Android 片段UI组件空文本视图

这里是新的android开发者。我正在尝试创建一个动态UI，该UI根据用户对RadioGroup的选择进行加载。根据他们的选择，3个可能片段中的一个将加载到LinearLayout部分。这是我第一次尝试自己的示例问题，它不仅仅是一个穿行教程。以下是主要活动：

public class BaseConverter extends Activity {
    RadioGroup convert;
    Fragment toFragment;

    RadioGroup toRadioGroup = null;
    TextView inputDisplay = null;
    TextView outputDisplay = null;
    TextView resultTitle = null;    

    @Override
    public void onCreate(Bundle sIS) {
        super.onCreate(sIS);
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        this.setContentView(R.layout.base_converter);
        convert = (RadioGroup) this.findViewById(R.id.bc_convert_group);
        convert.setOnCheckedChangeListener(new ConvertListener());

        FragmentManager fm = getFragmentManager();

        FragmentTransaction converterFragment = fm.beginTransaction();
        ConvertEmptyFragment emptyTo = new ConvertEmptyFragment();
        converterFragment.replace(R.id.bc_converter_fragment, emptyTo);
        converterFragment.commit();

        FragmentTransaction toFragment = fm.beginTransaction();
        ConvertEmptyFragment emptyConverter = new ConvertEmptyFragment();
        toFragment.replace(R.id.bc_to_fragment, emptyConverter);
        toFragment.commit();
    }

    @Override
    public void onResume() {
        convert.clearCheck();
        super.onResume();
    }

    @Override
    public void onPause() {
        convert.clearCheck();
        super.onPause();
    }

    // I put a little null check so you can see how I'm trying to access the TextViews and what results
    public void updateUIComponents(){
        View converterView = this.findViewById(R.id.bc_converter_fragment);
        inputDisplay = (TextView)converterView.findViewById(R.id.bc_display_input);
        outputDisplay = (TextView)converterView.findViewById(R.id.bc_display_output);
        if (inputDisplay == null){
            Log.d("BaseConverter", "inputDisplay == null");
        } else {
            Log.d("BaseConverter", "inputDisplay != null");
        }
    }

    class ConvertListener implements OnCheckedChangeListener {
        @Override
        public void onCheckedChanged(RadioGroup group, int checkedId) {
            Fragment toFragment;
            Fragment converterFragment;
            switch (checkedId) {
            case R.id.bc_convert_binary:
                toFragment = new ConvertRBFragmentBinary();
                converterFragment = new ConverterFragmentBinary();
                break;
            case R.id.bc_convert_decimal:
                toFragment = new ConvertRBFragmentDecimal();
                converterFragment = new ConverterFragmentDecimal();
                break;
            case R.id.bc_convert_hex:
                toFragment = new ConvertRBFragmentHex();
                converterFragment = new ConverterFragmentHex();
                break;
            default:
                toFragment = new ConvertEmptyFragment();
                converterFragment = new ConvertEmptyFragment();
                break;
            }
            FragmentManager fm = getFragmentManager();

            FragmentTransaction converterTransaction = fm.beginTransaction();
            converterTransaction.replace(R.id.bc_converter_fragment, converterFragment);
            converterTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
            converterTransaction.commit();

            FragmentTransaction toTransaction = fm.beginTransaction();
            toTransaction.replace(R.id.bc_to_fragment, toFragment);
            toTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
            toTransaction.commit();

            updateUIComponents();
        }
    }

因此，根据用户的选择，适当的片段将加载到相应的LinearLayout部分。然而，现在我想实现片段的业务逻辑（这只是整数基转换；即二进制数到十进制数…），但是当我尝试访问TextView时，如updateUIComponents方法中所示，我得到了空指针。我错过了什么

以下是ConverterFragmentBinary类供参考：

public class ConverterFragmentBinary extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle sIS){
        View v = inflater.inflate(R.layout.converter_fragment_binary, container, false);
        return v;
    }   
}    

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FF000000"
    android:gravity="center_horizontal"
    android:orientation="vertical" >

    <ImageView
        android:id="@+id/bc_binary_converter_logo"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="15dip"
        android:maxHeight="30dip"
        android:src="@drawable/binary_converter" />

    <TextView
        android:id="@+id/bc_display_input"
        style="@style/input_text"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="5dip"
        android:layout_marginLeft="15dip"
        android:layout_marginRight="15dip"
        android:layout_marginTop="5dip"
        android:gravity="center_vertical|right"
        android:lines="1"
        android:minHeight="30sp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#FF000000"
        android:gravity="center_horizontal"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/button_num_0"
            style="@style/op_button_land"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dip"
            android:gravity="center"
            android:onClick="num0"
            android:text="@string/num_0" />

        <Button
            android:id="@+id/button_num_1"
            style="@style/op_button_land"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dip"
            android:gravity="center"
            android:onClick="num1"
            android:text="@string/num_1" />
    </LinearLayout>

