功能实现单词本的添加与查询单词
查询结果图如下
代码如下：
查询结果使用的activity是dialog风格的activity，在manifest文件中如此配置
<activity android:name=".ResultActivity" android:label="查询结果" android:theme="@android:style/Theme.Dialog"></activity> 要实现数据库的增删改查，需要三步：
1.继承SQLiteOpenHelper复写onCreate方法，一般在里面实现创建表的工作。
2.通过SQLiteOpenHelper的getReadableDatabase或者getWriteableDatabase方法创建数据库
3.调用数据库增删改查方法进行数据操作
java代码如下
package com.example.mysqliitedatabase; import android.provider.BaseColumns; import android.provider.SyncStateContract.Columns; //定义数据库表的名字及表的列名 public class Words { static class MyColumn implements BaseColumns{ final static String TABLE_NAME="dict"; final static String _ID="_id"; final static String WORD="word"; final static String DETAIL="detail"; } } package com.example.mysqliitedatabase; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteDatabase.CursorFactory; import android.database.sqlite.SQLiteOpenHelper; public class MySqliteDatabaseHelper extends SQLiteOpenHelper { String CreateTable="create table dict"+"("+Words.MyColumn._ID+"integer primary key ,"+Words.MyColumn.WORD+","+Words.MyColumn.DETAIL+")"; public MySqliteDatabaseHelper(Context context, String name, CursorFactory factory, int version) { super(context, name, factory, version); // TODO Auto-generated constructor stub } @Override public void onCreate(SQLiteDatabase db) { // TODO Auto-generated method stub db.execSQL(CreateTable); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub } } package com.example.mysqliitedatabase; import java.util.ArrayList; import java.util.HashMap; import java.util.Map; import java.util.Stack; import android.os.Bundle; import android.app.Activity; import android.content.ContentValues; import android.content.Intent; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.text.TextUtils; //import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; public class MainActivity extends Activity { private EditText wordString; private EditText detailString; private EditText queryString; private SQLiteDatabase database; private Button addButton; private Button queryButton; String[] returnColums={Words.MyColumn.WORD,Words.MyColumn.DETAIL}; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final MySqliteDatabaseHelper datanaseHelper=new MySqliteDatabaseHelper(getApplicationContext(), "dict.db",null,1); wordString=(EditText) findViewById(R.id.editText1); detailString=(EditText) findViewById(R.id.editText2); queryString=(EditText) findViewById(R.id.editText3); addButton= (Button) findViewById(R.id.button1); queryButton=(Button) findViewById(R.id.button2); addButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub final String word=wordString.getText().toString(); final String detail=detailString.getText().toString(); database=datanaseHelper.getWritableDatabase(); ContentValues contentValues=new ContentValues(); contentValues.put(Words.MyColumn.WORD,word); contentValues.put(Words.MyColumn.DETAIL,detail); database.insert("dict", null,contentValues); Toast.makeText(getApplicationContext(), "add success",1000).show(); } }); queryButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub database=datanaseHelper.getWritableDatabase(); String query=queryString.getText().toString(); String[] selectionArgs = null; String selection = null; Cursor cursor; if (!TextUtils.isEmpty(query)) { selectionArgs=new String[]{query}; selection=Words.MyColumn.WORD+"= ?"; } cursor=database.query("dict", returnColums, selection, selectionArgs, null,null,null); ArrayList<Map<String,String>> list=new ArrayList<Map<String,String>>(); if (cursor!=null) { while (cursor.moveToNext()) { Map<String,String> map=new HashMap<String, String>(); int wordIndex=cursor.getColumnIndex(Words.MyColumn.WORD); int detailIndex=cursor.getColumnIndex(Words.MyColumn.DETAIL); map.put(Words.MyColumn.WORD,cursor.getString(wordIndex)); map.put(Words.MyColumn.DETAIL,cursor.getString(detailIndex)); list.add(map); } Toast.makeText(getApplicationContext(), "query success",1000).show(); Intent intent=new Intent(getApplicationContext(), ResultActivity.class); Bundle bundle=new Bundle(); bundle.putSerializable("data",list); intent.putExtras(bundle); startActivity(intent); } else { Toast.makeText(getApplicationContext(), "cursor is null",1000).show(); } } }); } } package com.example.mysqliitedatabase; import java.util.ArrayList; import java.util.List; import java.util.Map; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.widget.ListView; import android.widget.SimpleAdapter; public class ResultActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); ListView listView=new ListView(getApplicationContext()); setContentView(listView); Intent intent=getIntent(); ArrayList<Map<String,String>> list=(ArrayList<Map<String, String>>) intent.getSerializableExtra("data"); SimpleAdapter adapter=new SimpleAdapter(getApplicationContext(), list, R.layout.main, new String[]{Words.MyColumn.WORD,Words.MyColumn.DETAIL},new int[]{R.id.text1,R.id.text2}); listView.setAdapter(adapter); } }