调用SetText()时,片段布局中的Textview不会更改

Question

我的应用程序(最低级别13)是一个Activity,它使用操作栏中的选项卡来管理一些与此非常相似的片段.

现在,活动启动一个服务,它执行连续计算并返回我想在片段中显示的值.活动 - 服务通信通过广播接收器实现,并且活动将数据移动到适当的片段.

一切似乎都设置正确,数据使其成为Fragment更新方法,但是当我尝试在textviews中显示新值时,永远不会显示新值.

更改文本视图的代码:

    TextView tv = (TextView) getView().findViewById(R.id.fieldNavGpsTime);
    Double doub = input.getDoubleExtra("com.some.thing.GPS_TIME", -1.0);
    tv.setText(doub.toString());

从Activity中的广播接收器调用Fragments更新方法的代码:

    NavigationGuiFragment navfrag = (NavigationGuiFragment) getFragmentManager().findFragmentByTag("navigation");
    if (navfrag != null && navfrag.isResumed())
        navfrag.UpdateNavUI(intent);

我注意到isVisible()似乎永远不会返回true,但我不确定它是什么意思或如何改变它.

此外,我似乎无法以编程方式将图像视图添加到Fragment.这是代码(驻留在onActivityCreated()中):

    this.compass = new BasicCompass(getActivity());
    LinearLayout ll = (LinearLayout) getView().findViewById(R.id.nav_hrztl_lnly);
    ll.addView(this.compass);

BasicCompass构造函数接受Context,当然我并不完全确定我传入的内容是否正确.

这个代码或多或少取自工作的Activity,并放入Fragment以允许选项卡.我很乐意就改变代码结构提出建议.

谢谢你的帮助.

编辑

片段的xml布局:

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/nav_hrztl_lnly"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
android:focusable="true"
android:focusableInTouchMode="true"
android:baselineAligned="false" >

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="600dp"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:focusable="true"
    android:focusableInTouchMode="true" >

    <EditText
        android:id="@+id/labelNavGpsTime"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/gps_time" />

    <EditText
        android:id="@+id/fieldNavGpsTime"
        style="@style/field_padding"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="@string/zero_3_digits"
        android:inputType="numberDecimal" />

    <EditText
        android:id="@+id/labelNavLatitude"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/latitude" />

    <EditText
        android:id="@+id/fieldNavLatitude"
        style="@style/field_padding"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="@string/zero_6_digits"
        android:inputType="numberDecimal" />

    <EditText
        android:id="@+id/labelNavLongitude"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/longitude" />

    <EditText
        android:id="@+id/fieldNavLongitude"
        style="@style/field_padding"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="@string/zero_6_digits"
        android:inputType="numberDecimal" />

    <EditText
        android:id="@+id/labelNavAltitude"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/altitude" />

    <EditText
        android:id="@+id/fieldNavAltitude"
        style="@style/field_padding"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="@string/zero_3_digits"
        android:inputType="numberDecimal" />

    <EditText
        android:id="@+id/labelNavRoll"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/roll" />

    <EditText
        android:id="@+id/fieldNavRoll"
        style="@style/field_padding"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="@string/zero_6_digits"
        android:inputType="numberDecimal" />

    <EditText
        android:id="@+id/labelNavPitch"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/pitch" />

    <EditText
        android:id="@+id/fieldNavPitch"
        style="@style/field_padding"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="@string/zero_6_digits"
        android:inputType="numberDecimal" />

    <EditText
        android:id="@+id/labelNavAzimuth"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/azimuth_heading" />

    <EditText
        android:id="@+id/fieldNavAzimuth"
        style="@style/field_padding"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="@string/zero_6_digits"
        android:inputType="numberDecimal" />

    <LinearLayout
        android:id="@+id/nav_rdbtn_lnly"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <RadioButton
            android:id="@+id/rdbtnNavGpsAvailability"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/gps_avail" />

        <RadioButton
            android:id="@+id/rdbtnNavZuptStatus"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/zupt_stat" />

