java - 无法解析 Fragment 中的 setText(java.lang.String) 方法

Question

我正在使用计步器来计算自上次重新启动设备以来的步数。

我创建了一个 TextView ，我想将其文本设置为使用传感器时的步数。 (我的TextView叫做count)

我执行此操作的代码是:

@Override
public void onSensorChanged(SensorEvent event) {
    if (activityRunning) {
        count.setText(String.valueOf(event.values[0]));
    }

我在这里收到错误无法解析方法setText(java.lang.String)

如果有助于解决问题，我可以发布类(class)的其余部分

谢谢

这是类(class)的其余部分:

public class Tab3 extends Fragment implements SensorEventListener {

private SensorManager sensorManager;
private TextView textView;
boolean activityRunning;
private Button buttonReturn;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.tab3, container, false);

    TextView count = (TextView) getActivity().findViewById(R.id.count);

    sensorManager = (SensorManager) getActivity().getSystemService(Context.SENSOR_SERVICE);

    getActivity().getSystemService(Context.SENSOR_SERVICE);

    return rootView;
}

@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
}

@Override
public void onResume() {
    super.onResume();
    activityRunning = true;
    Sensor countSensor = sensorManager.getDefaultSensor(Sensor.TYPE_STEP_COUNTER);
    if (countSensor != null) {
        sensorManager.registerListener(this, countSensor, SensorManager.SENSOR_DELAY_UI);
    } else {
        Toast.makeText(getActivity(), "Count sensor not available!", Toast.LENGTH_LONG).show();
    }

}

@Override
public void onPause() {
    super.onPause();
    activityRunning = false;
}

@Override
public void onSensorChanged(SensorEvent event) {
    if (activityRunning) {
        count.setText(String.valueOf(event.values[0]));
    }

}

@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {

}
}

这是与此类关联的 XML 文件:

<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.application.placepicker.TabbedActivity$PlaceholderFragment">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:layout_marginTop="114dp"
    android:gravity="center"
    android:layout_alignParentTop="true"
    android:layout_alignParentStart="true">

    <TextView
        android:id="@+id/textLogin"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:text="Step counter"
        android:textSize="40sp"
        android:textColor="@color/colorAccent"
        android:fontFamily="sans-serif"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="33dp"
        android:layout_gravity="center_horizontal"
        android:textSize="26dp"
        android:text="Steps walked so far today:"
        android:textColor="@color/colorAccent" />

    <TextView
        android:id="@+id/count"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="40dp"
        android:layout_marginLeft="50dp"
        android:text="---"
        android:textColor="@color/colorAccent"
        android:textSize="36dp" />

</LinearLayout>

Answer 1

改变

private TextView textView;

到

private TextView count;

并改变

TextView count = (TextView) getActivity().findViewById(R.id.count);

至

count = (TextView) getActivity().findViewById(R.id.count);