帶有帶有listview片段的標籤顯示空白屏幕

打開下面的活動時，它始終顯示一個空白屏幕。請幫助我是新來的android，我從數據庫填充我的列表，並對該數據執行一些操作，並在列表視圖中顯示它。當我將這些數據填充到listview中作爲一個單獨的活動時，它工作的很好，但是當我對碎片進行同樣的處理時，它會顯示空白屏幕。帶有帶有listview片段的標籤顯示空白屏幕

我的選項卡的活動類

package com.example.myexpensemanager; 

import com.example.myexpensemanager.adapter.TabsPagerAdapter; 
import android.app.ActionBar; 
import android.app.ActionBar.Tab; 
import android.app.FragmentTransaction; 
import android.os.Bundle; 
import android.support.v4.app.FragmentActivity; 
import android.support.v4.view.ViewPager; 

public class TabActivity extends FragmentActivity implements 
     ActionBar.TabListener { 

    private ViewPager viewPager; 
    private TabsPagerAdapter mAdapter; 
    private ActionBar actionBar; 
    // Tab titles 
    private String[] tabs = { "All", "Daily", "Weekly","Monthly" }; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_tab); 

     // Initilization 
     viewPager = (ViewPager) findViewById(R.id.pager); 
     actionBar = getActionBar(); 
     mAdapter = new TabsPagerAdapter(getSupportFragmentManager()); 

     viewPager.setAdapter(mAdapter); 
     actionBar.setHomeButtonEnabled(false); 
     actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);   

     // Adding Tabs 
     for (String tab_name : tabs) { 
      actionBar.addTab(actionBar.newTab().setText(tab_name) 
        .setTabListener(this)); 
     } 

     /** 
     * on swiping the viewpager make respective tab selected 
     * */ 
     viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() { 

      @Override 
      public void onPageSelected(int position) { 
       // on changing the page 
       // make respected tab selected 
       actionBar.setSelectedNavigationItem(position); 
      } 

      @Override 
      public void onPageScrolled(int arg0, float arg1, int arg2) { 
      } 

      @Override 
      public void onPageScrollStateChanged(int arg0) { 
      } 
     }); 
    } 

    @Override 
    public void onTabReselected(Tab tab, FragmentTransaction ft) { 

    } 

    @Override 
    public void onTabSelected(Tab tab, FragmentTransaction ft) { 
     // on tab selected 
     // show respected fragment view 
     viewPager.setCurrentItem(tab.getPosition()); 
    } 

    @Override 
    public void onTabUnselected(Tab tab, FragmentTransaction ft) { 
    } 

}

我的適配器類別

package com.example.myexpensemanager.adapter; 

import com.example.myexpensemanager.AllExpense; 
import com.example.myexpensemanager.DailyExpense; 
import com.example.myexpensemanager.MonthlyExpense; 
import com.example.myexpensemanager.WeeklyExpense; 

import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentManager; 
import android.support.v4.app.FragmentPagerAdapter; 
import android.support.v4.app.FragmentStatePagerAdapter; 

public class TabsPagerAdapter extends FragmentStatePagerAdapter{ 

    public TabsPagerAdapter(FragmentManager supportFragmentManager) { 
     // TODO Auto-generated constructor stub 
     super(supportFragmentManager); 
    } 

    @Override 
    public Fragment getItem(int arg0) { 
     // TODO Auto-generated method stub 
     switch (arg0) { 
      case 0: 

       return new AllExpense(); 
      case 1: 

       return new DailyExpense(); 
      case 2: 
       // Movies fragment activity 
       return new WeeklyExpense(); 
      case 3: 
       // Movies fragment activity 
       return new MonthlyExpense(); 
      } 

      return null; 
     } 


    @Override 
    public int getCount() { 
     // TODO Auto-generated method stub 
     return 0; 
    } 

