Question

我正在尝试在Android中制作笔记/日记录入应用程序。我希望更新条目时数据库应占用系统时间，然后将其添加到列表视图中。

list_personal.xml ＆LT;

?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:padding="10dp"
        >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            android:weightSum="10"
            >

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="9"
                android:textAppearance="?android:attr/textAppearanceLarge"
                android:text="1."
                android:id="@+id/index_personal"/>

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:textAppearance="?android:attr/textAppearanceLarge"
                android:text="Title"
                android:id="@+id/title_personal"/>

        </LinearLayout>

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textAppearance="?android:textAppearanceMedium"
            android:layout_marginTop="5dp"
            android:text="Description"
            android:id="@+id/description_personal"/>
    </LinearLayout>

</LinearLayout>

DatabaseHandler_personal.class

 package dbms.vit.myapplication;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import java.util.ArrayList;
import java.util.List;

public class DatabaseHandler_personal extends SQLiteOpenHelper {

public DatabaseHandler_personal(Context context) {
    super(context, DatabaseValues_personal.DATABASE_NAME, null, DatabaseValues_personal.DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) { db.execSQL(DatabaseValues_personal.TABLE_NOTES_PERSONAL_CREATE);}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL(DatabaseValues_personal.TABLE_NOTES_PERSONAL_DROP);
    onCreate(db);
}

public void addNote(Note note){
    SQLiteDatabase db_personal = this.getWritableDatabase();

    ContentValues noteValues = new ContentValues();
    noteValues.put(DatabaseValues_personal.NOTES_TITLE_PERSONAL, note.getTitle());
    noteValues.put(DatabaseValues_personal.NOTES_DESCRIPTION_PERSONAL, note.getDescription());

    db_personal.insert(DatabaseValues_personal.TABLE_NOTES_PERSONAL, null, noteValues);
    db_personal.close();
}

public void updateNote(Note note){
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues noteValues = new ContentValues();
    noteValues.put(DatabaseValues_personal.NOTES_TITLE_PERSONAL, note.getTitle());
    noteValues.put(DatabaseValues_personal.NOTES_DESCRIPTION_PERSONAL, note.getDescription());

    db.update(DatabaseValues_personal.TABLE_NOTES_PERSONAL, noteValues, DatabaseValues_personal.NOTES_ID_PERSONAL + " = ?", new String[]{String.valueOf(note.getId())});
    db.close();
}

public void deleteNote(String id){
    SQLiteDatabase db = this.getWritableDatabase();

    String deletequery= "DELETE FROM " + DatabaseValues_personal.TABLE_NOTES_PERSONAL + " WHERE " + DatabaseValues_personal.NOTES_ID_PERSONAL + " = '" + id + "'";

    db.execSQL(deletequery);
    db.close();
}

public List<Note> getAllNotes(){
    List<Note> notes = new ArrayList<>();

    SQLiteDatabase db = this.getReadableDatabase();

    String selectQuery= "SELECT * FROM " + DatabaseValues_personal.TABLE_NOTES_PERSONAL;
    Cursor cursor = db.rawQuery(selectQuery, null);

    if (cursor.moveToFirst()){
        do{

            Note note = new Note();
            note.setId(Integer.parseInt(cursor.getString(0)));
            note.setTitle(cursor.getString(1));
            note.setDescription(cursor.getString(2));

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

    cursor.close();
    db.close();

    return notes;


}
}

DatabaseValues_personal.class

 package dbms.vit.myapplication;



    public class DatabaseValues_personal {

    public static final int DATABASE_VERSION = 13;

    public static final String DATABASE_NAME = "personal_note";

    public static final String TABLE_NOTES_PERSONAL = "personal_notes";

    public static final String NOTES_ID_PERSONAL = "id";
    public static final String NOTES_TITLE_PERSONAL = "title_personal";
    public static final String NOTES_DESCRIPTION_PERSONAL = "description_personal";
    public static final String NOTES_DATE_PERSONAL = "data_personal";

    public static final String TABLE_NOTES_PERSONAL_CREATE = "CREATE TABLE IF NOT EXISTS " + TABLE_NOTES_PERSONAL + "( " + NOTES_ID_PERSONAL + " INTEGER PRIMARY KEY, " + NOTES_TITLE_PERSONAL + " TEXT, " + NOTES_DESCRIPTION_PERSONAL + " TEXT, " + NOTES_DATE_PERSONAL + " INTEGER NOT NULL DEFAULT (strftime('%s','now')) ";

    public static final String TABLE_NOTES_PERSONAL_DROP = "DROP TABLE IF EXISTS " + TABLE_NOTES_PERSONAL;

    }

Android编程（将数据库中的时间戳添加到ListView）

0 个答案: