如何將光標從片段轉換爲新的活動？

Question

我有一個工作ListView，在一個片段和ListItem被點擊時
我想鏈接數據到一個新的活動。我得到我的db對象
不能轉換到DB光標

import android.app.ActionBar; 
import android.app.FragmentTransaction; 
import android.content.Intent; 
import android.database.Cursor; 
import android.os.Bundle; 
import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentActivity; 
import android.support.v4.app.FragmentManager; 
import android.support.v4.app.FragmentPagerAdapter; 
import android.support.v4.view.ViewPager; 
import android.util.Log; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.Button; 
import android.widget.DatePicker; 
import android.widget.EditText; 
import android.widget.ListView; 
import android.widget.RadioButton; 
import android.widget.TextView; 
import android.widget.Toast; 

import com.mlaffan.giftpal.sqlite.adapter.PersonAdapter; 
import com.mlaffan.giftpal.sqlite.db.DatabaseHelper; 
import com.mlaffan.giftpal.sqlite.db.Person; 

import java.util.ArrayList; 

public class MainActivity extends FragmentActivity implements ActionBar.TabListener { 
    public PersonAdapter personAdapter; 
    /** 
    * The {@link android.support.v4.view.PagerAdapter} that will provide fragments for each of the 
    * four primary sections of the app. We use a {@link android.support.v4.app.FragmentPagerAdapter} 
    * derivative, which will keep every loaded fragment in memory. If this becomes too memory 
    * intensive, it may be best to switch to a {@link android.support.v4.app.FragmentStatePagerAdapter}. 
    */ 
    AppSectionsPagerAdapter mAppSectionsPagerAdapter; 

    /** 
    * The {@link ViewPager} that will display the four primary sections of the app, one at a 
    * time. 
    */ 
    ViewPager mViewPager; 

    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     DatabaseHelper dbHelp = new DatabaseHelper(getApplicationContext()); 

     // Create the adapter that will return a fragment for each of the four primary sections 
     // of the app. 
     mAppSectionsPagerAdapter = new AppSectionsPagerAdapter(getSupportFragmentManager()); 

     // Set up the action bar. 
     final ActionBar actionBar = getActionBar(); 

     // Specify that the Home/Up button should not be enabled, since there is no hierarchical 
     // parent. 
     actionBar.setHomeButtonEnabled(false); 

     // Specify that we will be displaying tabs in the action bar. 
     actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); 

     // Set up the ViewPager, attaching the adapter and setting up a listener for when the 
     // user swipes between sections. 
     mViewPager = (ViewPager) findViewById(R.id.pager); 
     mViewPager.setAdapter(mAppSectionsPagerAdapter); 
     mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() { 
      @Override 
      public void onPageSelected(int position) { 
       // When swiping between different app sections, select the corresponding tab. 
       // We can also use ActionBar.Tab#select() to do this if we have a reference to the 
       // Tab. 
       actionBar.setSelectedNavigationItem(position); 
      } 
     }); 

     // For each of the sections in the app, add a tab to the action bar. 
     for (int i = 0; i < mAppSectionsPagerAdapter.getCount(); i++) { 
      // Create a tab with text corresponding to the page title defined by the adapter. 
      // Also specify this Activity object, which implements the TabListener interface, as the 
      // listener for when this tab is selected. 
      actionBar.addTab(
        actionBar.newTab() 
          .setText(mAppSectionsPagerAdapter.getPageTitle(i)) 
          .setTabListener(this)); 
     } 
    } 

    @Override 
    public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { 
    } 

    @Override 
    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { 
     // When the given tab is selected, switch to the corresponding page in the ViewPager. 
     mViewPager.setCurrentItem(tab.getPosition()); 
    } 

    @Override 
    public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) { 
    } 

    /** 
    * A {@link FragmentPagerAdapter} that returns a fragment corresponding to one of the primary 
    * sections of the app. 
    */ 
    public static class AppSectionsPagerAdapter extends FragmentPagerAdapter { 

     public AppSectionsPagerAdapter(FragmentManager fm) { 
      super(fm); 
     } 

     @Override 
     public Fragment getItem(int i) { 
      switch (i) { 
       case 0: 
        // The first section of the app is the most interesting -- it offers 
        // a launchpad into the other demonstrations in this example application. 
        return new LaunchpadSectionFragment(); 

       case 1: 
        return new AddPeopleFragment(); 

       case 2: 
        return new PeopleSectionFragment(); 

       default: 
        return new SnapGiftFragment(); 

//    default: 
        // The other sections of the app are dummy placeholders. 
//     Fragment fragment = new DummySectionFragment(); 
//     Bundle args = new Bundle(); 
//     args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, i + 1); 
//     fragment.setArguments(args); 
//     return fragment; 
      } 
     } 

     @Override 
     public int getCount() { 
      return 4; 
     } 

     @Override 
     public CharSequence getPageTitle(int position) { 
      if (position == 0) { 
       return "Events"; 
      } else if (position == 1) { 
       return "Add People"; 
      } else if (position == 2) { 
       return "Your People"; 
      } else { 
       return "Snap Gift"; 
      } 
     } 
    } 

    /** 
    * A fragment that launches other parts of the demo application. 
    */ 
    public static class LaunchpadSectionFragment extends Fragment { 

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
           Bundle savedInstanceState) { 
      View rootView = inflater.inflate(R.layout.fragment_section_launchpad, container, false); 

      // Demonstration of navigating to external activities. 
      rootView.findViewById(R.id.demo_external_activity) 
        .setOnClickListener(new View.OnClickListener() { 
         @Override 
         public void onClick(View view) { 
          // Create an intent that asks the user to pick a photo, but using 
          // FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET, ensures that relaunching 
          // the application from the device home screen does not return 
          // to the external activity. 
          Intent externalActivityIntent = new Intent(Intent.ACTION_PICK); 
          externalActivityIntent.setType("image/*"); 
          externalActivityIntent.addFlags(
            Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET); 
          startActivity(externalActivityIntent); 
         } 
        }); 

      // link to Profiles Activitys. 
      rootView.findViewById(R.id.profiles_button) 
        .setOnClickListener(new View.OnClickListener() { 
         @Override 
         public void onClick(View view) { 
          Intent intent = new Intent(getActivity(), ProfileActivity.class); 
          startActivity(intent); 
         } 
        }); 

      return rootView; 
     } 
    } 

    /** 
    * A fragment lets the user create a new profile. 
    */ 
    public static class AddPeopleFragment extends Fragment { 
     private String sex = "male"; 
     private EditText firstName; 
     private EditText lastName; 
     private DatePicker birthday; 

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
           Bundle savedInstanceState) { 
      View rootView = inflater.inflate(R.layout.fragment_add_people, container, false); 
      return rootView; 
     } 

     @Override 
     public void onViewCreated(View view, final Bundle bundle) { 
      super.onViewCreated(view, bundle); 
      firstName = (EditText) view.findViewById(R.id.firstName); 
      lastName = (EditText) view.findViewById(R.id.lastName); 
      RadioButton male = (RadioButton) view.findViewById(R.id.male); 
      RadioButton female = (RadioButton) view.findViewById(R.id.female); 
      birthday = (DatePicker) view.findViewById(R.id.datePicker); 
      Button button = (Button) view.findViewById(R.id.button); 

      male.setOnClickListener(new View.OnClickListener() { 
       @Override 
       public void onClick(View v) { 
        sex = "male"; 
       } 
      }); 

      female.setOnClickListener(new View.OnClickListener() { 
       @Override 
       public void onClick(View v) { 
        sex = "female"; 
       } 
      }); 

      button.setOnClickListener(new View.OnClickListener() { 
       @Override 
       public void onClick(View v) { 
        String fName = firstName.getText().toString(); 
        String lName = lastName.getText().toString(); 
        int day = birthday.getDayOfMonth(); 
        int month = birthday.getMonth(); 
        int year = birthday.getYear(); 
        Person person = new Person(); 
        person.setFirstName(fName); 
        person.setLastName(lName); 
        person.setSex(sex); 
        person.setBirthday("" + day + "/" + month + "/" + year); 
        DatabaseHelper dbHelper = new DatabaseHelper(getActivity().getApplicationContext()); 
        dbHelper.addPerson(person); 
        Toast.makeText(getActivity(), "Profile added!", Toast.LENGTH_SHORT).show(); 

        if (PeopleSectionFragment.adapter != null) { 
         PeopleSectionFragment.adapter.add(person); 
        } 

       } 
      }); 
     } 
    } 

    /** 
    * A fragment that contains a list of profiles. 
    */ 
    public static class PeopleSectionFragment extends Fragment { 

     public static PersonAdapter adapter; 

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
           Bundle savedInstanceState) { 
      View rootView = inflater.inflate(R.layout.fragment_people, container, false); 
      return rootView; 
     } 

     @Override 
     public void onViewCreated(View view, Bundle bundle) { 
      super.onViewCreated(view, bundle); 
      DatabaseHelper dbHelp = new 
        DatabaseHelper(getActivity().getApplicationContext()); 
      ArrayList<Person> people = dbHelp.getPeople(); 
      adapter = new PersonAdapter(getActivity().getApplicationContext(), 
        R.layout.fragment_people_list_item, people); 
      ListView listView = (ListView) getActivity().findViewById(R.id.list); 
      listView.setAdapter(adapter); 
      listView.setOnItemClickListener(new ItemClicked()); 
     } 

     class ItemClicked implements AdapterView.OnItemClickListener { 
      @Override 
      public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
       Person person = adapter.getItem(position); 
       Log.i("ItemClicked", person.getFirstName()); 

       // When a listitem is clicked 
       Intent intent = new Intent(getActivity(), Profile.class); 
       Cursor cursor = (Cursor) person; 
       intent.putExtra("PERSON_ID", cursor.getInt(cursor.getColumnIndex("_id"))); 
       startActivity(intent); 


      } 
     } 


    } 


    public static class SnapGiftFragment extends Fragment { 

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
           Bundle savedInstanceState) { 
      View rootView = inflater.inflate(R.layout.fragment_snap_gift, container, false); 
      return rootView; 
     } 
    } 
} 

此代碼似乎是個麻煩的是一個錯誤;

Intent intent = new Intent(getActivity(), Profile.class); 
        Cursor cursor = (Cursor) person; 
        intent.putExtra("PERSON_ID", cursor.getInt(cursor.getColumnIndex("_id"))); 
        startActivity(intent); 

這是錯誤信息;

05-05 12:27:54.575 2231-2231/? E/AndroidRuntime﹕ FATAL EXCEPTION: main 
    Process: com.mlaffan.giftpal, PID: 2231 
    java.lang.ClassCastException: com.mlaffan.giftpal.sqlite.db.Person cannot be cast to android.database.Cursor 
      at com.mlaffan.giftpal.MainActivity$PeopleSectionFragment$ItemClicked.onItemClick(MainActivity.java:306) 
      at android.widget.AdapterView.performItemClick(AdapterView.java:300) 
      at android.widget.AbsListView.performItemClick(AbsListView.java:1143) 
      at android.widget.AbsListView$PerformClick.run(AbsListView.java:3044) 
      at android.widget.AbsListView$3.run(AbsListView.java:3833) 
      at android.os.Handler.handleCallback(Handler.java:739) 
      at android.os.Handler.dispatchMessage(Handler.java:95) 
      at android.os.Looper.loop(Looper.java:135) 
      at android.app.ActivityThread.main(ActivityThread.java:5221) 
      at java.lang.reflect.Method.invoke(Native Method) 
      at java.lang.reflect.Method.invoke(Method.java:372) 
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 

這是目標活動;

import android.app.Activity; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.os.Bundle; 
import android.widget.TextView; 

import com.mlaffan.giftpal.sqlite.db.DatabaseHelper; 

/** 
* Created by Mark on 05/05/2015. 
*/ 
public class Profile extends Activity { 

    protected TextView profileFirst; 
    protected TextView profileLast; 
    protected TextView profileBirthday; 
    protected TextView profileSex; 
    protected int profileId; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.profile_view); 

     profileId = getIntent().getIntExtra("PERSON_ID", 0); 
     SQLiteDatabase db = (new DatabaseHelper(this)).getWritableDatabase(); 
     Cursor cursor = db.rawQuery("SELECT _id, firstName, lastName, sex, birthday FROM people WHERE _id = ?", 
       new String[]{""+profileId}); 

     if (cursor.getCount() == 1){ 
      cursor.moveToFirst(); 

      profileFirst = (TextView) findViewById(R.id.profileFirst); 
      profileFirst.setText(cursor.getString(cursor.getColumnIndex("firstName"))); 

      profileLast = (TextView) findViewById(R.id.lastName); 
      profileLast.setText(cursor.getString(cursor.getColumnIndex("lastName"))); 

      profileSex = (TextView) findViewById(R.id.profileSex); 
      profileSex.setText(cursor.getString(cursor.getColumnIndex("sex"))); 

      profileBirthday = (TextView) findViewById(R.id.profileBirthday); 
      profileBirthday.setText(cursor.getString(cursor.getColumnIndex("birthday"))); 


     } 
    } 
} 

道歉，如果這是一個混亂的，如果我需要提供更多的信息，請問。

Answer 1

擴展您的Person class爲Serializable比你可以試試這個方法：

Person person = (Person)adapter.getItem(position); 
    Intent intent = new Intent(getActivity(), Profile.class);      
    intent.putExtra("person", person); 
    startActivity(intent); 

現在，在您Profile activity，做到這一點的方法：

Person person; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.profile_view); 

     person = (Person) getIntent().getSerializableExtra("person");   

     profileFirst = (TextView) findViewById(R.id.profileFirst); 
     profileFirst.setText(person.firstName); 

     profileLast = (TextView) findViewById(R.id.lastName); 
     profileLast.setText(person.lastName"); 
     ... 
     ...   
    }