Question

我在片段中进行沟通时遇到问题，以下是我的代码：

ListPolicies Fragment

public class ListPolicies extends ListFragment implements AdapterView.OnItemClickListener{


String polnames;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    return inflater.inflate(R.layout.list_policies, null, false);


}

public String polName(String name){


    if(name!=null) {
        polnames = name;


    }
    Log.d("Luffy", "Pos" +polnames);
        return polnames;

}

    String polname = polName(polnames);


@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
        if (polname != null) {
            Log.d("Luffy", "Position 00");
            if (polname.equalsIgnoreCase("0")) {
                Log.d("Luffy", "Position 0");
                ArrayAdapter adapter = ArrayAdapter.createFromResource(getActivity(), R.array.Engineering_Insurance, android.R.layout.simple_list_item_1);
                setListAdapter(adapter);
                getListView().setOnItemClickListener(this);
            }
        }

}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
    Toast.makeText(getActivity(), "Uploaded :" + position, Toast.LENGTH_LONG).show();
}
}

ViewPolicy片段

public class ViewPolicyFragment extends ListFragment implements AdapterView.OnItemClickListener{


String[] menutitles;
TypedArray menuIcons;

PolicyCommunicator comm;

CustomAdapter adapter;
private List<rowItem> rowItems;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    return inflater.inflate(R.layout.view_policy_fragment, null, false);
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {

    super.onActivityCreated(savedInstanceState);

    menutitles = getResources().getStringArray(R.array.Insurance);
    menuIcons = getResources().obtainTypedArray(R.array.icons);

    rowItems = new ArrayList<rowItem>();

    for (int i = 0; i < menutitles.length; i++) {
        rowItem items = new rowItem(menutitles[i], menuIcons.getResourceId(
                i, -1));

        rowItems.add(items);
    }

    adapter = new CustomAdapter(getActivity(), rowItems);
    setListAdapter(adapter);
    comm = (PolicyCommunicator) getActivity();
    getListView().setOnItemClickListener(this);

}

@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
                        long id) {
    comm.policyName("" +position );
     if(menutitles[position].equalsIgnoreCase("Engineering Insurance")){
         Toast.makeText(getActivity(), "You have Clicked on Engineering Insurance", Toast.LENGTH_SHORT)
                 .show();
     }

    if(menutitles[position].equalsIgnoreCase("Fire Insurance")){
        Toast.makeText(getActivity(), "You have Clicked on Fire Insurance", Toast.LENGTH_SHORT)
                .show();
    }

    if(menutitles[position].equalsIgnoreCase("Liability Insurance")){
        Toast.makeText(getActivity(), "You have Clicked on Liability Insurance", Toast.LENGTH_SHORT)
                .show();
    }

}



}

和我使用已实施方法的活动

public class AfterLoginActivity extends AppCompatActivity implements PolicyCommunicator {


Toolbar toolbar;
FragmentManager manager;
Intent intent= null, chooser= null;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.after_login_activity);
    toolbar = (Toolbar) findViewById(R.id.app_bar);
    setSupportActionBar(toolbar);
    manager = getFragmentManager();
    AfterLoginAboutFragment fragViewPolicy = new AfterLoginAboutFragment();
    FragmentTransaction transaction = manager.beginTransaction();
    transaction.add(R.id.linearLayoutLoginFragment, fragViewPolicy, "View Policy");
    transaction.commit();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}


public void addLoginAboutFragment (View v){
    AfterLoginAboutFragment fragViewPolicy = new AfterLoginAboutFragment();
    FragmentTransaction transaction = manager.beginTransaction();
    transaction.replace(R.id.linearLayoutLoginFragment, fragViewPolicy, "View Policy");
    transaction.commit();

}

public void addViewPolicyFragment (View v){
    ViewPolicyFragment fragViewPolicy = new ViewPolicyFragment();
    FragmentTransaction transaction = manager.beginTransaction();
    transaction.replace(R.id.linearLayoutLoginFragment, fragViewPolicy, "View Policy");
    transaction.commit();
}

public void addMyProfile (View v){
    MyProfileFragment fragProfile = new MyProfileFragment();
    FragmentTransaction transaction = manager.beginTransaction();
    transaction.replace(R.id.linearLayoutLoginFragment, fragProfile, "My profile");
    transaction.commit();
}

public void addMyPolicy (View v){
    MyPolicyFragment fragMyPolicy = new MyPolicyFragment();
    FragmentTransaction transaction = manager.beginTransaction();
    transaction.replace(R.id.linearLayoutLoginFragment, fragMyPolicy, "My Policy");
    transaction.commit();
}

public void addUploadFragment (View v){
    UploadPhotoFragment fragUpload = new UploadPhotoFragment();
    FragmentTransaction transaction = manager.beginTransaction();
    transaction.replace(R.id.linearLayoutLoginFragment, fragUpload, "Uploaded Policy");
    transaction.commit();
}

public void addUploadedFragment (View v){
    UploadedPolicyFragment fragUploaded = new UploadedPolicyFragment();
    FragmentTransaction transaction = manager.beginTransaction();
    transaction.replace(R.id.linearLayoutLoginFragment, fragUploaded, "Uploaded Policy");
    transaction.commit();
}



@Override
public void policyName(String name) {
    Log.d("Luffy","Inside PolicyName AfterLogin");
    ListPolicies fragList = new ListPolicies();
    FragmentTransaction transaction = manager.beginTransaction();
    fragList.polName(name);
    transaction.replace(R.id.linearLayoutLoginFragment, fragList, "Uploaded Policy");
    transaction.commit();
}
}

输出：

10-28 14:00:18.400 2174-2174/onepiece.luffy.investaccui D/Luffy: Inside PolicyName AfterLogin
10-28 14:00:18.400 2174-2174/onepiece.luffy.investaccui D/Luffy: Posnull
10-28 14:00:18.400 2174-2174/onepiece.luffy.investaccui D/Luffy: Pos0

我希望输出为：

10-28 14:00:18.400 2174-2174/onepiece.luffy.investaccui D/Luffy: Inside PolicyName AfterLogin
10-28 14:00:18.400 2174-2174/onepiece.luffy.investaccui D/Luffy: Pos0

所以我可以调用我的Engineering_insurance listView

需要你帮助的人...... 提前致谢

Answer 1

String polname = polName(polnames);

用于创建polname字符串。

public String polName(String name){


if(name!=null) {
    polnames = name;


}
Log.d("Luffy", "Pos" +polnames);
    return polnames;

}

是所描述的方法。如果名字！= null polonaise = name。

来自

String polname = polName(polnames);

参数是“polonames”变量，在此处声明

String polnames;

但从未初始化

为什么在将一个片段与另一个片段进行通信时，输出为null？

1 个答案: