我需要計數我的片段,我使用getbackstackentrycount,但它總是返回0.有人能告訴我什麼是我的代碼錯了嗎?爲什麼方法getBackStackEntryCount總是返回0
這裏我的代碼MainActivity.java
package com.example.bams.taskagain;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import com.example.bams.taskagain.Fragment.FragmentOne;
public class MainActivity extends AppCompatActivity {
Button btn;
FragmentManager fm = getFragmentManager();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn = (Button) findViewById(R.id.fragOne);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
fm.beginTransaction().add(R.id.content, new FragmentOne()).addToBackStack("aa").commit();
//Toast.makeText(getBaseContext(), "fuck", Toast.LENGTH_LONG).show();
}
});
}
}
,這裏是我的fragment
類
package com.example.bams.taskagain.Fragment;
import android.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.example.bams.taskagain.R;
/**
* Created by jack on 25/02/2017.
*/
public class FragmentOne extends Fragment {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
System.out.println("Total back stack "+ ((AppCompatActivity)getActivity()).getSupportFragmentManager().getBackStackEntryCount());
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_one,container,false);
return rootView;
}
}
有人可以幫助我與我的代碼? 我只想得到我的分數有的BackStack數。
看起來像你錯過了活動 –