未在新活动中显示ListView
我正在尝试使ListView出现在新活动中。我可以在logcat中看到记录ID，并且可以看到在调试视图中选择了正确的ID，但是当我转到新活动时，列表数组为空。
这是我在调试视图中看到的：
在 logcat 中，我看到了以下内容：
2018-10-07 11:39:09.286 12624-12624/ca.rvogl.tpbcui D/SAVEDLEAGUEID_VAL: 1
2018-10-07 11:39:09.286 12624-12624/ca.rvogl.tpbcui D/LEAGUEID_VAL: android.support.v7.widget.AppCompatTextView{e67a170 G.ED..... ......I. 0,0-0,0 #7f080112 app:id/tvLeagueId}
2018-10-07 11:39:09.293 12624-12624/ca.rvogl.tpbcui D/GETALLBOWLERS-SQL: SQL used = >>>>SELECT * FROM bowlers WHERE league_id = '1' ORDER BY timestamp DESC<<<<
2018-10-07 11:39:09.298 12624-12624/ca.rvogl.tpbcui D/GETALLBOWLERS-CNT: Number of rows retrieved = 0
2018-10-07 11:39:09.299 12624-12624/ca.rvogl.tpbcui D/GETALLBOWLERS-CNT: Number of elements in bowlerslist = 0
正如您从日志猫中看到的那样，已保存的LeagueId将传递到SQLite查询，该SQLite查询假定正在获取listview的Bowler列表。但是，常礼帽列表中的元素数为0。
我已经一遍遍地遍历代码，但是我无法找出问题所在。
LeagueAdapter.java
public class LeagueAdapter extends RecyclerView.Adapter<LeagueAdapter.MyViewHolder> {
private Context context;
private List<League> leaguesList;
public void notifyDatasetChanged(List<League> newleagueslist) {
leaguesList.clear();
leaguesList.addAll(newleagueslist);
super.notifyDataSetChanged();
}
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView name;
public TextView basescore;
public TextView basescorepercentage;
public TextView id;
public TextView wins;
public TextView losses;
public TextView timestamp;
public TextView buttonViewOption;
public MyViewHolder(View view) {
super(view);
id = view.findViewById( R.id.tvLeagueId);
name = view.findViewById(R.id.tvSeriesName );
basescore = view.findViewById(R.id.tvBaseScore );
basescorepercentage = view.findViewById(R.id.tvBaseScorePercentage );
wins = view.findViewById(R.id.tvLeagueWins );
losses = view.findViewById(R.id.tvLeagueLosses );
timestamp = view.findViewById(R.id.timestamp);
buttonViewOption = (TextView) view.findViewById(R.id.buttonViewOptions);
}
}
public LeagueAdapter(Context context, List<League> leaguesList) {
this.context = context;
this.leaguesList = leaguesList;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.listview_league, parent, false);
return new MyViewHolder(itemView);
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
League league = leaguesList.get(position);
int id = league.getId();
Log.d("id", String.valueOf(id));
int leagueId = id;
Log.d("leagueId", String.valueOf(leagueId));
holder.id.setText(String.valueOf(leagueId));
holder.name.setText(league.getName());
holder.basescore.setText(league.getBaseScore());
holder.basescorepercentage.setText(league.getBaseScorePercentage());
holder.wins.setText(league.getWins());
holder.losses.setText(league.getLosses());
/*if (league.getAverage() != "") {
holder.leagueAverage.setText(String.format("League Avg: %s", league.getAverage()));
} else {
holder.leagueAverage.setText(String.format("League Avg: %s", "0"));
}*/
//Formatting And Displaying Timestamp
holder.timestamp.setText(formatDate(league.getTimestamp()));
holder.buttonViewOption.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//creating a popup menu
PopupMenu popup = new PopupMenu(context, holder.buttonViewOption);
//inflating menu from xml resource
popup.inflate(R.menu.league_options_menu);
//adding click listener
popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
@Override
public boolean onMenuItemClick(MenuItem item) {
switch (item.getItemId()) {
case R.id.profile:
Log.d("leagueId", String.valueOf(position));
int leagueId = league.getId();
String savedLeagueId = String.valueOf(id);
Intent myIntent = new Intent(context, LeagueProfileViewActivity.class);
myIntent.putExtra("leagueId", leagueId);
context.startActivity(myIntent);
break;
case R.id.delete:
((MainActivity) context).deleteLeague(position);
break;
}
return false;
}
});
//displaying the popup
popup.show();
}
});
holder.name.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//String leagueId = String.valueOf(leaguesList.get(position).getId());
