Da.java
public class Db extends SQLiteOpenHelper {
public Db(Context context) {
super(context, "db", null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE user2(" +
"_id INT DEFAULT 0," +
"name TEXT DEFAULT \"\"," +
"sex TEXT DEFAULT \"\")");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
MainActivity.java
public class MainActivity extends AppCompatActivity {
private SimpleCursorAdapter mAdapter;
private ListView listView;
private Button btn_add;
private Button btn_delete;
private Button btn_back;
private EditText et_id;
private EditText et_name;
private EditText et_sex;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_add = (Button) findViewById(R.id.btn_add);
btn_delete = (Button) findViewById(R.id.btn_delete);
listView = (ListView) findViewById(R.id.list);
btn_add.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
addData();
refleshListView();
}
});
btn_delete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
deleteData();
refleshListView();
}
});
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// Toast.makeText(MainActivity.this,""+position,Toast.LENGTH_SHORT).show();
int positions = position + 1;
Db db = new Db(MainActivity.this);
SQLiteDatabase dbWrite = db.getWritableDatabase();
dbWrite.delete("user2","_id=?",new String[]{""+positions});
dbWrite.close();
refleshListView();
}
});
}
public void addData() {
btn_back = (Button) findViewById(R.id.btn_back);
et_id = (EditText) findViewById(R.id.et_id);
et_name = (EditText) findViewById(R.id.et_name);
et_sex = (EditText) findViewById(R.id.et_sex);
btn_add = (Button) findViewById(R.id.btn_add);
btn_delete = (Button) findViewById(R.id.btn_delete);
listView = (ListView) findViewById(R.id.list);
btn_add.setVisibility(View.GONE);
btn_delete.setVisibility(View.GONE);
listView.setVisibility(View.GONE);
btn_back.setVisibility(View.VISIBLE);
et_id.setVisibility(View.VISIBLE);
et_name.setVisibility(View.VISIBLE);
et_sex.setVisibility(View.VISIBLE);
btn_back.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
btn_add.setVisibility(View.VISIBLE);
btn_delete.setVisibility(View.VISIBLE);
listView.setVisibility(View.VISIBLE);
btn_back.setVisibility(View.GONE);
et_id.setVisibility(View.GONE);
et_name.setVisibility(View.GONE);
et_sex.setVisibility(View.GONE);
String id = et_id.getText().toString(),
name =et_name.getText().toString(),
sex = et_sex.getText().toString();
Db db = new Db(MainActivity.this);
SQLiteDatabase dbWrite = db.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put("_id", id);
cv.put("name", name);
cv.put("sex", sex);
dbWrite.insert("user2", null, cv);
dbWrite.close();
refleshListView();
}
});
// String id = et_id.getText().toString(),
// name =et_name.getText().toString(),
// sex = et_sex.getText().toString();
//
//
// Db db = new Db(MainActivity.this);
// SQLiteDatabase dbWrite = db.getWritableDatabase();
//
// ContentValues cv = new ContentValues();
// cv.put("_id",id);
// cv.put("name", name);
// cv.put("sex", sex);
// dbWrite.insert("user2", null, cv);
//
// dbWrite.close();
}
public void deleteData() {
Db db = new Db(MainActivity.this);
SQLiteDatabase dbWrite = db.getWritableDatabase();
dbWrite.delete("user2",null,new String[]{});
dbWrite.close();
}
public void refleshListView() {
Db db = new Db(MainActivity.this);
SQLiteDatabase dbRead = db.getReadableDatabase();
Cursor c = dbRead.query("user2", null, null, null, null, null, null);
mAdapter = new SimpleCursorAdapter(MainActivity.this, R.layout.user_info, c,
new String[]{"_id","name","sex"}, new int[]{R.id._id,R.id._name,R.id._sex});
listView.setAdapter(mAdapter);
dbRead.close();
}
}
user_info.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<TextView
android:id="@+id/_id"
android:textSize="20sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/_name"
android:textSize="20sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/_sex"
android:textSize="20sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content" /> </LinearLayout>
activity_main.xml
<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"> <Button
android:id="@+id/btn_add"
android:text="Add"
android:textSize="20sp"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<Button
android:id="@+id/btn_delete"
android:text="Delete"
android:textSize="20sp"
android:layout_width="match_parent"
android:layout_height="wrap_content" /> <ListView
android:id="@+id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"/> <Button
android:id="@+id/btn_back"
android:text="确定"
android:textSize="20sp"
android:layout_width="match_parent"
android:layout_height="wrap_content" /> <EditText
android:id="@+id/et_id"
android:visibility="gone"
android:layout_width="match_parent"
android:layout_height="40dp" />
<EditText
android:id="@+id/et_name"
android:visibility="gone"
android:layout_width="match_parent"
android:layout_height="40dp" />
<EditText
android:id="@+id/et_sex"
android:visibility="gone"
android:layout_width="match_parent"
android:layout_height="40dp" />
</LinearLayout>