将所有值从自定义列表视图（包括EditText）保存到SQLite中

问题描述 投票：0回答：1

我希望将数据从列表视图上的View值存储到SQLite，并在重新打开应用程序时在列表视图上流行它们。我在EditText上使用了此方法

 ....setOnFocusChangeListener(new View.OnFocusChangeListener() {
 public void onFocusChange(View v, boolean hasFocus) {...

在更改EditText之后立即在SQLite上保存数据，但是它无法正常工作。enter image description here这里是MyCustomAdapter类

  public class MyCustomAdapter extends ArrayAdapter<Song> {
  private Context context;
  private int resource;
  private ArrayList<Song> listsong;
  private DatabaseHelper datab;
  private final String TAG = getClass().getSimpleName();
  public MyCustomAdapter(Context context, int resource, ArrayList<Song> objects) {
    super(context, resource, objects);
    this.context=context;
    this.resource=resource;
    this.listsong=objects;
}
@Override
public Song getItem(int position) {
    return listsong.get(position);
}
@NonNull
@Override
public View getView(final int position, View convertView, ViewGroup parent) {

    ViewHolder viewHolder;
    viewHolder=null;
    if(convertView==null){
        convertView = LayoutInflater.from(context).inflate(R.layout.song_items,parent,false);

        viewHolder = new ViewHolder();

        viewHolder.tenbai = (TextView) convertView.findViewById(R.id.text);
        viewHolder.delaytime = (EditText) convertView.findViewById(R.id.delay);
        viewHolder.timeunit = (TextView) convertView.findViewById(R.id.timeunit);
        //attach the TextWatcher listener to the EditText


        convertView.setTag(viewHolder);
        Log.d(TAG, "getView: "+(position+1));
        // SELETECTED

    }
    else {
        viewHolder = (ViewHolder) convertView.getTag();
    }

    Song infor = listsong.get(position);
    viewHolder.tenbai.setText(infor.getTenbai());
    viewHolder.timeunit.setText(infor.getTimeunit());
    viewHolder.delaytime.setVisibility(View.VISIBLE);


 //Fill EditText with the value you have in data source
    viewHolder.delaytime.setText(infor.getDelaytime());
    viewHolder.delaytime.setId(position);

 //we need to update adapter once we finish with editing
    viewHolder.delaytime.setOnFocusChangeListener(new 
 View.OnFocusChangeListener() {

        public void onFocusChange(View v, boolean hasFocus) {

            if (!hasFocus) {
                final int position = v.getId();
                final EditText Caption = (EditText) v;
                listsong.get(position).setDelaytime(Caption.getText().toString());

                new DatabaseHelper(context).insertSong( listsong.get(position) );
            }

        }

    });

    return convertView;
}
public class ViewHolder{
    TextView tenbai;
    EditText delaytime;
    TextView timeunit;

}
}

这里是DatabaseHelper类

public class DatabaseHelper extends SQLiteOpenHelper {

// Database Version
private static final int DATABASE_VERSION = 1;

// Database Name
private static final String DATABASE_NAME = "songs_db";


public DatabaseHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {

    // create notes table
    db.execSQL(Song.CREATE_TABLE);
}

// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // Drop older table if existed
    db.execSQL("DROP TABLE IF EXISTS " + Song.TABLE_NAME);

    // Create tables again
    onCreate(db);
}

public boolean ifExists(String tenbai)
{    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = null;
    String checkQuery = "SELECT " + Song.COLUMN_TENBAI + " FROM " + Song.TABLE_NAME + " WHERE " + Song.COLUMN_TENBAI + "= '"+tenbai + "'";
    cursor= db.rawQuery(checkQuery,null);
    boolean exists = (cursor.getCount() > 0);
    cursor.close();
    return exists;
}
public boolean isEmpty(String TableName){

    SQLiteDatabase database = this.getReadableDatabase();
    int NoOfRows = (int) DatabaseUtils.queryNumEntries(database,TableName);

    if (NoOfRows == 0){
        return true;
    }else {
        return false;
    }
}

public boolean isTableExists(String tableName) {
    SQLiteDatabase db = this.getWritableDatabase();
    boolean isExist = false;
    Cursor cursor = db.rawQuery("select DISTINCT tbl_name from sqlite_master where tbl_name = '" + tableName + "'", null);
    if (cursor != null) {
        if (cursor.getCount() > 0) {
            isExist = true;
        }
        cursor.close();
    }
    return isExist;
}

public void insertSong(Song song) {
    // get writable database as we want to write data
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues values = new ContentValues();
    values.put(Song.COLUMN_TENBAI, song.getTenbai());
    values.put(Song.COLUMN_DUONGDAN, song.getDuongdan());
    values.put(Song.COLUMN_DELAYTIME, song.getDelaytime());
    values.put(Song.COLUMN_TIMEUNIT, song.getTimeunit());
    // insert row
    long id = db.insert(Song.TABLE_NAME, null, values);

    // close db connection
    db.close();
    Log.d("Ket qua", "addStudent Successfuly");
    // return newly inserted row id

}

// TAO MANG CHO RECYCLE QUAN NotesAdapter
public List<Song> getAllSongs() {
    List<Song> notes = new ArrayList<>();

    // Select All Query
    String selectQuery = "SELECT  * FROM " + Song.TABLE_NAME + " ORDER BY " +
            Song.COLUMN_TENBAI + " DESC";

    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (cursor.moveToFirst()) {
        do {
            Song song = new Song();
            song.setId(cursor.getInt(cursor.getColumnIndex(song.COLUMN_ID)));
            song.setTenbai(cursor.getString(cursor.getColumnIndex(song.COLUMN_TENBAI)));
            song.setDuongdan(cursor.getString(cursor.getColumnIndex(song.COLUMN_DUONGDAN)));
            song.setDelaytime(cursor.getString(cursor.getColumnIndex(song.COLUMN_DELAYTIME)));
            song.setTimeunit(cursor.getString(cursor.getColumnIndex(song.COLUMN_TIMEUNIT)));

            notes.add(song);
        } while (cursor.moveToNext());
    }

    // close db connection
    db.close();

    // return notes list
    return notes;
}


public int getNotesCount() {
    String countQuery = "SELECT  * FROM " + Song.TABLE_NAME;
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery(countQuery, null);

    int count = cursor.getCount();
    cursor.close();


    // return count
    return count;
}
public int updatedelaytime(Song song) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues values = new ContentValues();
    values.put(Song.COLUMN_DELAYTIME, song.getDelaytime());
    // updating row
    return db.update(Song.TABLE_NAME, values, Song.COLUMN_TENBAI + " = ?",new String[]{String.valueOf(song.getTenbai())});
}

这里是MainActivity类

public class MainActivity extends AppCompatActivity {
ImageButton btnList,btnPlay,btnStop,btnForward,btnPrev;
Button btnsave;
private MediaPlayer mp;
private TextView txtTotal,txtCurrent;

 private SeekBar soundSeek;

int currentPosition = 0;
int totalDuration = 0;
int value  =0;
boolean Playing = false;
String audioFile = "";
int SONG_NUMBER = 0;
int CURRENT_NUMBER= 0;
private DatabaseHelper db;
private ListView playList;
MyCustomAdapter myCustomAdapter;
public static ArrayList<Song> fileNames;
public ArrayList<Song> newlistsong;

String INTERNAL_PATH = Environment.getExternalStorageDirectory() .toString()+"/";;
String EXTERNAL_PATH = "Download";

static String AUDIO_PATH = "";

String[] DIRECTORIES = {INTERNAL_PATH,EXTERNAL_PATH};
public static int songNumber ;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate( savedInstanceState );
    setContentView( R.layout.activity_main );

    btnsave = (Button) findViewById(R.id.btn_save);
    btnList = (ImageButton)findViewById(R.id.imbList);
    btnPlay = (ImageButton) findViewById(R.id.imageButton3);
    btnStop = (ImageButton) findViewById(R.id.imageButton4);
    btnForward = (ImageButton) findViewById(R.id.imageButton5);
    btnPrev = (ImageButton) findViewById(R.id.imageButton2);

    txtCurrent = (TextView) findViewById(R.id.textView2);
    txtTotal = (TextView) findViewById(R.id.textView);
    soundSeek = (SeekBar) findViewById(R.id.seekBar);

    mp = new MediaPlayer();
    playList = (ListView)findViewById(R.id.listView);
    playList.setItemsCanFocus( true );

    db = new DatabaseHelper(this);

 if(!db.isTableExists( "songs" )||db.isEmpty("songs")) {
     fileNames=new ArrayList<Song>(  );
     Collections.sort(fileNames, new Comparator<Song>() {
         @Override
         public int compare(Song data1, Song data2) {
     return (int) data1.getTenbai().charAt(0) - (int) data2.getTenbai().charAt(0);
         }

     });
     getFiles();
     playList.setAdapter(new MyCustomAdapter( this, R.layout.song_items, fileNames ) );
 }
 else
    {
        newlistsong =new ArrayList<Song>(  );
        Collections.sort(newlistsong, new Comparator<Song>() {
            @Override
            public int compare(Song data1, Song data2) {
                return (int) data1.getTenbai().charAt(0) - (int) data2.getTenbai().charAt(0);
            }
        });
        newlistsong.addAll( db.getAllSongs() );
        playList.setAdapter( new MyCustomAdapter( this, R.layout.song_items, newlistsong ));
        System.out.println( "mang : " +newlistsong.size()+"phan tu: "+newlistsong.toString());
    }

    playList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
            Toast.makeText(MainActivity.this, fileNames.get(position).getDuongdan().toString()+" vi tri "+ position, Toast.LENGTH_LONG).show();

            SONG_NUMBER=position;
           playMedia(fileNames.get(position).getDuongdan().toString());
        }
    });

    setListeners();
}



public void getFiles(){
    fileNames.clear();
    for(int d = 0 ; d < DIRECTORIES.length ; d++){
        File f = new File(DIRECTORIES[d]);
        f.mkdir();

