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问如何在公共类ItemThreeFragment扩展片段中使用findViewById
EN

Stack Overflow用户

提问于 2017-12-07 12:58:06

回答 2查看 140关注 0票数 0

我想在我的片段中显示另一个片段，当我运行它时，它会显示一个错误：(31，75) error:找不到符号方法findViewById(int)，它们是某种我可以在片段类中使用findViewByID而不是AppCompatActivity的方式吗？

ItemThreeFragment.java

public class ItemThreeFragment extends Fragment {


private BottomNavigationView bottomNavigationView;

public static ItemThreeFragment newInstance() {
    ItemThreeFragment fragment = new ItemThreeFragment();
    return fragment;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    BottomNavigationView bottomNavigationView = (BottomNavigationView)findViewById(R.id.NavGroup);

    bottomNavigationView.setOnNavigationItemSelectedListener(
            new BottomNavigationView.OnNavigationItemSelectedListener(){

                @Override
                public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                    Fragment selectedFragment1 = null;
                    switch (item.getItemId()){
                        case R.id.groupJoined:
                            selectedFragment1 = GroupOne.newInstance();
                            break;
                        case R.id.createGroup:
                            selectedFragment1 = GroupTwo.newInstance();
                            break;
                    }

                    FragmentTransaction trans = getChildFragmentManager().beginTransaction();
                    trans.replace(R.id.groupFrame_layout, selectedFragment1);
                    trans.commit();
                    return true;

                }
            });


}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    return inflater.inflate(R.layout.fragment_item_three, container, false);

}
}

我正在调用的片段的代码

GroupOne.java

public class GroupOne extends Fragment {
public static GroupOne newInstance() {
    GroupOne fragment = new GroupOne();
    return fragment;
}

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

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_group_one, container, false);
}
}

对于GroupTwo.java

public class GroupTwo extends Fragment {
public static GroupTwo newInstance() {
    GroupTwo fragment = new GroupTwo();
    return fragment;
}

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

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_group_two, container, false);
}
}

这是我的主要活动

公共类MainActivity扩展了AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    BottomNavigationView bottomNavigationView = (BottomNavigationView)
            findViewById(R.id.NavBot);

    bottomNavigationView.setOnNavigationItemSelectedListener
            (new BottomNavigationView.OnNavigationItemSelectedListener() {
                @Override
                public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                    Fragment selectedFragment = null;
                    switch (item.getItemId()) {
                        case R.id.home:
                            selectedFragment = ItemOneFragment.newInstance();
                            break;
                        case R.id.search:
                            selectedFragment = ItemTwoFragment.newInstance();
                            break;
                        case R.id.groups:
                            selectedFragment = ItemThreeFragment.newInstance();
                            break;
                    }
                    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
                    transaction.replace(R.id.frame_layout, selectedFragment);
                    transaction.commit();
                    return true;
                }
            });

    //Manually displaying the first fragment - one time only
    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
    transaction.replace(R.id.frame_layout, ItemOneFragment.newInstance());
    transaction.commit();

    //Used to select an item programmatically
    //bottomNavigationView.getMenu().getItem(2).setChecked(true);
}

activity_main.xml

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.findforme.www.myapplication.MainActivity">

<FrameLayout
    android:id="@+id/frame_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_above="@+id/navigation"
    android:animateLayoutChanges="true"
    android:layout_below="@+id/bottomNavigationView">
</FrameLayout>

<android.support.design.widget.BottomNavigationView

    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/NavBot"
    android:layout_gravity="bottom"
    app:menu="@menu/menu_nav"
    android:background="@color/Lime"
    app:itemIconTint="@android:color/white"
    app:itemTextColor="@android:color/white"></android.support.design.widget.BottomNavigationView>

fragment_item_three.xml

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/ScrollView01"
android:layout_width="fill_parent"
android:layout_height="fill_parent">


<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:gravity="center"
    android:weightSum="1">

    <SearchView
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:id="@+id/searchGroup"
        android:scrollbarSize="10dp"/>

    <android.support.design.widget.BottomNavigationView

        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/NavGroup"
        android:layout_gravity="bottom"
        app:menu="@menu/menu_group"
        android:background="@color/Lime"
        app:itemIconTint="@android:color/white"
        app:itemTextColor="@android:color/white"></android.support.design.widget.BottomNavigationView>

    <FrameLayout
        android:id="@+id/groupFrame_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/navigation"
        android:animateLayoutChanges="true"
        android:layout_below="@+id/bottomNavigationView">
    </FrameLayout>

</LinearLayout>

fragment_group_one.xml

<FrameLayout 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"
tools:context="com.findforme.www.myapplication.GroupOne">

<!-- TODO: Update blank fragment layout -->

<TextView
    android:text="Hay salamat"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView3" />

fragment_group_two.xml

<FrameLayout 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"
tools:context="com.findforme.www.myapplication.GroupTwo">

<!-- TODO: Update blank fragment layout -->
<TextView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:text="Hay Humana" />

android

android-fragments

回答 2

Stack Overflow用户

发布于 2017-12-07 13:00:52

示例代码

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_group_two, container, false);
    TextView tv = (TextView) view.findViewById(R.id.tv)
    return view;
}

票数 1

Stack Overflow用户

发布于 2017-12-07 13:41:21

这就是我问题的答案。

 private void findViews(View view)
{
    bottomNavigationView = (BottomNavigationView)view.findViewById(R.id.NavGroup);
    bottomNavigationView.setOnNavigationItemSelectedListener(
            new BottomNavigationView.OnNavigationItemSelectedListener(){

                @Override
                public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                    Fragment selectedFragment1 = null;
                    switch (item.getItemId()){
                        case R.id.groupJoined:
                            selectedFragment1 = GroupOne.newInstance();
                            break;
                        case R.id.createGroup:
                            selectedFragment1 = GroupTwo.newInstance();
                            break;
                    }

                    FragmentTransaction trans = getFragmentManager().beginTransaction();
                    trans.replace(R.id.groupFrame_layout, selectedFragment1);
                    trans.commit();
                    return true;

                }
            });
}

然后在onCreateView中添加

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_item_three, container, false);
    findViews(view);
    return view;

}

票数 1

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/47687892

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问如何在公共类ItemThreeFragment扩展片段中使用findViewById
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