文本数据的存储添加删除
登陆注册
SQlite的创建
数据listview列表的显示
demo地址
My日记本App.zip-Android文档类资源-CSDN下载
package com.example.mydiaryapp;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.DatabaseErrorHandler;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MySqlHelper extends SQLiteOpenHelper {
String sql = “create table note(id integer primary key autoincrement ,title text,content text);”;
SQLiteDatabase db;
public MySqlHelper(@Nullable Context context, @Nullable String name, @Nullable SQLiteDatabase.CursorFactory factory, int version) {
super(context, name, factory, version);
db = getWritableDatabase();
}
public MySqlHelper(Context context) {
this(context, “noteDb”, null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(sql);
}
public HashMap
public void writeNote(String id, String title, String content) {
ContentValues contentValues = new ContentValues();
contentValues.put(“title”, title);
contentValues.put(“content”, content);
if (id != null) {
db.update(“note”, contentValues, “id=?”, new String[]{id});
} else {
long insert_id = db.insert(“note”, null, contentValues);
}
}
public List
if (cursor.getCount() > 0) {
cursor.moveToFirst();
int id_idx = cursor.getColumnIndex(“id”);
int title_idx = cursor.getColumnIndex(“title”);
int content_idx = cursor.getColumnIndex(“content”);
do {
Map map = new HashMap
} while (cursor.moveToNext());
}
return notes_data;
}
public void deleteNote(String id) {
db.delete(“note”, “id=?”, new String[]{id});
}
public void flushDb() {
db.delete(“note”, “1=1”, null);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
Original: https://blog.csdn.net/c04250425/article/details/121238002
Author: 睡不饱的我
Title: Android 记事本
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