    </LinearLayout>

</LinearLayout>

而使用它的片段:

public class NavigationGuiFragment extends Fragment
{
private RadioButton gpsRdBtn;
private RadioButton zuptRdBtn;
private BasicCompass compass;

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

    // sets up the rose image that serves as a compass in the GUI
    this.compass = new BasicCompass(getActivity());
    LinearLayout ll = (LinearLayout) fragview.findViewById(R.id.nav_hrztl_lnly);
    ll.addView(this.compass);

    return fragview;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) 
{
    super.onActivityCreated(savedInstanceState);
    getActivity().setContentView(R.layout.navigation_fragment);

    //Initialize the radio buttons
    gpsRdBtn = (RadioButton) getView().findViewById(R.id.rdbtnNavGpsAvailability);
    gpsRdBtn.setChecked(false);

    zuptRdBtn = (RadioButton) getView().findViewById(R.id.rdbtnNavZuptStatus);
    zuptRdBtn.setChecked(false);    
}

@Override
public void onResume() 
{
    super.onResume();

    if (!IsMyServiceRunning())
    {
        gpsRdBtn.setChecked(false);
        zuptRdBtn.setChecked(false);
    }
}

public void UpdateNavUI(Intent input)
{       
    TextView tv = (TextView) getView().findViewById(R.id.fieldNavGpsTime);
    Double doub = input.getDoubleExtra("com.some.thing.GPS_TIME", -1.0);
    tv.setText(doub.toString());

    tv = (TextView) getView().findViewById(R.id.fieldNavLatitude);
    doub = input.getDoubleExtra("com.some.thing.LATITUDE", 100000.0);
    tv.setText(doub.toString());

    tv = (TextView) getView().findViewById(R.id.fieldNavLongitude);
    doub = input.getDoubleExtra("com.some.thing.LONGITUDE", 100000.0);
    tv.setText(doub.toString());

    tv = (TextView) getView().findViewById(R.id.fieldNavAltitude);
    doub = input.getDoubleExtra("com.some.thing.ALTITUDE", -1.0);
    tv.setText(doub.toString());

    tv = (TextView) getView().findViewById(R.id.fieldNavRoll);
    doub = input.getDoubleExtra("com.some.androidndk.ROLL", 361.0);
    tv.setText(doub.toString());

    tv = (TextView) getView().findViewById(R.id.fieldNavPitch);
    doub = input.getDoubleExtra("com.some.thing.PITCH", 361.0);
    tv.setText(doub.toString());

    tv = (TextView) getView().findViewById(R.id.fieldNavAzimuth);
    doub = input.getDoubleExtra("com.some.thing.AZIMUTH", 361.0);
    tv.setText(doub.toString());

    this.compass.SetDirection(doub.floatValue());

    boolean bool = input.getBooleanExtra("com.some.thing.ZUPT_STATUS", false);
    zuptRdBtn.setChecked(bool);

    UpdateGpsIndicator(input);
}

public void UpdateGpsIndicator(Intent input)
{
    boolean bool = input.getBooleanExtra("com.some.thing.GPS_ON", false);
    gpsRdBtn.setChecked(bool);
}

private boolean IsMyServiceRunning()
{
    ActivityManager manager = (ActivityManager) getActivity().getSystemService(Context.ACTIVITY_SERVICE);
    for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE))
    {
        if ("com.some.thing.Service".equals(service.service.getClassName())) 
            return true;
    }

    return false;
}

}

Answer 1

这一行:

getActivity().setContentView(R.layout.navigation_fragment);

应该调用Activity.onCreate() 并确保它只被调用一次.在你的代码中,每次Fragment进入活动状态时都会调用它.而TextView和RaidoButton其他相关信息将被重置为在陈述布局XML定义.

Checkout片段生命周期在这里.

更新: 某些视图小部件的状态将由Activity保存,例如TextView.尝试将您的setXXX()方法移动到onResume().我的经验setXXX()不起作用,onActivityCreated()但效果很好onResume().