int leagueId = league.getId();
String savedLeagueId = String.valueOf(id);
Log.d("leagueId", String.valueOf(position));
Intent myIntent = new Intent(context, BowlerActivity.class);
myIntent.putExtra("leagueId", savedLeagueId);
context.startActivity(myIntent);
}
});
}
@Override
public int getItemCount() {
return leaguesList.size();
}
//Formatting TimeStamp to 'EEE MMM dd yyyy (HH:mm:ss)'
//Input : 2018-05-23 9:59:01
//Output : Wed May 23 2018 (9:59:01)
private String formatDate(String dateStr) {
try {
SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date date = fmt.parse(dateStr);
SimpleDateFormat fmtOut = new SimpleDateFormat("EEE MMM dd yyyy (HH:mm:ss)");
return fmtOut.format(date);
} catch (ParseException e) {
}
return "";
}
}
我要使用holder.name转到BowlerActivity，在这里我要使用意图传递联赛ID。
BowlerActivity.java
public class BowlerActivity extends AppCompatActivity {
private BowlerAdapter mAdapter;
private final List<Bowler> bowlersList = new ArrayList<>();
private TextView noBowlersView;
private DatabaseHelper db;
private TextView leagueId;
private String savedLeagueId;
/*private TextView seriesleagueId;
private String seriesLeagueId;
private TextView bowlerAverage;
private TextView bowlerHandicap;
private String savedBowlerAverage;*/
private static final String PREFS_NAME = "prefs";
private static final String PREF_BLUE_THEME = "blue_theme";
private static final String PREF_GREEN_THEME = "green_theme";
private static final String PREF_ORANGE_THEME = "purple_theme";
private static final String PREF_RED_THEME = "red_theme";
private static final String PREF_YELLOW_THEME = "yellow_theme";
@Override protected void onResume() {
super.onResume();
db = new DatabaseHelper( this );
mAdapter.notifyDatasetChanged( db.getAllBowlers(savedLeagueId ) );
}
@Override
protected void onCreate(Bundle savedInstanceState) {
//Use Chosen Theme
SharedPreferences preferences = getSharedPreferences( PREFS_NAME, MODE_PRIVATE );
boolean useBlueTheme = preferences.getBoolean( PREF_BLUE_THEME, false );
if (useBlueTheme) {
setTheme( R.style.AppTheme_Blue_NoActionBar );
}
boolean useGreenTheme = preferences.getBoolean( PREF_GREEN_THEME, false );
if (useGreenTheme) {
setTheme( R.style.AppTheme_Green_NoActionBar );
}
boolean useOrangeTheme = preferences.getBoolean( PREF_ORANGE_THEME, false );
if (useOrangeTheme) {
setTheme( R.style.AppTheme_Orange_NoActionBar );
}
boolean useRedTheme = preferences.getBoolean( PREF_RED_THEME, false );
if (useRedTheme) {
setTheme( R.style.AppTheme_Red_NoActionBar );
}
boolean useYellowTheme = preferences.getBoolean( PREF_YELLOW_THEME, false );
if (useYellowTheme) {
setTheme( R.style.AppTheme_Yellow_NoActionBar );
}
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bowler);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
Objects.requireNonNull( getSupportActionBar() ).setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startActivity(new Intent(getApplicationContext(),MainActivity.class));
finish();
overridePendingTransition(0, 0);
}
});
savedLeagueId = String.valueOf(getIntent().getStringExtra("leagueId"));
leagueId = findViewById(R.id.tvLeagueId);
Log.d("SAVEDLEAGUEID_VAL", String.valueOf(savedLeagueId));
Log.d("LEAGUEID_VAL", String.valueOf(leagueId));
/*bowlerAverage = (TextView) findViewById(R.id.tvBowlerAverage);
bowlerHandicap = (TextView) findViewById(R.id.tvBowlerHandicap);*/
CoordinatorLayout coordinatorLayout = findViewById( R.id.coordinator_layout );
RecyclerView recyclerView = findViewById( R.id.recycler_view );
noBowlersView = findViewById(R.id.empty_bowlers_view);
db = new DatabaseHelper(this);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.add_bowler_fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//showBowlerDialog(false, null, -1);
boolean shouldUpdate = false;
int bowlerId = -1;
String leagueId = String.valueOf(savedLeagueId);
