单击收藏夹按钮时更新列表视图
Posted
技术标签:
【中文标题】单击收藏夹按钮时更新列表视图【英文标题】：update listview when click favorites button 【发布时间】：2015-07-31 11:28:39 【问题描述】：我想在单击ListViewAdapter 类中的按钮 btn 时，更新我的 sqlite 并更改 background of btn ，当 MainActivity 启动并首先单击按钮时，是正确的。但是当我滚动列表时，btn 的背景会恢复到原来的状态，此外，当第二次单击按钮时，不会进行任何更改。
换句话说，不要更新我的列表视图。如何解决？
我在哪里以及如何使用adapter.notifyDataSetChanged();
点击ListViewAdapter 之后？如何在 myListViewAdapter 上获取 adapter at MyActivity
public class ListViewAdapter extends BaseAdapter
// Declare Variables
Context mContext;
LayoutInflater inflater;
private List<myitems> worldpopulationlist = null;
private ArrayList<myitems> arraylist;
int myfavorit =0;
DataBaseHelper myDbHelper;
SQLiteDatabase db;
Cursor mCursor;
public ListViewAdapter(Context context, List<myitems> worldpopulationlist)
mContext = context;
this.worldpopulationlist = worldpopulationlist;
inflater = LayoutInflater.from(mContext);
this.arraylist = new ArrayList<myitems>();
this.arraylist.addAll(worldpopulationlist);
public class ViewHolder
TextView rank;
TextView country;
TextView population;
Button btn;
@Override
public int getCount()
return worldpopulationlist.size();
@Override
public myitems getItem(int position)
return worldpopulationlist.get(position);
@Override
public long getItemId(int position)
return position;
public View getView(final int position, View view, ViewGroup parent)
final ViewHolder holder;
if (view == null)
holder = new ViewHolder();
view = inflater.inflate(R.layout.myitems_list, null);
// Locate the TextViews in listview_item.xml
holder.rank = (TextView) view.findViewById(R.id.txt25);
holder.btn=(Button) view.findViewById(R.id.btnfavor);
holder.country = (TextView) view.findViewById(R.id.txt26);
view.setTag(holder);
else
holder = (ViewHolder) view.getTag();
holder.rank.setText(worldpopulationlist.get(position).gettitle());
holder.country.setText(worldpopulationlist.get(position).getshomare()+"-");
myfavorit=worldpopulationlist.get(position).getfavoir();
if(myfavorit==0)
holder.btn.setBackgroundResource(R.drawable.ic_launcher);
else
holder.btn.setBackgroundResource(R.drawable.star);
holder.btn.setOnClickListener(new OnClickListener()
@Override
public void onClick(View v)
myDbHelper = new DataBaseHelper(mContext.getApplicationContext());
myDbHelper = new DataBaseHelper(mContext);
try
myDbHelper.createDataBase();
catch (IOException ioe)
throw new Error("Unable to create database");
try myDbHelper.openDataBase();
catch (SQLException sqle) sqle.printStackTrace();
String rr=worldpopulationlist.get(position).getprimaryid();
db = myDbHelper.getWritableDatabase();
switch (worldpopulationlist.get(position).getfavoir())
case 0:
mCursor= db.rawQuery("UPDATE khotbe SET favorites = 1 WHERE my_id ="+rr+" ;",null);
mCursor.moveToFirst();
holder.btn.setBackgroundResource(R.drawable.star);
Toast.makeText(mContext, "به لیست علاقه مندی ها اضافه شد", Toast.LENGTH_SHORT).show();
break;
case 1:
mCursor= db.rawQuery("UPDATE khotbe SET favorites = 0 WHERE my_id ="+rr+" ;",null);
mCursor.moveToFirst();
holder.btn.setBackgroundResource(R.drawable.ic_launcher);
Toast.makeText(mContext, "از لیست علاقه مندی های حذف گردید", Toast.LENGTH_SHORT).show();
break;
default:
break;
);
和类myitems
public class myitems
private String title;
private String field_translation_id;
private String shomare;
private String primaryid;
private int favorit;
public myitems(String title,String field_translation_id,String shomare,String primaryid,int favorit)
this.title=title;
this.field_translation_id=field_translation_id;
this.shomare=shomare;
this.primaryid=primaryid;
this.favorit=favorit;
public String gettitle()
return this.title;
public String get_field_translation_id()
return this.field_translation_id;
public String getshomare()
return this.shomare;
public String getprimaryid()
return this.primaryid;
public int getfavoir()
