SQLite和listview

首先创建一个类Sqlite继承自SQLiteOpenHelper，复写onCreate方法，在方法体中创建数据库的表格：

public class Sqlite extends SQLiteOpenHelper {

public Sqlite(Context context) {

super(context, "db", null, 1);

}

@Override

public void onCreate(SQLiteDatabase db) {

db.execSQL("create table user(_id integer primary key autoincrement,name text,sex text)");

}

@Override

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}

}

主布局中最上面定义一个listview，下面定义两个textview和两个editview：

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical"

tools:context=".MainActivity">

<ListView

android:id="@android:id/list"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:layout_weight="1"/>

<LinearLayout

android:layout_width="match_parent"

android:layout_height="wrap_content">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="name"/>

<EditText

android:id="@+id/etName"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_weight="1"/>

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="sex"/>

<EditText

android:id="@+id/etSex"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_weight="1"/>

<Button

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:id="@+id/button"

android:text="确定"/>

</LinearLayout>

</LinearLayout>



接着，再新建一个布局文件，名为ueser_list_cell.xml：

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical" android:layout_width="match_parent"

android:layout_height="match_parent">

<TextView

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceLarge"

android:text="Large Text"

android:id="@+id/tvName" />

<TextView

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceMedium"

android:text="Medium Text"

android:id="@+id/tvSex" />

</LinearLayout>

注意：activity是继承自ListActivity，所以主布局有且仅能有一个listview，并且id的定义必须为

android:id="android:id/list"

public class MainActivity extends ListActivity {

private SimpleCursorAdapter simpleCursorAdapter;

private EditText etName,etSex;

private Sqlite db;

private SQLiteDatabase dbRead,dbWrite;

private ListView list;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

etName = (EditText)findViewById(R.id.etName);

etSex = (EditText)findViewById(R.id.etSex);

list = (ListView) findViewById(android.R.id.list);

// 继承自ListActivity，listview的id必须是android:id/list，所以这里找的id是android.R.id.list，

// 即系统的id

findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

ContentValues cv = new ContentValues();

cv.put("name",etName.getText().toString());

cv.put("sex",etSex.getText().toString());

dbWrite.insert("user",null,cv);

// 以上代码是把用户输入的名字和性别存储到数据库

refreshListView();

}

});

db = new Sqlite(this);

dbRead = db.getReadableDatabase();

dbWrite = db.getWritableDatabase();

simpleCursorAdapter = new SimpleCursorAdapter(this,R.layout.user_list_cell,null,new String[]{"name","sex"},new int[]{R.id.tvName,R.id.tvSex},0);

list.setAdapter(simpleCursorAdapter);

refreshListView();

getListView().setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {

@Override

public boolean onItemLongClick(AdapterView<?> parent, View view, final int position, long id) {

new AlertDialog.Builder(MainActivity.this)

.setTitle("提醒")

.setMessage("确定要删除吗？")

.setNegativeButton("取消",null)

.setPositiveButton("确定", new DialogInterface.OnClickListener() {

@Override

public void onClick(DialogInterface dialog, int which) {

Cursor c = simpleCursorAdapter.getCursor();

c.moveToPosition(position);

int itemId = c.getInt(c.getColumnIndex("_id"));

dbWrite.delete("user","_id=?",new String[]{itemId+""});

refreshListView();

}

}).create().show();

return true;

}

});

}

public void refreshListView(){

Cursor c = dbRead.query("user",null,null,null,null,null,null);

simpleCursorAdapter.changeCursor(c);

}

}