Android 在Activity中对SQLite的操作

注册

 

package com.scme.ui;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;
import android.widget.Toast;

import com.scme.bean.Students;
import com.scme.db.DBHelper;

public class RegActivity extends Activity implements OnClickListener {

    private EditText et_Name, et_Pwd, et_Age;
    private Button bt_Save, bt_Clear;
    private DBHelper dao;
    private RadioGroup rg_sex;
    private RadioButton rg_nan, rg_nv;
    private String sex = "";

    private void init() {

        et_Name = (EditText) findViewById(R.id.et_Name);
        et_Pwd = (EditText) findViewById(R.id.et_Pwd);
        et_Age = (EditText) findViewById(R.id.et_Age);
        bt_Save = (Button) findViewById(R.id.bt_Save);
        bt_Clear = (Button) findViewById(R.id.bt_Clear);
        rg_sex = (RadioGroup) findViewById(R.id.rg_sex);
        rg_nan = (RadioButton) findViewById(R.id.rg_nan);
        rg_nv = (RadioButton) findViewById(R.id.rg_nv);
        dao = new DBHelper(this, null, null, 1);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.reg_activity);
        init();
        bt_Save.setOnClickListener(this);
        bt_Clear.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.bt_Save:
            String name = et_Name.getText().toString().trim();
            String pwd = et_Pwd.getText().toString().trim();
            rg_sex.setOnCheckedChangeListener(new OnCheckedChangeListener() {
                public void onCheckedChanged(RadioGroup arg0, int arg1) {
                    if (arg1 == R.id.rg_nan) {
                        sex = "男";
                    }
                    if(arg1 == R.id.rg_nv){
                        sex = "女";
                    }
                }
            });
            
            int age = Integer.parseInt(et_Age.getText().toString().trim());
            if (name.equals("")) {
                Toast.makeText(RegActivity.this, "姓名不能为空", 1000).show();
                return;
            }
            if (pwd.equals("")) {
                Toast.makeText(RegActivity.this, "密码不能为空", 1000).show();
                return;
            }
            if (sex.equals("")) {
                Toast.makeText(RegActivity.this, "性别不能为空", 1000).show();
                return;
            }
            //添加联系人
            Students stu = new Students();
            stu.setStuName(name);
            stu.setStuPwd(pwd);
            stu.setStuSex(sex);
            stu.setStuAge(age);
            dao.addStu(stu);
            Toast.makeText(RegActivity.this, "添加联系人成功", 1000).show();
            Intent intent = new Intent(RegActivity.this, LoginActivity.class);
            startActivity(intent);
            finish();
            break;

        case R.id.bt_Clear:
            // 取消注册
            finish();
            break;
        }
    }

}

 

添加

 

package com.scme.ui;

import com.scme.bean.Tongxunlu;
import com.scme.db.DBHelper;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class AddActivity extends Activity implements OnClickListener {
    
    private EditText add_txl_etName,add_txl_etPhone,add_txl_etEmail,add_txl_etAddr;
    
    private Button add_txl_btSave,add_txl_btClear;
    
    private DBHelper dao;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.add_activity);
        dao = new DBHelper(this, null, null, 1);
        
        add_txl_etName = (EditText) findViewById(R.id.add_txl_etName);
        add_txl_etPhone = (EditText) findViewById(R.id.add_txl_etPhone);
        add_txl_etEmail = (EditText) findViewById(R.id.add_txl_etEmail);
        add_txl_etAddr = (EditText) findViewById(R.id.add_txl_etAddr);
        
        add_txl_btSave = (Button) findViewById(R.id.add_txl_btSave);
        add_txl_btClear = (Button) findViewById(R.id.add_txl_btClear);
        add_txl_btSave.setOnClickListener(this);
        add_txl_btClear.setOnClickListener(this);
        