return this.favorit;
和 MainActivity
public class towkhotbe extends ActionBarActivity
DataBaseHelper myDbHelper;
ListView mylist;
ArrayList<String> iran,arr_intityid,arrshomare,primarykeyarrlist;
String[] fa,mysid,myshomare,primarykeyarr;
SQLiteDatabase db;
Cursor mCursor;
int translate;
EditText mysearch;
int [] favorit;
ArrayList<Integer> favor;
ListViewAdapter adapter;
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
@SuppressWarnings("deprecation")
private ActionBarDrawerToggle mDrawerToggle;
private CharSequence mDrawerTitle;
private CharSequence mTitle;
android.support.v7.app.ActionBar actionbar;
private ArrayList<NavDrawerItem> navDrawerItems;
private NavDrawerListAdapter sadapter;
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState)
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.tow_khotbe);
Intent myintent=getIntent();
translate=myintent.getExtras().getInt("translate");
mylist=(ListView)findViewById(R.id.mylist);
mysearch=(EditText)findViewById(R.id.edtxtsearch);
iran=new ArrayList<String>();
arr_intityid=new ArrayList<String>();
arrshomare=new ArrayList<String>();
primarykeyarrlist=new ArrayList<String>();
favor=new ArrayList<Integer>();
@Override
protected void onResume()
// TODO Auto-generated method stub
super.onResume();
myDbHelper = new DataBaseHelper(this.getApplicationContext());
myDbHelper = new DataBaseHelper(this);
try
myDbHelper.createDataBase();
// contentLog.append("Database Created\n");
catch (IOException ioe)
throw new Error("Unable to create database");
try
myDbHelper.openDataBase();
catch (SQLException sqle)
sqle.printStackTrace();
ArrayList<myitems> arraylist = new ArrayList<myitems>();
db = myDbHelper.getReadableDatabase();
mCursor= db.rawQuery("SELECT field_translation_id_value,title,translate,my_id,favorites FROM khotbe"
+ " WHERE translate ="+translate+" ORDER BY field_translation_id_value ASC ;",null);
int i = 1;
mCursor.moveToFirst();
while (mCursor.isAfterLast() == false)
// contentLog.append("(" + i++ + ")\t\t" + mCursor.getString(1) + "\n");
iran.add(mCursor.getString(1));
arr_intityid.add(mCursor.getString(0));
primarykeyarrlist.add(mCursor.getString(3));
favor.add(mCursor.getInt(4));
arrshomare.add(""+i++);
mCursor.moveToNext();
fa= new String [iran.size()];
fa=iran.toArray(fa);
mysid= new String [arr_intityid.size()];
mysid=arr_intityid.toArray(mysid);
primarykeyarr= new String [primarykeyarrlist.size()];
primarykeyarr=primarykeyarrlist.toArray(primarykeyarr);
myshomare=new String[arrshomare.size()];
myshomare=arrshomare.toArray(myshomare);
favorit =new int[favor.size()];
for (int t= 0; t < favor.size(); t++)
favorit[t]=favor.get(t).intValue();
mCursor.moveToPosition(0);
for (int j = 0; j < fa.length; j++)
myitems qqq= new myitems(fa[j],mysid[j],myshomare[j],primarykeyarr[j],favorit[j]);
arraylist.add(qqq);
adapter=new ListViewAdapter(this, arraylist);
mylist.setAdapter(adapter);
Button btn=(Button)findViewById(R.id.btnfavor);
btn.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View v)
Toast.makeText(towkhotbe.this, "11111111", Toast.LENGTH_SHORT).show();
);
【问题讨论】：
使用 notifyDatasetChanged 方法 @Nilesh 可以进一步解释一下 【参考方案1】：在您喜欢的按钮的onClick() 中使用adapter.notifyDataSetChanged();
示例
Button favoriteButton = (Button) findViewById(R.id.bFavButton);
favoriteButton.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View view)
//Add or remove items to list
..............
//Hey, adapter! Data set updated!
adapter.notifyDataSetChanged();
);
【讨论】：
@Shifar Shifz 如何将 MainActivity 中的适配器放入 ListViewAdapter？ 您可以在Activity 的方法之外声明ListViewAdapter，并且可以从类的任何位置调用。您必须阅读此luan-itworld.blogspot.in/2013/08/…
@ Shifar Shifz 当我在 MainActivity 中使用 onclick 时，应用程序无法运行，但在 ListViewAdapter 中的 onclick 可以。为什么？
我认为您在按钮的onClick() 中犯了一些错误。发布您的完整活动。
@Shifar Shifz 我要更改 MainActiviyt 请再看一遍以上是关于单击收藏夹按钮时更新列表视图的主要内容，如果未能解决你的问题，请参考以下文章