Java 将图表放在android弹出窗口上

我正在使用AChartEngine制作图表，到目前为止，它似乎运行得很好。 唯一能让这个完美的就是能够把这个图表放在一个弹出窗口上。不幸的是，我不知道怎么做。每当我尝试在弹出窗口中包含要调用的图表函数时，我都会得到一个NullPointerException。这是我的弹出窗口的代码（每当我点击一个按钮时就会调用）

以下是相关的弹出式布局xml代码：

      <TextView
         android:id="@+id/textView1"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="Popup"
         android:textAppearance="?android:attr/textAppearanceLarge" />

      <TextView
         android:id="@+id/textView2"
         android:layout_marginTop="5dp"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="This is a simple popup" />

         <Button
         android:id="@+id/dismiss"
         android:layout_marginTop="10dp"
         android:layout_gravity="center_horizontal"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="Close" />


         <LinearLayout
              android:orientation="horizontal"
              android:id="@+id/chart_container"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:layout_below="@id/tv_title" >

          </LinearLayout>

---

哪一行给了您空指针异常？当我将图表添加到视图时会发生这种情况。我没有包括图表代码，因为它很长，但基本上是：chartContainer.addView（mChart）；（如果不尝试将其放在弹出窗口中，这将非常有效）那么您基本上要问的是，为什么

chartContainer

不应该为空。如果不看你的密码，我无法回答这个问题。但我可以建议您使用调试器进行调试；只是为了验证

chartContainer

实际上是空的，并找出为什么将其设置为非空的代码没有运行。我刚刚添加了一个较短版本的图表代码。您确定它发生在

chartContainer.addView（mChart）上吗？在堆栈跟踪中没有任何高于此的内容？
      <TextView
         android:id="@+id/textView1"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="Popup"
         android:textAppearance="?android:attr/textAppearanceLarge" />

      <TextView
         android:id="@+id/textView2"
         android:layout_marginTop="5dp"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="This is a simple popup" />

         <Button
         android:id="@+id/dismiss"
         android:layout_marginTop="10dp"
         android:layout_gravity="center_horizontal"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="Close" />


         <LinearLayout
              android:orientation="horizontal"
              android:id="@+id/chart_container"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:layout_below="@id/tv_title" >

          </LinearLayout>

 private void openChart(){

        Date[] dt = new Date[dates.size()];
        float[] visits = new float[dates.size()];
        for(int i=0;i<dates.size();i++){
            try {
                dt[i]= new SimpleDateFormat("yyyy-MM-dd").parse(dates.get(i));
                visits[i] = Float.parseFloat(distance.get(i));
            } catch (ParseException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        TimeSeries visitsSeries = new TimeSeries("Visits");

        for(int i=0;i<dt.length;i++){
            visitsSeries.add(dt[i], visits[i]);
        }

        XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();

        dataset.addSeries(visitsSeries);

        XYSeriesRenderer visitsRenderer = new XYSeriesRenderer();
        visitsRenderer.setColor(Color.BLACK);
        visitsRenderer.setPointStyle(PointStyle.CIRCLE);
        visitsRenderer.setFillPoints(true);
        visitsRenderer.setLineWidth(2);
        visitsRenderer.setDisplayChartValues(true);

        XYMultipleSeriesRenderer multiRenderer = new XYMultipleSeriesRenderer();

        multiRenderer.addSeriesRenderer(visitsRenderer);

        LinearLayout chartContainer = (LinearLayout) findViewById(R.id.chart_container);

        mChart = (GraphicalView) ChartFactory.getTimeChartView(getBaseContext(), dataset, multiRenderer,"dd-MMM-yyyy");

        multiRenderer.setClickEnabled(true);
        multiRenderer.setSelectableBuffer(10);

            chartContainer.addView(mChart);
    }

 05-16 10:45:39.013: E/AndroidRuntime(6311): FATAL EXCEPTION: main
 05-16 10:45:39.013: E/AndroidRuntime(6311): Process: com.example.jfitnessfunctiontester, PID: 6311
 05-16 10:45:39.013: E/AndroidRuntime(6311): java.lang.NullPointerException
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at activities.ReportListViewActivity.openChart(ReportListViewActivity.java:256)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at activities.ReportListViewActivity.popupWindow(ReportListViewActivity.java:115)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at activities.ReportListViewActivity$2.onClick(ReportListViewActivity.java:137)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at android.view.View.performClick(View.java:4438)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at android.view.View$PerformClick.run(View.java:18422)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at android.os.Handler.handleCallback(Handler.java:733)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at android.os.Handler.dispatchMessage(Handler.java:95)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at android.os.Looper.loop(Looper.java:136)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at android.app.ActivityThread.main(ActivityThread.java:5017)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at java.lang.reflect.Method.invokeNative(Native Method)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at java.lang.reflect.Method.invoke(Method.java:515)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
 05-16 10:45:39.013: E/AndroidRuntime(6311):    at dalvik.system.NativeStart.main(Native Method)