我正在尝试创建一个Android Wear应用程序,它只有一个活动,并且其中包含一个片段。我希望能够根据按钮点击或其他用户操作切换片段。
我可以很好地替换片段;但是,当我从屏幕的左侧向右侧滑动时,应用程序会关闭。我预期这个手势应该像返回按钮一样,而不是退出应用程序。
主要活动
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.wearable.view.WatchViewStub;
public class MainActivity extends FragmentActivity implements FragmentChangeListener {
int fragmentContainerId;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
final WatchViewStub stub = (WatchViewStub)findViewById(R.id.watch_view_stub);
// instialize the fragment to the loading page
stub.setOnLayoutInflatedListener(new WatchViewStub.OnLayoutInflatedListener() {
@Override
public void onLayoutInflated(WatchViewStub watchViewStub) {
fragmentContainerId = R.id.fragmentContainer;
if (watchViewStub.findViewById(R.id.fragmentContainer) != null) {
Fragment1 fragment1= new Fragment1 ();
// In case this activity was started with special instructions from an Intent,
// pass the Intent's extras to the fragment as arguments
fragment1.setArguments(getIntent().getExtras());
// Add the fragment to the 'fragment_container'
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.fragmentContainer, fragment1).addToBackStack(null);
fragmentTransaction.commit();
}
}
});
}
@Override
public void replaceFragment(Fragment fragment) {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.fragmentContainer, fragment, fragment.toString()).addToBackStack(null);
System.out.println("Entry count in backstack is: " + fragmentManager.getBackStackEntryCount());
fragmentTransaction.commit();
}
}
片段 1
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
public class Fragment1 extends Fragment {
public Fragment1() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment1,
container, false);
Button button1= (Button)view.findViewById(R.id.button1);
button1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Fragment2 fragment2= new Fragment2 ();
FragmentChangeListener fc=(FragmentChangeListener)getActivity();
fc.replaceFragment(fragment2);
}
});
return view;
}
}
片段 2
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
/**
* A simple {@link Fragment} subclass.
*/
public class Fragment2 extends Fragment {
public Fragment2() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v =inflater.inflate(R.layout.fragment2, container, false);
return v;
}
}
FragmentChangeListner
import android.support.v4.app.Fragment;
public interface FragmentChangeListener
{
public void replaceFragment(Fragment fragment);
}
当我通过按钮点击从Fragment1导航到Fragment2时,如何在不退出应用程序的情况下导航回Fragment1?