    <TextView
        android:id="@+id/bc_result_title"
        style="@style/radio_button_header"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="5dip"
        android:layout_marginRight="5dip"
        android:layout_marginTop="10dip"
        android:gravity="left"
        android:text="@string/choose_convert" />

    <TextView
        android:id="@+id/bc_display_output"
        style="@style/display_text"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="15dip"
        android:layout_marginRight="15dip"
        android:layout_marginTop="5dip"
        android:gravity="center_vertical|right"
        android:lines="1"
        android:minHeight="30sp" />
</LinearLayout>

及其各自的xml布局，以供参考：

public class ConverterFragmentBinary extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle sIS){
        View v = inflater.inflate(R.layout.converter_fragment_binary, container, false);
        return v;
    }   
}    

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FF000000"
    android:gravity="center_horizontal"
    android:orientation="vertical" >

    <ImageView
        android:id="@+id/bc_binary_converter_logo"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="15dip"
        android:maxHeight="30dip"
        android:src="@drawable/binary_converter" />

    <TextView
        android:id="@+id/bc_display_input"
        style="@style/input_text"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="5dip"
        android:layout_marginLeft="15dip"
        android:layout_marginRight="15dip"
        android:layout_marginTop="5dip"
        android:gravity="center_vertical|right"
        android:lines="1"
        android:minHeight="30sp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#FF000000"
        android:gravity="center_horizontal"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/button_num_0"
            style="@style/op_button_land"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dip"
            android:gravity="center"
            android:onClick="num0"
            android:text="@string/num_0" />

        <Button
            android:id="@+id/button_num_1"
            style="@style/op_button_land"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dip"
            android:gravity="center"
            android:onClick="num1"
            android:text="@string/num_1" />
    </LinearLayout>

    <TextView
        android:id="@+id/bc_result_title"
        style="@style/radio_button_header"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="5dip"
        android:layout_marginRight="5dip"
        android:layout_marginTop="10dip"
        android:gravity="left"
        android:text="@string/choose_convert" />

    <TextView
        android:id="@+id/bc_display_output"
        style="@style/display_text"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="15dip"
        android:layout_marginRight="15dip"
        android:layout_marginTop="5dip"
        android:gravity="center_vertical|right"
        android:lines="1"
        android:minHeight="30sp" />
</LinearLayout>

下面是它加载到的主要活动：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/base_conversion_layout"
    style="@style/layout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_gravity="center_horizontal"
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="0dip"
        android:layout_weight="5"
        android:baselineAligned="false"
        android:gravity="center_vertical|left"
        android:orientation="horizontal" >

        <LinearLayout
            android:layout_width="0dip"
            android:layout_height="match_parent"
            android:layout_weight="2"
            android:orientation="vertical" >

            <TextView
                style="@style/radio_button_header"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/convert" />

            <RadioGroup
                android:id="@+id/bc_convert_group"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center_horizontal"
                android:padding="5dip" >

                <RadioButton
                    android:id="@+id/bc_convert_binary"
                    style="@style/radio_button"
                    android:text="@string/binary" />

                <RadioButton
                    android:id="@+id/bc_convert_decimal"
                    style="@style/radio_button"
                    android:text="@string/decimal" />

               <RadioButton
                    android:id="@+id/bc_convert_hex"
                    style="@style/radio_button"
                    android:text="@string/hex" />
            </RadioGroup>
        </LinearLayout>

        <LinearLayout
            android:id="@+id/bc_to_fragment"
            android:layout_width="0dip"
            android:layout_height="match_parent"
            android:layout_weight="3"
            android:orientation="vertical" >
        </LinearLayout>
    </LinearLayout>
    <LinearLayout
        android:id="@+id/bc_converter_fragment"
        android:layout_width="fill_parent"
        android:layout_height="0dip"
        android:layout_weight="13"
        android:orientation="vertical" >
    </LinearLayout>

</LinearLayout>

---

提前感谢您，很抱歉代码块太长，但我认为最好包含更多而不是更少。

此外，您应该扩大片段布局，将其从XML带到Java代码中，而不是简单地使用findviewbyd（）方法引用它

因此，与其这样做

View converterView = this.findViewById(R.id.bc_converter_fragment);

在片段的onCreateView方法中执行此操作

View converterView = infalter.inflate(R.id.bc_converter_fragment,null);
updateUIComponents(converterView);//call this methid and pass your view

新方法是这样的,

public void updateUIComponents(View converterView){

    inputDisplay = (TextView)converterView.findViewById(R.id.bc_display_input);
    outputDisplay = (TextView)converterView.findViewById(R.id.bc_display_output);
    if (inputDisplay == null){
        Log.d("BaseConverter", "inputDisplay == null");
    } else {
        Log.d("BaseConverter", "inputDisplay != null");
    }
}

---

这些文本视图属于片段而不是活动该片段是否应该是活动的内部类才能工作？如果它们是静态的，则可以工作，内部类以及文本视图和updateUIComponents方法也是静态的。