<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="20dp">
<Button
android:id="@+id/btn_one"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:text="按钮1" />
<Button
android:id="@+id/btn_two"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="260dp"
android:text="按钮2" />
<Button
android:id="@+id/btn_three"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@id/btn_two"
android:layout_marginBottom="100dp"
android:layout_toRightOf="@id/btn_two"
android:text="按钮3" />
</RelativeLayout>
隐式
这道题考的是查询,也可能考其他的功能 (增删改查)
@Override
public void onClick(View v) {
String name, phone;
SQLiteDatabase db;
ContentValues values;
switch (v.getId()) {
case R.id.btn_query: //查询数据
db = myHelper.getReadableDatabase();
Cursor cursor = db.query("information", null, null, null, null,
null, null);
if (cursor.getCount() == 0) {
mTvShow.setText("");
Toast.makeText(this, "没有数据", Toast.LENGTH_SHORT).show();
} else {
cursor.moveToFirst();
mTvShow.setText("Name : " + cursor.getString(1) +
" ;Tel : " + cursor.getString(2));
}
while (cursor.moveToNext()) {
mTvShow.append("\n" + "Name : " + cursor.getString(1) +
" ;Tel : " + cursor.getString(2));
}
cursor.close();
db.close();
break;
case R.id.btn_add: //添加数据
name = mEtName.getText().toString();
phone = mEtPhone.getText().toString();
db = myHelper.getWritableDatabase();//获取可读写SQLiteDatabse对象
values = new ContentValues(); //创建ContentValues对象
values.put("name", name); //将数据添加到ContentValues对象
values.put("phone", phone);
db.insert("information", null, values);
Toast.makeText(this, "信息已添加", Toast.LENGTH_SHORT).show();
db.close();
break;
case R.id.btn_update: //修改数据
db = myHelper.getWritableDatabase();
values = new ContentValues(); // 要修改的数据
values.put("phone", phone = mEtPhone.getText().toString());
db.update("information", values, "name=?",
new String[]{mEtName.getText().toString()}); // 更新并得到行数
Toast.makeText(this, "信息已修改", Toast.LENGTH_SHORT).show();
db.close();
break;
case R.id.btn_delete: //删除数据
db = myHelper.getWritableDatabase();
db.delete("information", null, null);
Toast.makeText(this, "信息已删除", Toast.LENGTH_SHORT).show();
mTvShow.setText("");
db.close();
break;
}
}