    }
    

    @Override
    public void onClick(View v) {
        String name = add_txl_etName.getText().toString().trim();
        String phone = add_txl_etPhone.getText().toString().trim();
        String email = add_txl_etEmail.getText().toString().trim();
        String addr = add_txl_etAddr.getText().toString().trim();
        
        
        if(v.getId() == R.id.add_txl_btClear){
            finish();
        }else if(v.getId() == R.id.add_txl_btSave){
            if(name.equals("")){
                Toast.makeText(AddActivity.this, "联系人姓名不能为空", 1000).show();
                return ;
            }if(phone.equals("")){
                Toast.makeText(AddActivity.this, "电话号码不能为空", 1000).show();
                return ;
            }
            
            //添加联系人
            Tongxunlu txl = new Tongxunlu();
            txl.setTxlName(name);
            txl.setTxlPhone(phone);
            txl.setTxlEmail(email);
            txl.setTxlAddr(addr);
            dao.addTxl(txl);
            Toast.makeText(AddActivity.this, "添加联系人成功", 1000).show();
            Intent intent = new Intent(AddActivity.this, MainActivity.class);
            startActivity(intent);
            finish();
            
            
        }
        
        
    }
}

 

 

登录

package com.scme.ui;

import com.scme.db.DBHelper;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class LoginActivity extends Activity implements OnClickListener {

    private EditText et_Name, et_Pwd;
    private Button bt_login, bt_Reg;
    private DBHelper dao;

    private void init() {

        et_Name = (EditText) findViewById(R.id.et_Name);
        et_Pwd = (EditText) findViewById(R.id.et_Pwd);
        bt_login = (Button) findViewById(R.id.bt_login);
        bt_Reg = (Button) findViewById(R.id.bt_Reg);
        dao = new DBHelper(this, null, null, 1);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login_activity);
        init();
        bt_login.setOnClickListener(this);
        bt_Reg.setOnClickListener(this);

    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.bt_login:
            String name = et_Name.getText().toString().trim();
            String pwd = et_Pwd.getText().toString().trim();
            boolean a = dao.login(name, pwd);
            if (a) {
                Toast.makeText(LoginActivity.this, "登陆成功", 1000).show();
                Intent intent = new Intent(LoginActivity.this,
                        MainActivity.class);
                startActivity(intent);
            } else {
                Toast.makeText(LoginActivity.this, "登陆失败", 1000).show();
            }
            break;
        case R.id.bt_Reg:
            Intent intent = new Intent(LoginActivity.this, RegActivity.class);
            startActivity(intent);
            break;
        }
    }
}

 

 

显示

 

package com.scme.ui;

import java.util.List;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;

import com.scme.bean.Tongxunlu;
import com.scme.db.DBHelper;

public class MainActivity extends Activity {

    private EditText et_query;
    private MyAdapter a;
    private DBHelper dao;
    private ListView lv_info;
    private List<Tongxunlu> lists;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_activity);
        // 获得显示页面的查询文本框
        et_query = (EditText) findViewById(R.id.et_query);
        // 获得ListView的id
        lv_info = (ListView) findViewById(R.id.lvTXL);
        // 实例化DBHelper
        dao = new DBHelper(this, null, null, 0);
        // 调用查询方法
        lists = dao.queryName(null);
        // 实例化适配器
        a = new MyAdapter();
        // 将适配器放入ListView中
        lv_info.setAdapter(a);
        // 当在查询文本框中输入数据是触发查询事件
        et_query.addTextChangedListener(new TextWatcher() {
            // 内容改变后触发
            public void onTextChanged(CharSequence s, int start, int before,
                    int count) {
                lists = dao.queryName(s.toString());
                // 当ListView中的数据改变后让适配器自动更新
                a = new MyAdapter();
                // 将适配器放入ListView中
                lv_info.setAdapter(a);
            }

            public void beforeTextChanged(CharSequence s, int start, int count,
                    int after) {
            }

            public void afterTextChanged(Editable s) {
            }
        });