Intent intent = new Intent(getApplicationContext(), BowlerProfileEditActivity.class);
intent.putExtra("shouldUpdate", shouldUpdate);
intent.putExtra("leagueId", leagueId);
intent.putExtra("bowlerId", bowlerId);
startActivity(intent);
finish();
overridePendingTransition(0, 0);
}
});
mAdapter = new BowlerAdapter(this, bowlersList);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(mAdapter);
toggleEmptyBowlers();
}
//Inserting New Bowler In The Database And Refreshing The List
private void createBowler(String leagueId, String bowlerName) {
String bowlerAverage = "0";
//Inserting Bowler In The Database And Getting Newly Inserted Bowler Id
long id = db.insertBowler(savedLeagueId, bowlerName, bowlerAverage);
//Get The Newly Inserted Bowler From The Database
Bowler n = db.getBowler(savedLeagueId);
if (n != null) {
//Adding New Bowler To The Array List At Position 0
bowlersList.add( 0, n );
//Refreshing The List
mAdapter.notifyDatasetChanged(db.getAllBowlers(savedLeagueId));
//mAdapter.notifyDataSetChanged();
toggleEmptyBowlers();
}
}
//Updating Bowler In The Database And Updating The Item In The List By Its Position
private void updateBowler(String bowlerName, int position) {
Bowler n = bowlersList.get(position);
//Updating Bowler Text
n.setLeagueId(savedLeagueId);
n.setName(bowlerName);
//Updating The Bowler In The Database
db.updateBowler(n);
//Refreshing The List
bowlersList.set(position, n);
mAdapter.notifyItemChanged(position);
toggleEmptyBowlers();
}
//Deleting Bowler From SQLite Database And Removing The Bowler Item From The List By Its Position
public void deleteBowler(int position) {
Snackbar snackbar = Snackbar.make(findViewById(android.R.id.content), "Series will be deleted.", Snackbar.LENGTH_LONG)
.setActionTextColor(Color.YELLOW)
.setAction("OK", new View.OnClickListener() {
@Override
public void onClick(View v) {
//Deleting The Bowler From The Database
db.deleteBowler(bowlersList.get(position));
//Removing The Bowler From The List
bowlersList.remove(position);
mAdapter.notifyItemRemoved(position);
//db.leagueAverageScore(savedLeagueId);
toggleEmptyBowlers();
}
});
snackbar.show();
}
//Toggling List And Empty Bowler View
private void toggleEmptyBowlers() {
//You Can Check bowlerList.size() > 0
if (db.getBowlersCount() > 0) {
noBowlersView.setVisibility( View.GONE);
} else {
noBowlersView.setVisibility( View.VISIBLE);
}
}
@Override
public void onRestart() {
super.onRestart();
//When BACK BUTTON is pressed, the activity on the stack is restarted
//Do what you want on the refresh procedure here
}
@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) {
Intent intent = new Intent(this, SettingsActivity.class);
startActivity(intent);
overridePendingTransition(0, 0);
return true;
}
return super.onOptionsItemSelected( item );
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
//Check If Request Code Is The Same As What Is Passed - Here It Is 1
if(requestCode==1)
{
String savedLeagueId=data.getStringExtra("seriesLeagueId");
String seriesBowlerId=data.getStringExtra("seriesBowlerId");
bowlersList.addAll(db.getAllBowlers(savedLeagueId));
}
}
@Override
public void onBackPressed() {
startActivity(new Intent(getApplicationContext(),MainActivity.class));
finish();
overridePendingTransition(0, 0);
}
}
Bowler 方法
public long insertBowler(String leagueId, String bowlerName, String bowlerAverage) {
String bowlerHandicap ="0";
//Get Writable Database That We Want To Write Data Too
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
//`id` and `timestamp` Will Be Inserted Automatically
values.put(Bowler.COLUMN_LEAGUE_ID, leagueId);
values.put(Bowler.COLUMN_NAME, bowlerName);
values.put(Bowler.COLUMN_BOWLER_AVERAGE, bowlerAverage);
values.put(Bowler.COLUMN_BOWLER_HANDICAP, bowlerHandicap);
//Insert Row
//long id = db.insert(Bowler.TABLE_NAME, null, values);
long id = db.insertOrThrow( Bowler.TABLE_NAME, null, values );
Log.d("INSERTBOWLER","Number of bowlers in db = " + String.valueOf( DatabaseUtils.queryNumEntries(db,Bowler.TABLE_NAME)));
//Close Database Connection
db.close();
//Return Newly Inserted Row Id
return id;
}
public Bowler getBowler(String leagueId) {
//Get Readable Database If We Are Not Inserting Anything
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query( Bowler.TABLE_NAME,
new String[]{Bowler.COLUMN_ID, Bowler.COLUMN_LEAGUE_ID, Bowler.COLUMN_NAME, Bowler.COLUMN_BOWLER_AVERAGE, Bowler.COLUMN_BOWLER_HANDICAP, Bowler.COLUMN_TIMESTAMP},
Bowler.COLUMN_LEAGUE_ID + "=?",
new String[]{String.valueOf(leagueId)}, null, null, null, null);
Bowler bowler = null;
if (cursor.moveToFirst()) {
//Prepare Bowler Object
bowler = new Bowler(
cursor.getInt(cursor.getColumnIndex(Bowler.COLUMN_ID)),
cursor.getString(cursor.getColumnIndex(Bowler.COLUMN_LEAGUE_ID)),
cursor.getString(cursor.getColumnIndex(Bowler.COLUMN_NAME)),
cursor.getString(cursor.getColumnIndex(Bowler.COLUMN_BOWLER_AVERAGE)),
cursor.getString(cursor.getColumnIndex(Bowler.COLUMN_BOWLER_HANDICAP)),
cursor.getString(cursor.getColumnIndex(Bowler.COLUMN_TIMESTAMP)));
//Close Database Connection
cursor.close();
return bowler;
} else {
return bowler;
}
}
public List<Bowler> getAllBowlers(String leagueId) {
List<Bowler> bowlers = new ArrayList<>();
//Select All Query
String selectQuery = "SELECT * FROM " + Bowler.TABLE_NAME + " WHERE " + Bowler.COLUMN_LEAGUE_ID + " = '" + leagueId + "'" + " ORDER BY " +
Bowler.COLUMN_TIMESTAMP + " DESC";
Log.d("GETALLBOWLERS-SQL","SQL used = >>>>" +selectQuery + "<<<<");
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
Log.d("GETALLBOWLERS-CNT","Number of rows retrieved = " + String.valueOf(cursor.getCount()));
//Looping Through All Rows And Adding To The List
if (cursor.moveToFirst()) {
do {
Bowler bowler = new Bowler();
bowler.setId(cursor.getInt(cursor.getColumnIndex(Bowler.COLUMN_ID)));
bowler.setLeagueId(cursor.getString(cursor.getColumnIndex(Bowler.COLUMN_LEAGUE_ID)));
bowler.setName(cursor.getString(cursor.getColumnIndex(Bowler.COLUMN_NAME)));
bowler.setAverage(cursor.getString(cursor.getColumnIndex(Bowler.COLUMN_BOWLER_AVERAGE)));
bowler.setHandicap(cursor.getString(cursor.getColumnIndex(Bowler.COLUMN_BOWLER_HANDICAP)));
bowler.setTimestamp(cursor.getString(cursor.getColumnIndex(Bowler.COLUMN_TIMESTAMP)));
bowlers.add(bowler);
} while (cursor.moveToNext());
}
cursor.close();
//Close Database Connection
db.close();
Log.d("GETALLBOWLERS-CNT","Number of elements in bowlerslist = " + String.valueOf(bowlers.size()));
//Return Bowlers List
return bowlers;
}
public int getBowlersCount() {
String countQuery = "SELECT * FROM " + Bowler.TABLE_NAME;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int count = cursor.getCount();
cursor.close();
//Return The Count
return count;
}
public int updateBowler(Bowler bowler) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(Bowler.COLUMN_LEAGUE_ID, bowler.getLeagueId());
values.put(Bowler.COLUMN_NAME, bowler.getName());
values.put(Bowler.COLUMN_BOWLER_AVERAGE, bowler.getAverage());
//Updating Row
return db.update(Bowler.TABLE_NAME, values, Bowler.COLUMN_ID + " = ?",
new String[]{String.valueOf(bowler.getId())});
}
public void deleteBowler(Bowler bowler) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete( Bowler.TABLE_NAME, Bowler.COLUMN_ID + " = ?",
new String[]{String.valueOf( bowler.getId())});
db.close();
}
我希望有人能够指出我在做什么，以解决此问题。
如果需要任何其他信息，请告诉我，我将其发布。
1 个答案:
答案 0 :(得分：0)
我已经弄清楚了为什么所有新的常礼帽条目都具有 2 的ID。在我的Bowler Profile Activity编辑中，我具有以下内容：leagueId = String.valueOf(getIntent().getIntExtra("leagueId",2));默认值为2，并且由于我没有以正确的方式获取传递给新Activity的信息，因此该应用始终使用 2 作为BowlerId。
我将捕获信息的代码从意图更改为以下代码：
Intent intent = getIntent();
leagueId = intent.getStringExtra("leagueId");
通过这次更改，我得以捕获属于特定联赛的所有保龄球选手。在阅读了以下文章之后，我才意识到我错误地传递了信息：
Pass a String from one Activity to another Activity in Android
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