错误消息。代码中没有列表，尽管它是从 listactivity 扩展而来的。
代码有什么问题。
package org.achartengine.chartdemo.demo;
import java.text.Format;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.GregorianCalendar;
import org.achartengine.ChartFactory;
import org.achartengine.GraphicalView;
import org.achartengine.chart.PointStyle;
import org.achartengine.model.SeriesSelection;
import org.achartengine.model.TimeSeries;
import org.achartengine.model.XYMultipleSeriesDataset;
import org.achartengine.renderer.XYMultipleSeriesRenderer;
import org.achartengine.renderer.XYSeriesRenderer;
import android.annotation.SuppressLint;
import android.app.ListActivity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.Toast;
@SuppressLint("SimpleDateFormat")
public class ChartDemo extends ListActivity {
private GraphicalView mChart;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.xy_chart);
openChart();
}
private void openChart(){
int count = 5;
Date[] dt = new Date[5];
for(int i=0;i<count;i++){
GregorianCalendar gc = new GregorianCalendar(2012, 10, i+1);
dt[i] = gc.getTime();
}
int[] visits = { 2000,2500,2700,2100,2800};
int[] views = {2200, 2700, 2900, 2800, 3200};
int[] views3 = {2100, 2740, 2100, 2900, 3100};
// Creating TimeSeries for Visits
TimeSeries visitsSeries = new TimeSeries("Visits");
// Creating TimeSeries for Views
TimeSeries viewsSeries = new TimeSeries("Views");
TimeSeries viewsSeries3 = new TimeSeries("Views3");
// Adding data to Visits and Views Series
for(int i=0;i<dt.length;i++){
visitsSeries.add(dt[i], visits[i]);
viewsSeries.add(dt[i],views[i]);
viewsSeries3.add(dt[i],views3[i]);
}
// Creating a dataset to hold each series
XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
// Adding Visits Series to the dataset
dataset.addSeries(visitsSeries);
// Adding Visits Series to dataset
dataset.addSeries(viewsSeries);
dataset.addSeries(viewsSeries3);
// Creating XYSeriesRenderer to customize visitsSeries
XYSeriesRenderer visitsRenderer = new XYSeriesRenderer();
visitsRenderer.setColor(Color.WHITE);
visitsRenderer.setPointStyle(PointStyle.CIRCLE);
visitsRenderer.setFillPoints(true);
visitsRenderer.setLineWidth(2);
visitsRenderer.setDisplayChartValues(true);
// Creating XYSeriesRenderer to customize viewsSeries
XYSeriesRenderer viewsRenderer = new XYSeriesRenderer();
viewsRenderer.setColor(Color.YELLOW);
viewsRenderer.setPointStyle(PointStyle.CIRCLE);
viewsRenderer.setFillPoints(true);
viewsRenderer.setLineWidth(2);
viewsRenderer.setDisplayChartValues(true);
// Creating XYSeriesRenderer3 to customize viewsSeries
XYSeriesRenderer viewsRenderer3 = new XYSeriesRenderer();
viewsRenderer.setColor(Color.YELLOW);
viewsRenderer.setPointStyle(PointStyle.CIRCLE);
viewsRenderer.setFillPoints(true);
viewsRenderer.setLineWidth(2);
viewsRenderer.setDisplayChartValues(true);
// Creating a XYMultipleSeriesRenderer to customize the whole chart
XYMultipleSeriesRenderer multiRenderer = new XYMultipleSeriesRenderer();
multiRenderer.setChartTitle("Visits vs Views Chart");
multiRenderer.setXTitle("Days");
multiRenderer.setYTitle("Count");
multiRenderer.setZoomButtonsVisible(true);
// Adding visitsRenderer and viewsRenderer to multipleRenderer
// Note: The order of adding dataseries to dataset and renderers to multipleRenderer
// should be same
multiRenderer.addSeriesRenderer(visitsRenderer);
multiRenderer.addSeriesRenderer(viewsRenderer);
multiRenderer.addSeriesRenderer(viewsRenderer3);
// Getting a reference to LinearLayout of the MainActivity Layout
LinearLayout chartContainer = (LinearLayout) findViewById(R.id.chart_container);
// Creating a Time Chart
mChart = (GraphicalView) ChartFactory.getTimeChartView(getBaseContext(), dataset, multiRenderer,"dd-MMM-yyyy");
multiRenderer.setClickEnabled(true);
multiRenderer.setSelectableBuffer(10);
// Setting a click event listener for the graph
mChart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Format formatter = new SimpleDateFormat("dd-MMM-yyyy");
SeriesSelection seriesSelection = mChart.getCurrentSeriesAndPoint();
if (seriesSelection != null) {
int seriesIndex = seriesSelection.getSeriesIndex();
String selectedSeries="Visits";
if(seriesIndex==0)
selectedSeries = "Visits";
else
selectedSeries = "Views";
// Getting the clicked Date ( x value )
long clickedDateSeconds = (long) seriesSelection.getXValue();
Date clickedDate = new Date(clickedDateSeconds);
String strDate = formatter.format(clickedDate);
// Getting the y value
int amount = (int) seriesSelection.getValue();
// Displaying Toast Message
Toast.makeText(
getBaseContext(),
selectedSeries + " on " + strDate + " : " + amount ,
Toast.LENGTH_SHORT).show();
}
}
});
// Adding the Line Chart to the LinearLayout
chartContainer.addView(mChart);
}
// @Override
// public boolean onCreateOptionsMenu(Menu menu) {
// getMenuInflater().inflate(R., menu);
// return true;
// }
}
日志猫：
03-19 20:25:16.690: E/AndroidRuntime(753): FATAL EXCEPTION: main
03-19 20:25:16.690: E/AndroidRuntime(753): java.lang.RuntimeException: Unable to start activity ComponentInfo{org.achartengine.chartdemo.demo/org.achartengine.chartdemo.demo.ChartDemo}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
03-19 20:25:16.690: E/AndroidRuntime(753): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
03-19 20:25:16.690: E/AndroidRuntime(753): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
03-19 20:25:16.690: E/AndroidRuntime(753): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
03-19 20:25:16.690: E/AndroidRuntime(753): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
03-19 20:25:16.690: E/AndroidRuntime(753): at android.os.Looper.loop(Looper.java:123)
03-19 20:25:16.690: E/AndroidRuntime(753): at android.app.ActivityThread.main(ActivityThread.java:3683)
03-19 20:25:16.690: E/AndroidRuntime(753): at java.lang.reflect.Method.invokeNative(Native Method)
03-19 20:25:16.690: E/AndroidRuntime(753): at java.lang.reflect.Method.invoke(Method.java:507)
03-19 20:25:16.690: E/AndroidRuntime(753): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
03-19 20:25:16.690: E/AndroidRuntime(753): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
03-19 20:25:16.690: E/AndroidRuntime(753): at dalvik.system.NativeStart.main(Native Method)
03-19 20:25:16.690: E/AndroidRuntime(753): Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
03-19 20:25:16.690: E/AndroidRuntime(753): at android.app.ListActivity.onContentChanged(ListActivity.java:243)
03-19 20:25:16.690: E/AndroidRuntime(753): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:210)
03-19 20:25:16.690: E/AndroidRuntime(753): at android.app.Activity.setContentView(Activity.java:1657)
03-19 20:25:16.690: E/AndroidRuntime(753): at org.achartengine.chartdemo.demo.ChartDemo.onCreate(ChartDemo.java:47)
03-19 20:25:16.690: E/AndroidRuntime(753): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
03-19 20:25:16.690: E/AndroidRuntime(753): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
03-19 20:25:16.690: E/AndroidRuntime(753): ... 11 more
这是xml代码
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/tv_title"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/str_tv_title"
android:gravity="center_horizontal" />
<LinearLayout
android:id="@+id/chart_container"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/tv_title" >
</LinearLayout>
</RelativeLayout>