        File[] files = f.listFiles();

        if(files != null && files.length > 0){
            for(File file : files){
                if(file.isDirectory()){
                    scanDirectory(file);
                }else{
                    addSong(file);
                }
            }
        }
    }

}

public void scanDirectory(File directory){
    if(directory != null){
        File[] listFiles = directory.listFiles();

        for (File file:listFiles){
            // neu muon load tat ca cac file trong folder cha
            if(file.isDirectory()){
                scanDirectory(file);
            }else{
                addSong(file);
            }

        }

    }
}

    public void addSong(File song) {

    if (song.getName().endsWith( ".mp3" ) && song.getAbsolutePath().contains( EXTERNAL_PATH )) {
        fileNames.add( new Song( song.getName(), song.getAbsolutePath(), "", "sec" ) );
    }
}
    public static String getpath(String tenbai)
    { String path = null;
        for (int i=0;i<fileNames.size();i++)
        {
            if(fileNames.get(i).getTenbai().equals( tenbai ))
            {path= fileNames.get(i).getDuongdan();}
        }
        return path;
    }

public void save()
{
            DatabaseHelper dbhelp=  new DatabaseHelper(this);
    for(int i=0;i<fileNames.size();i++) {
        Song moderntalking= new Song();
        moderntalking.setTenbai( fileNames.get(i).getTenbai());
        moderntalking.setDuongdan( fileNames.get(i).getDuongdan());
        moderntalking.setDelaytime( fileNames.get(i).getDelaytime());
        moderntalking.setTimeunit( fileNames.get(i).getTimeunit());
        System.out.println( moderntalking.getDelaytime() );
        if(!dbhelp.ifExists( moderntalking.getTenbai() ))
        {  dbhelp.insertSong( fileNames.get(i) );}
        else
        {  dbhelp.updatedelaytime( moderntalking );}
    }

    Toast.makeText(MainActivity.this, "saved",Toast.LENGTH_LONG).show();
}
}

[这里是歌曲班公开课歌曲{

public static final String TABLE_NAME = "songs";

public static final String COLUMN_ID = "id";
public static final String COLUMN_TENBAI = "tenbai";
public static final String COLUMN_DUONGDAN = "duongdan";
public static final String COLUMN_DELAYTIME = "delaytime";
public static final String COLUMN_TIMEUNIT = "timeunit";

    public  Integer id;
    public String tenbai;
    public String duongdan;
    public String delaytime;
    public String timeunit;

public static final String CREATE_TABLE =
        "CREATE TABLE " + TABLE_NAME + "("
                + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
                + COLUMN_TENBAI + " TEXT,"
                + COLUMN_DUONGDAN + " TEXT,"
                + COLUMN_DELAYTIME + " TEXT,"
                + COLUMN_TIMEUNIT + " TEXT"
                + ")";

public Song() {}
public Song( String tenbai, String duongdan, String delaytime, String timeunit) {
    this.tenbai = tenbai;
    this.duongdan = duongdan;
    this.delaytime = delaytime;
    this.timeunit = timeunit;
}
public Song(Integer id, String tenbai, String duongdan, String delaytime, String timeunit) {
    this.id = id;
    this.tenbai = tenbai;
    this.duongdan = duongdan;
    this.delaytime = delaytime;
    this.timeunit = timeunit;
}

public Integer getId() {
    return id;
}

public void setId(Integer id) {
    this.id = id;
}

public String getTenbai() {
    return tenbai;
}

public void setTenbai(String tenbai) {
    this.tenbai = tenbai;
}

public String getDuongdan() {
    return duongdan;
}

public void setDuongdan(String duongdan) {
    this.duongdan = duongdan;
}

public String getDelaytime() {
    return delaytime;
}

public void setDelaytime(String delaytime) {
    this.delaytime = delaytime;
}

public String getTimeunit() {
    return timeunit;
}

public void setTimeunit(String timeunit) {
    this.timeunit = timeunit;
}
}

我想在SQLite中存储字符串名称，路径，延迟时间，时间单位。然后让它们正确显示在Customized Listview上。感谢您的帮助

android android-studio android-listview android-sqlite android-adapter
1个回答
0
投票

可能取决于用户实际执行的操作，焦点可能不会改变。

例如

[当用户首先单击edittext时，焦点可能已经在此上。

并且如果应用关闭，焦点可能仍然位于第一个edittext

因此不会触发任何事件

确实有两种方法可以正确地实现此目标：-

1]在TextWatcher上添加https://developer.android.com/reference/android/text/TextWatcher.html edittext，因此，如果在edittext中更改了值，则会触发TextWatcher，并将该值保存到数据库中。

edittext文档https://developer.android.com/reference/android/widget/EditText的引用>

您还可以在用户通过将TextWatcher添加到编辑文本来更改文本时接收回调。例如，当您要在进行更改时添加自动保存功能或验证用户输入的格式时，此功能很有用。您可以使用TextView＃addTextChangedListener方法添加文本观察器。

2）使用应用程序的onPause方法处理将值保存到数据库的过程，因此，当应用程序被关闭或置于后台时，代码将查看所有列表框项目并确定哪些项目需要在数据库中更新。

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