package com.example.week3_1.dao;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import com.example.week3_1.adapter.MyAdapter;
import com.example.week3_1.adapter.MyHelper;
import java.util.List;
public class MyDao {
private final MyHelper myHelper;
private final SQLiteDatabase database;
public MyDao(Context context){
myHelper = new MyHelper(context);
database = myHelper.getWritableDatabase();
}
//查询
public Cursor select(){
Cursor query = database.query("student", null, null, null, null, null, null);
return query;
}
//添加
public void insert(String s){
ContentValues values = new ContentValues();
values.put("name",s);
database.insert("student",null,values);
}
//删除
public void del(String s){
database.delete("student","name=?",new String[]{s});
}
//修改
public void update(String s,String beforeData){
ContentValues values = new ContentValues();
values.put("name",s);
database.update("student", values, "name=?", new String[]{beforeData});
}
}
MainActivity页面
package com.example.week3_1;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import com.example.week3_1.dao.MyDao;
public class Main2Activity extends AppCompatActivity implements View.OnClickListener {
private EditText name;
private EditText pwd;
private Button tianjia;
private MyDao dao;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
dao = new MyDao(Main2Activity.this);
initView();
}
private void initView() {
name = (EditText) findViewById(R.id.name);
pwd = (EditText) findViewById(R.id.pwd);
tianjia = (Button) findViewById(R.id.tianjia);
tianjia.setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.tianjia:
dao.insert(name.getText().toString());
finish();
break;
}
}
private void submit() {
// validate
String nameString = name.getText().toString().trim();
if (TextUtils.isEmpty(nameString)) {
Toast.makeText(this, "nameString不能为空", Toast.LENGTH_SHORT).show();
return;
}
String pwdString = pwd.getText().toString().trim();
if (TextUtils.isEmpty(pwdString)) {
Toast.makeText(this, "pwdString不能为空", Toast.LENGTH_SHORT).show();
return;
}
// TODO validate success, do something
}
}