Shulou(Shulou.com)06/01 Report--

This article analyzes "how to implement a simple word book Android App based on Java". The content is detailed and easy to understand. Friends who are interested in "how to achieve a simple word book Android App based on Java" can follow the editor's train of thought to read it slowly and deeply. I hope it will be helpful to you after reading. Let's learn more about "how to implement a simple word book Android App based on Java" with the editor.

Layout design

Word book main interface

Code AddDanciActivity.java

Activity of the main interface of the word book

Import androidx.appcompat.app.AppCompatActivity;import android.content.ContentValues;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.ListView;import android.widget.SimpleAdapter;import android.widget.Toast;import java.util.ArrayList;import java.util.HashMap;import java.util.Map; public class AddDanciActivity extends AppCompatActivity {private EditText wordedit; private EditText yisiedit; private Button add_btn Private Button quxiao_btn; private Button shanchu_btn; private ListView listview; private DBOpenHelper dbOpenHelper;// statement @ Override protected void onCreate (Bundle savedInstanceState) {super.onCreate (savedInstanceState); setContentView (R.layout.activity_add_danci); dbOpenHelper = new DBOpenHelper (AddDanciActivity.this, "db_dict", null, 1); / / instantiate, create database wordedit = (EditText) findViewById (R.id.addword_edit) Yisiedit = (EditText) findViewById (R.id.fanyiword_edit); listview = (ListView) findViewById (R.id.add_list); add_btn = (Button) findViewById (R.id.add_btn); quxiao_btn = (Button) findViewById (R.id.quxiao_btn); shanchu_btn = (Button) findViewById (R.id.shanchu_btn) Quxiao_btn.setOnClickListener (new View.OnClickListener () {@ Override public void onClick (View v) {Toast.makeText (AddDanciActivity.this, "return to the word book main interface", Toast.LENGTH_SHORT) .show (); finish ();}}) Shanchu_btn.setOnClickListener (new View.OnClickListener () {@ Override public void onClick (View v) {String word = wordedit.getText () .toString (); String ys = yisiedit.getText () .toString () If (word.equals (")) {Toast.makeText (AddDanciActivity.this," empty word ", Toast.LENGTH_SHORT). Show ();} else {deleteData (dbOpenHelper.getReadableDatabase (), word); Toast.makeText (AddDanciActivity.this," deleted successfully ", Toast.LENGTH_SHORT) .show () }); add_btn.setOnClickListener (new View.OnClickListener () {@ Override public void onClick (View v) {String word = wordedit.getText () .toString (); String ys = yisiedit.getText () .toString () If (word.equals (") | | ys.equals (")) {Toast.makeText (AddDanciActivity.this, "filled in or interpreted as empty", Toast.LENGTH_SHORT) .show ();} else {insertData (dbOpenHelper.getReadableDatabase (), word, ys) / / insert new words Toast.makeText (AddDanciActivity.this, "successful addition of new words", Toast.LENGTH_SHORT). Show (); renew ();} / insert data method private void insertData (SQLiteDatabase sqLiteDatabase, String word, String ys) {ContentValues values = new ContentValues () Values.put ("word", word); / Save the word values.put ("detail", ys); sqLiteDatabase.insert ("tb_dict", null, values); / / perform the insert operation renew ();} private void deleteData (SQLiteDatabase sqLiteDatabase, String word) {ContentValues values = new ContentValues (); String [] args = {String.valueOf (word)} SqLiteDatabase.delete ("tb_dict", "word=?", args); / / perform delete operation renew ();} @ Override protected void onDestroy () {super.onDestroy (); if (dbOpenHelper! = null) {dbOpenHelper.close () / / close}} public void renew () {Cursor cursor = dbOpenHelper.getReadableDatabase (). Query ("tb_dict", null, null); ArrayList resultList = new ArrayList (); while (cursor.moveToNext ()) {Map map = new HashMap (); map.put ("word", cursor.getString (1)) Map.put ("interpret", cursor.getString (2)); resultList.add (map);} if (resultList = = null | | resultList.size () = = 0) {Toast.makeText (AddDanciActivity.this, "Unfortunately, there is no relevant record!" , Toast.LENGTH_SHORT) .show ();} else {SimpleAdapter simpleAdapter = new SimpleAdapter (AddDanciActivity.this, resultList, R.layout.item, new String [] {"word", "interpret"}, new int [] {R.id.textView, R.id.textView2}); listview.setAdapter (simpleAdapter);}} @ Override protected void onStart () {super.onStart () Renew ();}} DBOpenHelper.java

SQLite database is used, and Android comes with a lightweight database, which is very easy to use.

Import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;import android.util.Log;import androidx.annotation.Nullable; public class DBOpenHelper extends SQLiteOpenHelper {final String CREATE_TABLE_SQL = "create table tb_dict (_ id integer primary key autoincrement,word,detail)"; / / define the public DBOpenHelper (@ Nullable Context context, @ Nullable String name, @ Nullable SQLiteDatabase.CursorFactory factory, int version) {super (context, name, null, version) that creates the table. } @ Override public void onCreate (SQLiteDatabase db) {db.execSQL (CREATE_TABLE_SQL); / / create a datasheet of words} @ Override public void onUpgrade (SQLiteDatabase db, int oldVersion, int newVersion) {Log.i ("dictionary", "--version update" + oldVersion + "-->" + newVersion);}}

Effect picture

What are the characteristics of Java? what are the characteristics of Java? what is the 1.Java language that represents the static object-oriented programming language? it implements the object-oriented theory and allows programmers to carry out complex programming in an elegant way of thinking. 2.Java has the characteristics of simplicity, object-oriented, distributed, security, platform independence and portability, dynamic and so on. 3. Using Java, you can write desktop applications, Web applications, distributed systems, embedded system applications, and so on.

On how to achieve a simple word based on Java Android App to share here, I hope that the above content can make you improve. If you want to learn more knowledge, please pay more attention to the editor's updates. Thank you for following the website!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.