android - 在 Android 中创建图表

Question

我正在尝试在 Android 中创建折线图。我使用了 achartengine-1.1.0.jar。但是当我尝试启动时，图表未显示。请帮忙。这是代码。

主 Activity .java

 package com.example.linecharts;

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

    import android.graphics.Color;
    import android.os.Bundle;
    import android.support.v4.app.Fragment;
    import android.support.v7.app.ActionBarActivity;
    import android.view.LayoutInflater;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.LinearLayout;

    public class MainActivity extends ActionBarActivity {

         private View mChart;

            private String[] mMonth = new String[] {
                "Jan", "Feb" , "Mar", "Apr", "May", "Jun",
                "Jul", "Aug" , "Sep", "Oct", "Nov", "Dec"
            };

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

        private void openChart()
        {
            int[] x = { 1,2,3,4,5,6,7,8 };
            int[] income = { 2000,2500,2700,3000,2800,3500,3700,3800};
            int[] expense = {2200, 2700, 2900, 2800, 2600, 3000, 3300, 3400 };

         // Creating an  XYSeries for Income
            XYSeries incomeSeries = new XYSeries("Income");
            // Creating an  XYSeries for Expense
            XYSeries expenseSeries = new XYSeries("Expense");
            // Adding data to Income and Expense Series
            for(int i=0;i<x.length;i++)
            {
                incomeSeries.add(x[i], income[i]);
                expenseSeries.add(x[i],expense[i]);
            }

         // Creating a dataset to hold each series
            XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
            // Adding Income Series to the dataset
            dataset.addSeries(incomeSeries);
            // Adding Expense Series to dataset
            dataset.addSeries(expenseSeries);

         // Creating XYSeriesRenderer to customize incomeSeries
            XYSeriesRenderer incomeRenderer = new XYSeriesRenderer();
            incomeRenderer.setColor(Color.WHITE);
            incomeRenderer.setPointStyle(PointStyle.CIRCLE);
            incomeRenderer.setFillPoints(true);
            incomeRenderer.setLineWidth(2);
            incomeRenderer.setDisplayChartValues(true);

         // Creating XYSeriesRenderer to customize expenseSeries
            XYSeriesRenderer expenseRenderer = new XYSeriesRenderer();
            expenseRenderer.setColor(Color.YELLOW);
            expenseRenderer.setPointStyle(PointStyle.CIRCLE);
            expenseRenderer.setFillPoints(true);
            expenseRenderer.setLineWidth(2);
            expenseRenderer.setDisplayChartValues(true);

         // Creating a XYMultipleSeriesRenderer to customize the whole chart
            XYMultipleSeriesRenderer multiRenderer = new XYMultipleSeriesRenderer();
            multiRenderer.setXLabels(0);
            multiRenderer.setChartTitle("Income vs Expense Chart");
            multiRenderer.setXTitle("Year 2012");
            multiRenderer.setYTitle("Amount in Dollars");
            multiRenderer.setZoomButtonsVisible(true);
            for(int i=0;i<x.length;i++)
            {
                multiRenderer.addXTextLabel(i+1, mMonth[i]);
            }

         // Adding incomeRenderer and expenseRenderer to multipleRenderer
            // Note: The order of adding dataseries to dataset and renderers to multipleRenderer
            // should be same
            multiRenderer.addSeriesRenderer(incomeRenderer);
            multiRenderer.addSeriesRenderer(expenseRenderer);

            // Getting a reference to LinearLayout of the MainActivity Layout
            LinearLayout chartContainer = (LinearLayout) findViewById(R.id.chart_container);

            // Creating a Line Chart
            mChart = ChartFactory.getLineChartView(getBaseContext(), dataset, multiRenderer);

            // Adding the Line Chart to the LinearLayout
            chartContainer.addView(mChart);


        }

        @Override
        public boolean onCreateOptionsMenu(Menu menu) {

            // Inflate the menu; this adds items to the action bar if it is present.
            getMenuInflater().inflate(R.menu.main, menu);
            return true;
        }

        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            // Handle action bar item clicks here. The action bar will
            // automatically handle clicks on the Home/Up button, so long
            // as you specify a parent activity in AndroidManifest.xml.
            int id = item.getItemId();
            if (id == R.id.action_settings) {
                return true;
            }
            return super.onOptionsItemSelected(item);
        }

        /**
         * A placeholder fragment containing a simple view.
         */
        public static class PlaceholderFragment extends Fragment {

            public PlaceholderFragment() {
            }

            @Override
            public View onCreateView(LayoutInflater inflater, ViewGroup container,
                    Bundle savedInstanceState) {
                View rootView = inflater.inflate(R.layout.activity_main, container,
                        false);
                return rootView;
            }
        }

    }

activity_main.xml

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.linecharts.MainActivity$PlaceholderFragment">

    <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"
        android:orientation="horizontal" >
    </LinearLayout>


</RelativeLayout>

list 文件.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.linecharts"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="19" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.linecharts.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

LogCat 文件

06-16 00:31:12.640: E/AndroidRuntime(1282): FATAL EXCEPTION: main
06-16 00:31:12.640: E/AndroidRuntime(1282): Process: com.example.linecharts, PID: 1282
06-16 00:31:12.640: E/AndroidRuntime(1282): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.linecharts/com.example.linecharts.MainActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.os.Handler.dispatchMessage(Handler.java:102)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.os.Looper.loop(Looper.java:136)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.app.ActivityThread.main(ActivityThread.java:5017)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at java.lang.reflect.Method.invokeNative(Native Method)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at java.lang.reflect.Method.invoke(Method.java:515)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at dalvik.system.NativeStart.main(Native Method)
06-16 00:31:12.640: E/AndroidRuntime(1282): Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.support.v7.app.ActionBarActivityDelegate.onCreate(ActionBarActivityDelegate.java:111)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.support.v7.app.ActionBarActivityDelegateICS.onCreate(ActionBarActivityDelegateICS.java:58)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:98)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at com.example.linecharts.MainActivity.onCreate(MainActivity.java:32)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.app.Activity.performCreate(Activity.java:5231)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
06-16 00:31:12.640: E/AndroidRuntime(1282):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
06-16 00:31:12.640: E/AndroidRuntime(1282):     ... 11 more

Answer 1

正如您的 Logcat 显示的那样，您正在使用支持库中的 Actionbar。因此，在您的 AndroidManifest.xml 中，在应用程序标记中使用 android:theme="@style/Theme.AppCompat"。