}

我的其中一個片段類。

import java.util.ArrayList; 
import java.util.Date; 
import java.util.HashMap; 
import java.util.List; 
import java.util.Map; 
import java.util.NavigableMap; 
import java.util.TreeMap; 

import cal_helper.Calendar_Helper; 

import com.google.common.collect.ArrayListMultimap; 
import com.google.common.collect.ListMultimap; 

import android.support.v4.app.Fragment; 
import android.support.v7.app.ActionBarActivity; 
import android.content.Context; 
import android.database.Cursor; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 

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.ListView; 
import android.widget.SimpleAdapter; 

public class WeeklyExpense extends Fragment { 
    ListView lv; 
    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
      Bundle savedInstanceState) { 

     View rootView = inflater.inflate(R.layout.activity_history, container, false); 
lv = (ListView) rootView.findViewById(R.id.history_list); 

     populatedata(); 
     return rootView; 
    } 

private void populatedata() { 
    // TODO Auto-generated method stub 



//  setContentView(R.layout.activity_history); 
//  populatedata(); 
     Log.d("POint: ", "0"); 


     //tv = (TextView)findViewById(R.id.textView123); 
     Context context = getActivity().getApplicationContext(); 
     Log.d("POint: ", "05"); 
     expensedb db = new expensedb(context); 
     Log.d("POint: ", "04"); 
     Cursor cursor = db.getAllExpenses(); 
     Log.d("POint: ", "01"); 
     List<Expense> expenseList = new ArrayList<Expense>(); 
     Log.d("POint: ", "02"); 
     if (cursor.moveToFirst()) { 
      do { 
        Expense expense = new Expense(); 
       expense.setId(Integer.parseInt(cursor.getString(0))); 
       expense.setDateid(cursor.getString(1)); 
       expense.setDescription(cursor.getString(2)); 
       expense.setAmount(Integer.parseInt(cursor.getString(3))); 
       expense.setDate(cursor.getString(4)); 
       expense.setDateStamp(cursor.getString(5)); 
       expense.setCat_id(Integer.parseInt(cursor.getString(6))); 
       // Adding contact to list 
       expenseList.add(expense); 
      } while (cursor.moveToNext()); 
     } 
     Log.d("POint: ", "1"); 
ListMultimap<Integer, Expense> myMultimap = ArrayListMultimap.create(); 
Map<Integer, Date> myMap = new TreeMap<Integer,Date>(); 
Calendar_Helper cal = new Calendar_Helper(); 
for (Expense x : expenseList) { 
    Date date=cal.strtodate(x.getDate()); 
    int key =cal.weekOfYear(date) + cal.year(date)*100; 
    myMultimap.put(key,x); 
    myMap.put(key,date); 
} 
Log.d("POint: ", "2"); 
ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>(); 
NavigableMap<Integer, Date> myMap1=((TreeMap<Integer, Date>) myMap).descendingMap(); 
for(Integer key : myMap1.keySet()){ 
    List<Expense> list = new ArrayList<Expense>(); 
    list = myMultimap.get(key); 
    int amount = cal_amount(list); 
    int week = cal.weekOfYear(myMap.get(key)); 
    int year = cal.year(myMap.get(key)); 
    HashMap<String, String> map = new HashMap<String, String>(); 
    map.put("startdate", cal.startDate(week, year)); 
    map.put("enddate",cal.endDate(week, year)); 
    map.put("amount", Integer.toString(amount)); 
    mylist.add(map); 
} 
Log.d("POint: ", "4"); 

//now i have the all key values 
SimpleAdapter adapter = new SimpleAdapter(context, mylist, R.layout.activity_week, 
     new String[] {"startdate", "enddate", "amount"}, new int[] {R.id.tv_week, R.id.tv_week2, R.id.tv_Wamount}); 
lv.setAdapter(adapter); 
    } 



private int cal_amount(List<Expense> list) { 
    int amount=0; 
    for(Expense x: list) 
    { 
     amount += x.getAmount(); 
    } 
    return amount; 
} 
}

來源

2014-10-16 ayush bagaria

你數應爲4

public int getCount() { 
     // TODO Auto-generated method stub 
     return 4; 
    }

來源

2014-10-17 07:02:29

帶有帶有listview片段的標籤顯示空白屏幕

回答

相關問題