SQLite 小例子。

     这是我在网站看到过一个网友做的SQLite一个小程序，觉得写的不错，以供提示参考，所以把转载下来了。其实就是一个小收藏夹。

代码如下：

 

ActivityMain_1.java

public class ActivityMain_1 extends Activity {//声明EditText实例private EditText et1,et2,et3;//声明Button实例private Button button;@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.main_1);//根据ID获得实例对象et1 = (EditText) findViewById(R.id.EditText01);et2 = (EditText) findViewById(R.id.EditText02);et3 = (EditText) findViewById(R.id.EditText03);button = (Button) findViewById(R.id.button);//事件button.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {String name=et1.getText().toString();String url =et2.getText().toString();String desc = et3.getText().toString();ContentValues values = new ContentValues();values.put("name", name);values.put("url", url);values.put("desc", desc);//实例化数据库帮助类DBHelper helper = new DBHelper(getApplicationContext());//打开数据库helper.open(); //插入数据helper.insert(values);//实例化IntentIntent intent = new Intent(ActivityMain_1.this,QueryActivity.class);startActivity(intent);helper.close();}});}} 

QueryActivity.java

public class QueryActivity extends ListActivity {private ListView listView;private Cursor c; @Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);//setContentView(R.layout.row);//实例化数据库帮助类final DBHelper help = new DBHelper(this);help.open();c= help.query(); query();//提示对话框final AlertDialog.Builder builder = new AlertDialog.Builder(this);listView.setOnItemClickListener(new OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> parent, View view,int position, long id) {final long temp = id;builder.setMessage("真的要删除该条记录吗？").setPositiveButton("是", new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {System.out.println("yes");help.del((int)temp);//重新查询//query();Cursor c = help.query();//列表项数组String[] from ={"_id","name","url","desc"};//列表项IDint[] to ={R.id.text0,R.id.text1,R.id.text2,R.id.text3};//适配器SimpleCursorAdapter adapter = new SimpleCursorAdapter(getApplicationContext(),R.layout.row,c,from,to);ListView listView = getListView();listView.setAdapter(adapter);}}).setNegativeButton("否", new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stub}});builder.create();builder.show();}});}@Overrideprotected void onStop() {// TODO Auto-generated method stubsuper.onStop();}public void query(){//列表项数组String[] from ={"_id","name","url","desc"};//列表项IDint[] to ={R.id.text0,R.id.text1,R.id.text2,R.id.text3};//适配器SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,R.layout.row,c,from,to);//adapter.notifyDataSetChanged();//列表视图 listView = getListView();//为列表视图添加适配器listView.setAdapter(adapter);}} 

 

 

 

DBHelper.java

public class DBHelper extends SQLiteOpenHelper {private static final String DB_NAME="coll.db";//表名private static final String TBL_NAME="logtable";//创建SQL语句private static final String CREATE_TBL = "create table logtable " +"(_id integer primary key autoincrement,name text,url text,desc text)";//SQLiteDatabase实例private SQLiteDatabase db;public DBHelper(Context context) {super(context, DB_NAME, null, 2);}@Overridepublic void onCreate(SQLiteDatabase db) {db.execSQL(CREATE_TBL);}//打开数据库public void open(){db = getWritableDatabase();}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {// TODO Auto-generated method stub}//插入方法public void insert(ContentValues values){db.insert(TBL_NAME, null, values);}//查询方法public Cursor query(){Cursor c = db.query(TBL_NAME, null, null, null, null, null, null);return c;}//删除方法public void del(int id){db.delete(TBL_NAME, "_id=?", new String[]{String.valueOf(id)});}//关闭数据库public void close(){if (db != null){db.close();}}} 

 

 

main_1.xml

<?xml version="1.0" encoding="UTF-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical"android:layout_width="fill_parent"android:layout_height="fill_parent"><TextViewandroid:id="@+id/TextView01"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="网站名称"/><EditTextandroid:id="@+id/EditText01"android:layout_width="fill_parent"android:layout_height="wrap_content"/><TextViewandroid:id="@+id/TextView02"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="URL"/><EditTextandroid:id="@+id/EditText02"android:layout_width="fill_parent"android:layout_height="wrap_content"/><TextViewandroid:id="@+id/TextView03"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="网站描述"/><EditTextandroid:id="@+id/EditText03"android:layout_width="fill_parent"android:layout_height="wrap_content"android:height="100px"/><Buttonandroid:id="@+id/button"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="添加"/></LinearLayout> 

自定义布局：row.xml

<?xml version="1.0" encoding="UTF-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="horizontal"android:layout_width="fill_parent"android:layout_height="fill_parent"android:layout_gravity="center_vertical"><TextViewandroid:id="@+id/text0"android:layout_width="wrap_content"android:layout_height="wrap_content"android:paddingRight="10px"/><TextViewandroid:id="@+id/text1"android:layout_width="wrap_content"android:layout_height="wrap_content"android:paddingRight="10px"/><TextViewandroid:id="@+id/text2"android:layout_width="wrap_content"android:layout_height="wrap_content"android:paddingRight="10px"/><TextViewandroid:id="@+id/text3"android:layout_width="wrap_content"android:layout_height="wrap_content"android:paddingRight="10px"/></LinearLayout> 

 

结果如图所示：