【发布时间】：2017-10-15 17:26:44
【问题描述】：
我在主要活动中有一个图像，当单击此图像时，我想显示具有列表视图的片段 A。
当单击此 listView 的一个项目时，我想用具有 textview 的 fragmentB 替换 fragmentA，并且我想在此 textview 中显示与单击的列表项关联的文本。
所以在主要活动我有这个：
public class MainActivity extends AppCompatActivity implements Listener{
private ImageView img;
private String text;
FragmentManager fragmentManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragmentManager = getFragmentManager();
img = (ImageView) findViewById(R.id.imageView);
}
public void AddFragmentA(View view) {
FragmentA fragmentA = new FragmentA();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.add(R.id.containerFragmentA, new FragmentA(), "fragA");
transaction.commit();
}
public void AddFragmentB() {
FragmentB fragment = new FragmentB();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.add(R.id.containerFragmentB, new FragmentA(), "fragB");
transaction.commit();
}
@Override
public void addText(String text) {
this.text = text;
Toast.makeText(this, "Text received in Activity:" +text, Toast.LENGTH_SHORT).show();
sendDataToFragmentB();
}
public void sendDataToFragmentB(){
FragmentB fragmentB = (FragmentB) fragmentManager.findFragmentByTag("fragB");
fragmentB.addText(text);
}
}
注意：此时 addText() 中的 toast 出现了正确的文本，因此在 Activity 中成功接收到列表视图的文本。
问题：现在如何用fragmentB替换fragmentA，并在activity中用接收到的文本显示textview，而不是显示fragmentA的listview？
下面是完整的例子。
FragmentA 类：
public class FragmentA extends Fragment{
private ListView listItems;
private String[] items = {
"item1",
"item2",
"item3",
"item4"
};
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment, container, false);
return view;
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
listItems = (ListView) getView().findViewById(R.id.listviewInFragment);
ArrayAdapter<String> adapter =
new ArrayAdapter<String>(getActivity().getApplicationContext(),
android.R.layout.simple_list_item_1, android.R.id.text1, items);
listItems.setAdapter(adapter);
listItems.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
int positionCode = i;
String clickedValue = (String) adapterView.getItemAtPosition(i);
Listener listener = (Listener) getActivity();
listener.addText(clickedValue);
}
});
}
}
FramentB：
public class FragmentB extends Fragment {
private TextView tv;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_b, container, false);
tv = (TextView) getView().findViewById(R.id.textView);
return view;
}
public void addText(String text) {
String result = text;
tv.setText(result);
}
}
主要活动 xml：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:srcCompat="@drawable/image"
android:onClick="AddFragmentA"
tools:layout_editor_absoluteX="0dp"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginBottom="8dp" />
<FrameLayout
android:id="@+id/containerFragmentA"
android:layout_width="0dp"
android:layout_height="300dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintHorizontal_bias="0.0"
tools:layout_editor_absoluteY="1dp">
</FrameLayout>
<FrameLayout
android:id="@+id/containerFragmentB"
android:layout_width="0dp"
android:layout_height="300dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintHorizontal_bias="0.0"
tools:layout_editor_absoluteY="1dp">
</FrameLayout>
</android.support.constraint.ConstraintLayout>
对 xml 进行分段：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#0ff">
<ListView
android:layout_width="368dp"
android:layout_height="495dp"
android:layout_marginLeft="8dp"
android:layout_marginStart="16dp"
android:id="@+id/listviewInFragment"/>
</android.support.constraint.ConstraintLayout>
片段 b xml：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ff0">
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="300dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
/>
</android.support.constraint.ConstraintLayout>
【问题讨论】：
-
检查我的答案here，您可以使用带有两个片段的 ViewPager，通过触摸限制滚动，只需在 ListView 的项目单击上使用提供的解决方案。横向滚动会给你的 UI 一个很好的效果，而不是替换