学步园

import android.app.Activity;<br /> import android.content.ContentValues;<br /> import android.database.Cursor;<br /> import android.database.sqlite.SQLiteDatabase;<br /> import android.graphics.Color;<br /> import android.os.Bundle;<br /> import android.view.KeyEvent;<br /> import android.widget.LinearLayout;<br /> import android.widget.ListAdapter;<br /> import android.widget.ListView;<br /> import android.widget.SimpleCursorAdapter;</p> <p>public class Activity01 extends Activity {<br /> private static int miCount = 0;</p> <p> /* 数据库对象 */<br /> private SQLiteDatabase mSQLiteDatabase = null;</p> <p> private final static String DATABASE_NAME = "SQLite.db";</p> <p> /* 表名 */<br /> private final static String TABLE_NAME = "table1";</p> <p> /* 表中的字段 */<br /> private final static String TABLE_ID = "_id";</p> <p> private final static String TABLE_NUM = "num";</p> <p> private final static String TABLE_DATA = "data";</p> <p> /* 创建表的sql语句 */<br /> private final static String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME<br /> + " (" + TABLE_ID + " INTEGER PRIMARY KEY," + TABLE_NUM<br /> + " INTERGER," + TABLE_DATA + " TEXT)";</p> <p> /* 线性布局 */<br /> LinearLayout m_LinearLayout = null;</p> <p> /* 列表视图-显示数据库中的数据 */<br /> ListView m_ListView = null;</p> <p> @Override<br /> public void onCreate(Bundle savedInstanceState) {<br /> super.onCreate(savedInstanceState);</p> <p> /* 创建LinearLayout布局对象 */<br /> m_LinearLayout = new LinearLayout(this);<br /> /* 设置布局LinearLayout的属性 */<br /> m_LinearLayout.setOrientation(LinearLayout.VERTICAL);<br /> m_LinearLayout.setBackgroundColor(android.graphics.Color.BLACK);</p> <p> /* 创建ListView对象 */<br /> m_ListView = new ListView(this);<br /> LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(<br /> LinearLayout.LayoutParams.FILL_PARENT,<br /> LinearLayout.LayoutParams.WRAP_CONTENT);<br /> m_ListView.setBackgroundColor(Color.BLACK);</p> <p> /* 添加m_ListView到m_LinearLayout布局 */<br /> m_LinearLayout.addView(m_ListView, param);</p> <p> /* 设置显示m_LinearLayout布局 */<br /> setContentView(m_LinearLayout);</p> <p> // 打开已经存在的数据库<br /> mSQLiteDatabase = this.openOrCreateDatabase(DATABASE_NAME,<br /> MODE_PRIVATE, null);</p> <p> // 获取数据库Phones的Cursor<br /> try {<br /> /* 在数据库mSQLiteDatabase中创建一个表 */<br /> mSQLiteDatabase.execSQL(CREATE_TABLE);<br /> } catch (Exception e) {<br /> UpdataAdapter();<br /> }<br /> }</p> <p> public boolean onKeyUp(int keyCode, KeyEvent event) {<br /> switch (keyCode) {<br /> case KeyEvent.KEYCODE_DPAD_LEFT:<br /> AddData();<br /> break;<br /> case KeyEvent.KEYCODE_DPAD_RIGHT:<br /> DeleteData();<br /> break;<br /> case KeyEvent.KEYCODE_1:<br /> UpData();<br /> break;<br /> case KeyEvent.KEYCODE_2:<br /> DeleteTable();<br /> break;<br /> case KeyEvent.KEYCODE_3:<br /> DeleteDataBase();<br /> break;<br /> }<br /> return true;<br /> }</p> <p> /* 删除数据库 */<br /> public void DeleteDataBase() {<br /> this.deleteDatabase(DATABASE_NAME);<br /> this.finish();<br /> }</p> <p> /* 删除一个表 */<br /> public void DeleteTable() {<br /> mSQLiteDatabase.execSQL("DROP TABLE " + TABLE_NAME);<br /> this.finish();<br /> }</p> <p> /* 更新一条数据 */<br /> public void UpData() {<br /> ContentValues cv = new ContentValues();<br /> cv.put(TABLE_NUM, miCount);<br /> cv.put(TABLE_DATA, "修改后的数据" + miCount);</p> <p> /* 更新数据 */<br /> mSQLiteDatabase.update(TABLE_NAME, cv,<br /> TABLE_NUM + "=" + Integer.toString(miCount - 1), null);</p> <p> UpdataAdapter();<br /> }</p> <p> /* 向表中添加一条数据 */<br /> public void AddData() {<br /> ContentValues cv = new ContentValues();<br /> cv.put(TABLE_NUM, miCount);<br /> cv.put(TABLE_DATA, "测试数据库数据" + miCount);<br /> /* 插入数据 */<br /> mSQLiteDatabase.insert(TABLE_NAME, null, cv);<br /> miCount++;<br /> UpdataAdapter();<br /> }</p> <p> /* 从表中删除指定的一条数据 */<br /> public void DeleteData() {<br /> /* 删除数据 */<br /> mSQLiteDatabase.execSQL("DELETE FROM" + TABLE_NAME + "WHERE _id="<br /> + Integer.toString(miCount));</p> <p> miCount--;<br /> if (miCount < 0) {<br /> miCount = 0;<br /> }</p> <p> UpdataAdapter();<br /> }</p> <p> /* 更行试图显示 */<br /> public void UpdataAdapter() {<br /> // 获取数据库Phones的Cursor<br /> Cursor cur = mSQLiteDatabase.query(TABLE_NAME, new String[] { TABLE_ID,<br /> TABLE_NUM, TABLE_DATA }, null, null, null, null, null);</p> <p> miCount = cur.getCount();<br /> if (cur != null && cur.getCount() >= 0) {<br /> // ListAdapter是ListView和后台数据的桥梁<br /> ListAdapter adapter = new SimpleCursorAdapter(this,<br /> // 定义List中每一行的显示模板<br /> // 表示每一行包含两个数据项<br /> android.R.layout.simple_list_item_2,<br /> // 数据库的Cursor对象<br /> cur,<br /> // 数据库的Cursor对象<br /> new String[] { TABLE_NUM, TABLE_DATA },<br /> // 与NAME和NUMBER对应的Views<br /> new int[] { android.R.id.text1, android.R.id.text2 });<br /> /* 将adapter添加到m_ListView中 */<br /> m_ListView.setAdapter(adapter);<br /> }<br /> }</p> <p> /* 按键事件处理 */<br /> public boolean onKeyDown(int keyCode, KeyEvent event) {<br /> if (keyCode == KeyEvent.KEYCODE_BACK) {<br /> /* 关闭数据库（易忘） */<br /> mSQLiteDatabase.close();<br /> this.finish();<br /> return true;<br /> }<br /> return super.onKeyDown(keyCode, event);<br /> }</p> <p>}

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  上面的测试数据8是 之前 创建的。。