Android 在Activity中对SQLite的操作

时间：2022-09-03 21:25:56

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;

        }

    }

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