    }
    
    /**
     * 返回页面重新查询
     */
    protected void onRestart() {
        super.onRestart();
        lists = dao.queryName(null);
        a = new MyAdapter();
        // 将适配器放入ListView中
        lv_info.setAdapter(a);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        menu.add(1, 1, 1, "新增联系人");
        menu.add(1, 2, 2, "退出");
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // 判断点击的菜单的ID
        if (item.getItemId() == 1) {
            Intent intent = new Intent(MainActivity.this, AddActivity.class);
            // startActivity(intent);
            startActivityForResult(intent, 1);
        } else {
            finish();
        }
        return super.onOptionsItemSelected(item);
    }

    public class MyAdapter extends BaseAdapter {

        public int getCount() {
            return lists.size();
        }

        public Object getItem(int arg0) {
            return null;
        }

        public long getItemId(int arg0) {
            return 0;
        }

        public View getView(int i, View view, ViewGroup arg2) {
            View v = null;
            ViewHolder vh;
            final Tongxunlu txl = lists.get(i);
            if (view == null) {
                // 说明当前这一行不是重用的
                // 加载行布局文件，产生具体的一行
                v = getLayoutInflater().inflate(R.layout.list_view, null);
                // 创建存储一行控件的对象
                vh = new ViewHolder();
                vh.name = (TextView) v.findViewById(R.id.te_lx_name);
                vh.phone = (TextView) v.findViewById(R.id.te_lx_phone);
                vh.update = (Button) v.findViewById(R.id.list_item_btnUpdate);
                vh.del = (Button) v.findViewById(R.id.list_item_btnDel);

                v.setTag(vh);
                vh.del.setOnClickListener(new OnClickListener() {
                    public void onClick(View arg0) {
                        dao.delTxl(txl.get_id());
                        lists = dao.queryName(null);
                        a = new MyAdapter();
                        // 将适配器放入ListView中
                        lv_info.setAdapter(a);
                    }
                });
            } else {
                v = view;
                // 取出隐藏在行中的Tag--取出隐藏在这一行中的vh控件缓存对象
                vh = (ViewHolder) view.getTag();

            }
            // 从ViewHolder缓存的控件中改变控件的值
            // 这里主要是避免多次强制转化目标对象而造成的资源浪费
            vh.name.setText(txl.getTxlName());
            vh.phone.setText(txl.getTxlPhone());
            return v;
        }

        // 存储一行中的控件（缓存作用）---避免多次强转每行的控件
        class ViewHolder {
            TextView name;
            TextView phone;
            Button update;
            Button del;
        }
    }
}

 

 ListView的优化

public class MyAdapter extends BaseAdapter {

        public int getCount() {
            return lists.size();
        }

        public Object getItem(int arg0) {
            return null;
        }

        public long getItemId(int arg0) {
            return 0;
        }

        public View getView(int i, View view, ViewGroup arg2) {
            View v = null;
            ViewHolder vh;
            final Tongxunlu txl = lists.get(i);
            if (view == null) {
                // 说明当前这一行不是重用的
                // 加载行布局文件，产生具体的一行
                v = getLayoutInflater().inflate(R.layout.list_view, null);
                // 创建存储一行控件的对象
                vh = new ViewHolder();
                vh.name = (TextView) v.findViewById(R.id.te_lx_name);
                vh.phone = (TextView) v.findViewById(R.id.te_lx_phone);
                vh.update = (Button) v.findViewById(R.id.list_item_btnUpdate);
                vh.del = (Button) v.findViewById(R.id.list_item_btnDel);

                v.setTag(vh);
                vh.del.setOnClickListener(new OnClickListener() {
                    public void onClick(View arg0) {
                        dao.delTxl(txl.get_id());
                        lists = dao.queryName(null);
                        a = new MyAdapter();
                        // 将适配器放入ListView中
                        lv_info.setAdapter(a);
                    }
                });
            } else {
                v = view;
                // 取出隐藏在行中的Tag--取出隐藏在这一行中的vh控件缓存对象
                vh = (ViewHolder) view.getTag();

            }
            // 从ViewHolder缓存的控件中改变控件的值
            // 这里主要是避免多次强制转化目标对象而造成的资源浪费
            vh.name.setText(txl.getTxlName());
            vh.phone.setText(txl.getTxlPhone());
            return v;
        }

        // 存储一行中的控件（缓存作用）---避免多次强转每行的控件
        class ViewHolder {
            TextView name;
            TextView phone;
            Button update;
            Button del;
        }
    }