【发布时间】：2016-08-30 09:56:25
【问题描述】：
我在我的活动中添加了两个片段，片段 1 包含一个按钮，片段 2 包含一个 TextView，当我单击片段 1 中的按钮时，它的计数器会增加并在片段 2 的 TextView 中显示结果。 我正在处理 saveInstanceState 并保存计数器和文本以防屏幕旋转。但是仍然存在错误.......错误是当我运行应用程序时它工作正常，但是一旦我旋转屏幕，它的 onclick 方法根本不会调用。我被困在这里，请帮忙。
public class FragmentA extends Fragment{
Button button;
int counter;
Communicator communicator;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_a,container,false);
button = (Button) view.findViewById(R.id.button);
if(savedInstanceState == null)
counter = 0;
else{
counter = savedInstanceState.getInt("Counter",0);
}
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
counter++;
communicator.respond("Button was clicked "+counter+ " times");
}
});
return view;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("Counter",counter);
}
public void setCommunicator(Communicator communicator){
this.communicator = communicator;
}
interface Communicator{
public void respond(String data);
}
}
我已经尝试了将按钮与 onCreateView() 和 onActivityCreate() 按钮中的侦听器绑定的两个选项，问题就在那里。
public class FragmentB extends Fragment{
TextView textView;
String data;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_b, container, false);
if (savedInstanceState != null) {
textView = (TextView) view.findViewById(R.id.textView);
data = savedInstanceState.getString("text");
textView.setText(data);
}
return view;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
textView = (TextView) getActivity().findViewById(R.id.textView);
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putString("text", data);
}
public void changeData(String data){
this.data = data;
textView.setText(data);
}
}
这是我使用这些片段的活动......
public class MainActivity extends AppCompatActivity implements FragmentA.Communicator{
FragmentManager fragmentManager;
FragmentTransaction fragmentTransaction;
FragmentA fragmentA;
FragmentB fragmentB;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragmentManager = getFragmentManager();
fragmentTransaction = fragmentManager.beginTransaction();
fragmentA = new FragmentA();
fragmentB = new FragmentB();
fragmentTransaction.add(R.id.fragment_container1,fragmentA,"Najam");
fragmentTransaction.add(R.id.fragment_container2,fragmentB,"Najam");
fragmentTransaction.commit();
fragmentA.setCommunicator(this);
}
@Override
public void respond(String data) {
//set the text of fragment_B
fragmentB.changeData(data);
}
}
这里是简单的 XML 文件
这是给片段A的
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#00FFB0">
<Button
android:layout_margin="10dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Click me"
android:id="@+id/button" />
</LinearLayout>
这是给片段B的
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#AAA333">
<TextView
android:layout_width="match_parent"
android:layout_margin="10dp"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="you clicked the button 0 times"
android:id="@+id/textView" />
</LinearLayout>
这是活动
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
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"
android:background="#FFBB00"
android:id="@+id/main_layout"
tools:context="com.najam.fragments1.MainActivity">
<FrameLayout android:id="@+id/fragment_container1"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<FrameLayout android:id="@+id/fragment_container2"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
</LinearLayout>
【问题讨论】：
-
如何初始化
communicator？找不到执行此操作的代码。 -
感谢@karan，但我担心解决方案并非如此。
-
我已经在MainActivity中初始化了communicator
标签： android android-fragments onclicklistener