APP
实现效果图：
（1）activity_main
<?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"
>
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/bookname">
</EditText>
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/bookauthor">
</EditText>
<ListView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/booklist">
</ListView>
</LinearLayout>
（3）MainActivity
public class MainActivity extends AppCompatActivity implements OnItemClickListener{
private BookDB mBookDB;
private Cursor mCursor;
private EditText bookName;
private EditText bookAuthor;
private ListView bookList;
private int BOOK_ID=0;
private static final int MENU_ADD = Menu.FIRST;
private static final int MENU_DELETE = Menu.FIRST+1;
private static final int MENU_UPDATE = Menu.FIRST+2;
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.add(Menu.NONE, MENU_ADD, 0, "ADD");
menu.add(Menu.NONE, MENU_DELETE, 0, "DELETE");
menu.add(Menu.NONE, MENU_UPDATE, 0, "UPDATE");
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
switch(item.getItemId()){
case MENU_ADD:
add();
break;
case MENU_DELETE:
delete();
break;
case MENU_UPDATE:
update();
break;
}
return true;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.sqlite_activity);
setUpViews();
}
public void setUpViews(){
mBookDB = new BookDB(this);
//进入这个界面 直接查询数据库
mCursor = mBookDB.select();
bookName = (EditText)findViewById(R.id.bookname);
bookAuthor = (EditText)findViewById(R.id.bookauthor);
bookList = (ListView)findViewById(R.id.booklist);
// System.out.println(bookName);
// System.out.println(bookAuthor);
// System.out.println(bookList);
BookListAdapter adapter = new BookListAdapter(SQLiteDatabaseDemo.this,mCursor);
bookList.setAdapter(adapter);
bookList.setOnItemClickListener(SQLiteDatabaseDemo.this);
}
//listview点击事件
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
mCursor.moveToPosition(position);
BOOK_ID = mCursor.getInt(0);
bookName.setText(mCursor.getString(1));
bookAuthor.setText(mCursor.getString(2));
}
public void add(){
//获取输入的内容
String bookname = bookName.getText().toString();
String author = bookAuthor.getText().toString();
if(bookname.equals("")||author.equals("")) return;
mBookDB.add(bookname, author);
//Requery 方法是通过重新查询窗体或控件的数据源更新基于指定窗体的数据
mCursor.requery();
//对listview自动刷新
bookList.invalidateViews();
bookName.setText("");
bookAuthor.setText("");
Toast.makeText(this, "add success", Toast.LENGTH_SHORT).show();
}
public void delete(){
String bookname = bookName.getText().toString();
String author = bookAuthor.getText().toString();
if(BOOK_ID == 0) return;
mBookDB.delete(BOOK_ID);
mCursor.requery();
// //对listview自动刷新
bookList.invalidateViews();
bookName.setText("");
bookAuthor.setText("");
Toast.makeText(this, "delete success", Toast.LENGTH_SHORT).show();
}
public void update(){
String bookname = bookName.getText().toString();
String author = bookAuthor.getText().toString();
if(bookname.equals("")||author.equals("")) return;
mBookDB.update(BOOK_ID, bookname, author);
mCursor.requery();
bookList.invalidateViews();
bookName.setText("");
bookAuthor.setText("");
Toast.makeText(this, "update success", Toast.LENGTH_SHORT).show();
}
public class BookListAdapter extends BaseAdapter{
private Context mContext;
private Cursor mCursor;
public BookListAdapter(Context context,Cursor cursor){
mContext = context;
mCursor = cursor;
}
@Override
public int getCount() {
//数据库数据条目
return mCursor.getCount();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
mCursor.moveToPosition(position);
TextView mTextView = new TextView(mContext);
mTextView.setText("序号"+mCursor.getString(1)+"内容"+mCursor.getString(2));
return mTextView;
}
}
}（1）数据库工具类BookDB
public class BookDB extends SQLiteOpenHelper{
//数据库名称
private final static String DATABASE_NAME = "BOOKS.db";
//数据库版本号
private final static int DATABASSE_VERSION=1;
//表名
private final static String TABLE_NAME = "books_table";
//书籍名称
private final static String BOOK_NAME = "book_name";
///书籍的id
private final static String BOOK_ID = "book_id";
//作者
private final static String BOOK_AUTHOR = "book_author";
//构造方法
public BookDB(Context context) {
//上下文 数据库名称 工厂类 数据库的版本号
super(context, DATABASE_NAME,null,DATABASSE_VERSION);
}
//第一次进来 如果没有 则创建数据库 如果有就打开
@Override
public void onCreate(SQLiteDatabase db) {
String sql = "CREATE TABLE "+ TABLE_NAME+" ("+BOOK_ID+
" INTEGER primary key autoincrement,"+BOOK_NAME+" text,"+BOOK_AUTHOR+" text);";
//执行数据库
db.execSQL(sql);
}
//数据库更新
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
String sql = "DROP TABLE IF EXISTS "+TABLE_NAME;
db.execSQL(sql);
onCreate(db);
}
//查询数据库内容
public Cursor select(){
//申请数据库的权限 读写
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_NAME, null, null, null, null, null, null);
return cursor;
}
//添加
public long add(String bookname,String author){
SQLiteDatabase db = this.getWritableDatabase();
//添加数据 键值对
ContentValues cv =new ContentValues();
cv.put(BOOK_NAME, bookname);
cv.put(BOOK_AUTHOR, author);
long row = db.insert(TABLE_NAME, null, cv);
return row;
}
//根据id删除
public void delete(int id){
SQLiteDatabase db = this.getWritableDatabase();
String where = BOOK_ID+ "=?";
String[] whereValue = {Integer.toString(id)};
db.delete(TABLE_NAME, where, whereValue);
}
//更新
public void update(int id,String bookname,String bookauthor){
SQLiteDatabase db =this.getWritableDatabase();
ContentValues cv =new ContentValues();
cv.put(BOOK_NAME, bookname);
cv.put(BOOK_AUTHOR, bookauthor);
String where = BOOK_ID+"=?";
String[] whereValue = {Integer.toString(id)};
db.update(TABLE_NAME, cv, where, whereValue);
}
}
本文摘自 ：https://blog.51cto.com/u
