Question

我想在弹出窗口中显示饼图。我正在使用＆＃34; achartengine-1.0.0＆＃34; 这是我的代码： -

AndroidPopupWindowActivity111.java

   @SuppressLint("InflateParams")
public class AndroidPopupWindowActivity111 extends Activity {

    private static int[] COLORS = new int[] { Color.MAGENTA, Color.CYAN };  
    LinearLayout layout;
    private static String[] NAME_LIST = new String[] { "A", "B" };  
    private CategorySeries mSeries = new CategorySeries("");  
    private DefaultRenderer mRenderer = new DefaultRenderer();  
    private GraphicalView mChartView;  



    private  int[] VALUES = { 40, 60};


    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.popup_main);

        mRenderer.setApplyBackgroundColor(true);
        mRenderer.setBackgroundColor(Color.argb(100, 50, 50, 50));  
        mRenderer.setChartTitleTextSize(20);  
        mRenderer.setLabelsTextSize(15);  
        mRenderer.setLegendTextSize(15);  
        mRenderer.setMargins(new int[] { 20, 30, 15, 0 });  
        mRenderer.setZoomButtonsVisible(true);  
        mRenderer.setStartAngle(90);  

        for (int i = 0; i < VALUES.length; i++) {  
        //mSeries.add(NAME_LIST[i] + " " + VALUES[i], VALUES[i]);  
            mSeries.add(NAME_LIST[i] + "(" + VALUES[i]+"%)", VALUES[i]);  
            SimpleSeriesRenderer renderer = new SimpleSeriesRenderer();  
        renderer.setColor(COLORS[(mSeries.getItemCount() - 1) % COLORS.length]);  
        mRenderer.addSeriesRenderer(renderer);  
        }  

        if (mChartView != null) {  
        mChartView.repaint();  
        }  

        final Button btnOpenPopup = (Button)findViewById(R.id.openpopup);
        btnOpenPopup.setOnClickListener(new Button.OnClickListener(){

   @Override
   public void onClick(View arg0) {
    LayoutInflater layoutInflater 
     = (LayoutInflater)getBaseContext()
      .getSystemService(LAYOUT_INFLATER_SERVICE);  
    View popupView = layoutInflater.inflate(R.layout.main_piechart, null);  
             final PopupWindow popupWindow = new PopupWindow( popupView, LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);  
             layout = (LinearLayout) findViewById(R.id.chart);  
             Button btnDismiss = (Button)popupView.findViewById(R.id.dismiss);
             btnDismiss.setOnClickListener(new Button.OnClickListener(){

     @Override
     public void onClick(View v) {
      // TODO Auto-generated method stub
      popupWindow.dismiss();
     }});

             popupWindow.showAsDropDown(btnOpenPopup, 50, -30);

   }});
    }

    @SuppressLint("ShowToast")
    @Override  
    protected void onResume() {  
    super.onResume();  
    if (mChartView == null) {  

    mChartView = ChartFactory.getPieChartView(this, mSeries, mRenderer);  
    mRenderer.setClickEnabled(true);  
    mRenderer.setSelectableBuffer(10);  

    mChartView.setOnClickListener(new View.OnClickListener() {  
    @Override  
    public void onClick(View v) {  
    SeriesSelection seriesSelection = mChartView.getCurrentSeriesAndPoint();  

    if (seriesSelection == null) {  
    Toast.makeText(AndroidPopupWindowActivity111.this,"No chart element was clicked",Toast.LENGTH_SHORT).show();  
    } else {  
    Toast.makeText(AndroidPopupWindowActivity111.this,"Chart element data point index "+ (seriesSelection.getPointIndex()+1) + " was clicked" + " point value="+ seriesSelection.getValue(), Toast.LENGTH_SHORT).show();  
    }  
    }  
    });  

    mChartView.setOnLongClickListener(new View.OnLongClickListener() {  
    @SuppressLint("ShowToast")
    @Override  
    public boolean onLongClick(View v) {  
    SeriesSelection seriesSelection = mChartView.getCurrentSeriesAndPoint();  
    if (seriesSelection == null) {  
    Toast.makeText(AndroidPopupWindowActivity111.this,"No chart element was long pressed", Toast.LENGTH_SHORT);  
    return false;   
    } else {  
    Toast.makeText(AndroidPopupWindowActivity111.this,"Chart element data point index "+ seriesSelection.getPointIndex()+ " was long pressed",Toast.LENGTH_SHORT);  
    return true;         
    }  
    }  
    });  
    layout.addView(mChartView, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));  
    }  
    else {  
    mChartView.repaint();  
    }  
    }  
}

popup_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="hellooo" />
    <Button
        android:id="@+id/openpopup"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Open Popup Window" />

</LinearLayout>

main_piechart.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    android:layout_width="fill_parent"  
    android:layout_height="fill_parent"  
    android:orientation="vertical" 
    android:paddingLeft="10dp"
    android:paddingRight="10dp"  
    android:paddingTop="30dp">

    <LinearLayout
        android:id="@+id/chart"
        android:layout_width="300dp"
        android:layout_height="190dp"

        android:orientation="horizontal" >

    </LinearLayout>  

     <Button
      android:id="@+id/dismiss"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:text="Dismiss" />

</LinearLayout>

当我运行此程序时..它显示错误：---

Process: in.wptrafficanalyzer.achartenginepiechart, PID: 14513
 java.lang.RuntimeException: Unable to resume activity {in.wptrafficanalyzer.achartenginepiechart/in.wptrafficanalyzer.achartenginepiechart.AndroidPopupWindowActivity111}: java.lang.NullPointerException
    at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2972)
    at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3001)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2403)
    at android.app.ActivityThread.access$800(ActivityThread.java:159)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1329)
    at android.os.Handler.dispatchMessage(Handler.java:110)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:5324)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
    at dalvik.system.NativeStart.main(Native Method)
 Caused by: java.lang.NullPointerException
    at in.wptrafficanalyzer.achartenginepiechart.AndroidPopupWindowActivity111.onResume(AndroidPopupWindowActivity111.java:130)
    at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1197)

该程序的错误在哪里？我不能理解......提前谢谢

Answer 1

下面：

layout.addView（mChartView，new LayoutParams（LayoutParams.MATCH_PARENT，LayoutParams.MATCH_PARENT））;

导致问题的行，因为layout未初始化。您正在按钮点击初始化layout，但在活动开始时调用onResume。

在layout之后onCreate初始化setContentView：<{1}}：

layout = (LinearLayout) findViewById(R.id.chart);

如何在弹出窗口中显示Android饼图？

1 个答案: