Android里做一个RadioGroup实现底部导航页面,遇到了这样的问题:
FATAL EXCEPTION: main
java.lang.IllegalStateException: Fragment null must be a public static class to be properly recreated from instance state.
at android.support.v4.app.BackStackRecord.doAddOp(BackStackRecord.java:435)
at android.support.v4.app.BackStackRecord.replace(BackStackRecord.java:481)
at android.support.v4.app.BackStackRecord.replace(BackStackRecord.java:472)
at com.example.wu.mobileplayer.Activity.Activity.MainActivity.setFragment(MainActivity.java:72)
at com.example.wu.mobileplayer.Activity.Activity.MainActivity.onCheckedChanged(MainActivity.java:65)
at android.widget.RadioGroup.setCheckedId(RadioGroup.java:174)
at android.widget.RadioGroup.access$600(RadioGroup.java:54)
at android.widget.RadioGroup$CheckedStateTracker.onCheckedChanged(RadioGroup.java:358)
at android.widget.CompoundButton.setChecked(CompoundButton.java:139)
at android.widget.CompoundButton.toggle(CompoundButton.java:91)
at android.widget.RadioButton.toggle(RadioButton.java:76)
at android.widget.CompoundButton.performClick(CompoundButton.java:103)
at android.view.View$PerformClick.run(View.java:18803)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5493)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1209)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1025)
at dalvik.system.NativeStart.main(Native Method)
代码的一部分:
public class MainActivity extends FragmentActivity implements RadioGroup.OnCheckedChangeListener{
private RadioGroup radioGroup;
private ArrayList basePagers;
private int position;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
radioGroup = (RadioGroup) findViewById(R.id.rg_selector);
radioGroup.check(R.id.rb_video);
basePagers = new ArrayList<>();
basePagers.add(new VideoPager(this));
basePagers.add(new AudioPager(this));
basePagers.add(new NetVideoPager(this));
basePagers.add(new NetAudioPager(this));
//设置监听
radioGroup.setOnCheckedChangeListener(this);
}
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
switch (checkedId) {
case R.id.rb_video:
position = 0;
break;
case R.id.rb_audio:
position=1;
break;
case R.id.rb_net_video:
position=2;
break;
case R.id.rb_net_audio:
position=3;
break;
}
setFragment();
}
private void setFragment() {
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction ft = manager.beginTransaction();
ft.replace(R.id.fl_content,new Fragment(){
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
BasePager basePager = getBasePager();
if(basePager!=null) {
return basePager.rootView;
}
return null;
}
});
ft.commit();
}
private BasePager getBasePager() {
BasePager basePager = basePagers.get(position);
if(basePager!=null && !basePager.isinitData) {
basePager.isinitData = true;
basePager.initData();
}
return basePager;
}