Question

您好，并提前感谢您的帮助，

我正在尝试使用ArrayList currentBodyTemp中的信息在此窗口中显示线图，但是当我切换到bodyTempInfo视图时，我收到错误？

出了什么问题？

bodyTempInfo类

public class bodyTempInfo extends AppCompatActivity {


    ArrayList<Double> currentBodyTemp;

    private int[] arraySize;
    private double[] arrayInformation;


    private void fillGraph() {

        int i = 0;
        for(i = 0; i < currentBodyTemp.size(); i++) {
            arraySize[i] = i;
            arrayInformation[i] = currentBodyTemp.get(i);
        }

    }


    private void displayBodyTemp(String bodyTemp) {
        TextView textView = (TextView) findViewById(R.id.bodyTempInfoArray);
        textView.setText(bodyTemp);
    }

    public void displayCurrentBodyTempArray(View view) throws FileNotFoundException {

        ArrayList<Double> list = new ArrayList<>();

        File sdcard = Environment.getExternalStorageDirectory();

//Get the text file


//Read text from file

        File file = new File(sdcard, "Download/temp.txt");

        StringBuilder text = new StringBuilder();

        try {

            BufferedReader br = new BufferedReader(new FileReader(file));
            String line;

            while ((line = br.readLine()) != null) {
                text.append(line);
                list.add(Double.parseDouble(line));
                text.append('\n');
            }
            br.close();
        }
        catch(IOException e) {
            throw new Error(e);
        }

        currentBodyTemp = list;
        displayBodyTemp("Your Body Temperature Readings are: " + text);

    }


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_body_temp_info);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);



        try {
            displayCurrentBodyTempArray(findViewById(R.id.bodyTempInfoArray));
        } catch (FileNotFoundException e) {
            throw new Error(e);
        }

        LineChart chart = (LineChart) findViewById(R.id.chart);

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        fillGraph();
        chart.setDragEnabled(true);
        chart.setScaleEnabled(true);
        chart.setDrawGridBackground(false);
        chart.setPinchZoom(true);



        int i = 0;

        ArrayList<Entry> vals = new ArrayList<Entry>();

        for (i=0; i<currentBodyTemp.size(); i++) {


            Entry entry = new Entry(currentBodyTemp.get(i).floatValue(), i);
            vals.add(entry);

        }


        LineDataSet set = new LineDataSet(vals, "Body Temperature");
        set.setAxisDependency(YAxis.AxisDependency.LEFT);

        ArrayList<LineDataSet> dataSet = new ArrayList<LineDataSet>();
        ArrayList<String> xVals = new ArrayList<String>();
        dataSet.add(set);

        for (i=0; i<currentBodyTemp.size(); i++) {
            xVals.add(String.valueOf(i));
        }

        LineData data = new LineData(xVals, dataSet);
        chart.setData(data);
        chart.invalidate();





    }





}

content_body_temp_info.xml

 <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

    <com.github.mikephil.charting.charts.BarChart
        android:id="@+id/chart"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight = "1"
        android:layout_margin = "8dp"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text = "Body Temperature Measurements will go here"
        android:id = "@+id/bodyTempInfoArray"
        android:layout_weight = "0"/>



    <com.github.mikephil.charting.charts.BarChart
        android:id="@+id/chart2"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight = "1"
        android:layout_margin = "8dp"/>

    </LinearLayout>

错误消息

10-26 13:36:28.535 11615-11615/com.teamfara.circadianrhythmmonitor4 D/AndroidRuntime: Shutting down VM
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime: FATAL EXCEPTION: main
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime: Process: com.teamfara.circadianrhythmmonitor4, PID: 11615
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.teamfara.circadianrhythmmonitor4/com.teamfara.circadianrhythmmonitor4.bodyTempInfo}: java.lang.ClassCastException: com.github.mikephil.charting.charts.BarChart cannot be cast to com.github.mikephil.charting.charts.LineChart
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3119)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3218)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.ActivityThread.access$1000(ActivityThread.java:198)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1676)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:102)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:145)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:6837)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:  Caused by: java.lang.ClassCastException: com.github.mikephil.charting.charts.BarChart cannot be cast to com.github.mikephil.charting.charts.LineChart
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at com.teamfara.circadianrhythmmonitor4.bodyTempInfo.onCreate(bodyTempInfo.java:102)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.Activity.performCreate(Activity.java:6500)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1120)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3072)
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3218) 
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.ActivityThread.access$1000(ActivityThread.java:198) 
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1676) 
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:102) 
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:145) 
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:6837) 
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method) 
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372) 
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404) 
10-26 13:36:28.545 11615-11615/com.teamfara.circadianrhythmmonitor4 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)

Answer 1

异常本身有一个解决方案：

Caused by: java.lang.ClassCastException: com.github.mikephil.charting.charts.BarChart cannot be cast to com.github.mikephil.charting.charts.LineChart.

您正在尝试将Barchart转换为LineChart。看看您的布局和活动代码。

在你的布局中：

<com.github.mikephil.charting.charts.BarChart
        android:id="@+id/chart"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight = "1"
        android:layout_margin = "8dp"/>

在你的活动中，你试图将BarChart转换为LineChart。

LineChart chart = (LineChart) findViewById(R.id.chart);

替换您的观点或更新您的活动代码。

使用MPAndroid Chart创建LineChart错误，无法启动活动

1 个答案: