android142 360 分页加载

dao:

package com.itheima.mobileguard.db.dao;

import java.util.ArrayList;
import java.util.List;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.SystemClock;

import com.itheima.mobileguard.db.BlackNumberDBOpenHelper;
import com.itheima.mobileguard.domain.BlackNumberInfo;

/**
 * 黑名单数据库的增删改查工具类
 *
 * @author Administrator
 *
 */
public class BlackNumberDao {
    private BlackNumberDBOpenHelper helper;

    public BlackNumberDao(Context context) {
        helper = new BlackNumberDBOpenHelper(context);
    }

    /**
     * 添加黑名单号码
     *
     * @param number
     *            号码
     * @param mode
     *            拦截模式
     * @return 是否添加成功
     */
    public boolean add(String number, String mode) {
        // 获取到可写的数据库
        SQLiteDatabase db = helper.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put("number", number);
        values.put("mode", mode);
        long rowid = db.insert("blackinfo", null, values);
        if (rowid == -1) {
            return false;
        } else {
            return true;
        }
    }

    /**
     * 删除黑名单号码
     *
     * @param number
     *            号码
     * @return 是否删除成功
     */
    public boolean delete(String number) {
        // 获取到可写的数据库
        SQLiteDatabase db = helper.getWritableDatabase();
        int rownumber = db.delete("blackinfo", "number=?",
                new String[] { number });
        if (rownumber == 0) {
            return false;
        } else {
            return true;
        }
    }

    /**
     * 修改黑名单号码的拦截模式
     *
     * @param number
     *            号码
     * @param newmode
     *            新的拦截模式
     * @return 是否修改成功
     */
    public boolean changeBlockMode(String number, String newmode) {
        // 获取到可写的数据库
        SQLiteDatabase db = helper.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put("mode", newmode);
        int rownumber =db.update("blackinfo", values, "number=?", new String[]{number});
        if (rownumber == 0) {
            return false;
        } else {
            return true;
        }
    }
    /**
     * 返回一个黑名单号码拦截模式
     * @param number 要查询的黑名单号码
     * @return 0不是黑名单号码不拦截 1全部拦截 2短信拦截 3电话拦截
     */
    public String findBlockMode(String number){
        String mode = "0";
        // 获取到可读的数据库
        SQLiteDatabase db = helper.getReadableDatabase();
        Cursor cursor = db.query("blackinfo", new String[]{"mode"}, "number=?", new String[]{number}, null, null, null);
        if(cursor.moveToNext()){
            mode = cursor.getString(0);
        }
        cursor.close();
        db.close();
        return mode;
    }

    /**
     * 查询全部的黑名单号码
     */
    public List<BlackNumberInfo> findAll(){
        // 得到可读的数据库
        SQLiteDatabase db = helper.getReadableDatabase();
        Cursor cursor = db.query("blackinfo", new String[]{"number","mode"}, null, null, null, null, null);
        List<BlackNumberInfo> blackNumberInfos = new ArrayList<BlackNumberInfo>();
        while(cursor.moveToNext()){
            BlackNumberInfo info = new BlackNumberInfo();
            String number = cursor.getString(0);
            String mode = cursor.getString(1);
            info.setMode(mode);
            info.setNumber(number);
            blackNumberInfos.add(info);
        }
        cursor.close();
        db.close();
        SystemClock.sleep(3000);
        return blackNumberInfos;
    }

    /**
     * 分页查询数据库的记录
     * @param pagenumber 第几页，页码 从第0页开始
     * @param pagesize   每一个页面的大小
     */
    public List<BlackNumberInfo> findPart(int pagenumber,int pagesize){
        // 得到可读的数据库
        SQLiteDatabase db = helper.getReadableDatabase();
        Cursor cursor = db.rawQuery("select number,mode from blackinfo limit ? offset ?", new String[]{String.valueOf(pagesize),
                String.valueOf(pagesize*pagenumber)
        });
        List<BlackNumberInfo> blackNumberInfos = new ArrayList<BlackNumberInfo>();
        while(cursor.moveToNext()){
            BlackNumberInfo info = new BlackNumberInfo();
            String number = cursor.getString(0);
            String mode = cursor.getString(1);
            info.setMode(mode);
            info.setNumber(number);
            blackNumberInfos.add(info);
        }
        cursor.close();
        db.close();
        SystemClock.sleep(30);
        return blackNumberInfos;
    }

    /**
     * 分批加载数据
     * @param startIndex 从哪个位置开始加载数据
     * @param maxCount   最多加载几条数据
     */
    public List<BlackNumberInfo> findPart2(int startIndex,int maxCount){
        // 得到可读的数据库
        SQLiteDatabase db = helper.getReadableDatabase();
        Cursor cursor = db.rawQuery("select number,mode from blackinfo order by _id desc limit ? offset ?", new String[]{String.valueOf(maxCount),
                String.valueOf(startIndex)
        });
        List<BlackNumberInfo> blackNumberInfos = new ArrayList<BlackNumberInfo>();
        while(cursor.moveToNext()){
            BlackNumberInfo info = new BlackNumberInfo();
            String number = cursor.getString(0);
            String mode = cursor.getString(1);
            info.setMode(mode);
            info.setNumber(number);
            blackNumberInfos.add(info);
        }
        cursor.close();
        db.close();
        SystemClock.sleep(30);
        return blackNumberInfos;
    }

    /**
     * 获取数据库的总条目个数
     * @param pagenumber 第几页，页码 从第0页开始
     * @param pagesize   每一个页面的大小
     */
    public int getTotalNumber(){
        // 得到可读的数据库
        SQLiteDatabase db = helper.getReadableDatabase();
        Cursor cursor = db.rawQuery("select count(*) from blackinfo",null);
        cursor.moveToNext();
        int count = cursor.getInt(0);
        cursor.close();
        db.close();
        return count;
    }
}

选择页码跳页加载 activity:

package com.itheima.mobileguard.activities;

import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.text.TextUtils;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import com.itheima.mobileguard.R;
import com.itheima.mobileguard.db.dao.BlackNumberDao;
import com.itheima.mobileguard.domain.BlackNumberInfo;

public class CallSmsSafeActivity2 extends Activity {
    private ListView lv_callsms_safe;
    private LinearLayout ll_add_number_tips;
    private LinearLayout ll_loading;
    /**
     * 页面输入框
     */
    private EditText et_page_number;

    /**
     * 页码信息
     */
    private TextView tv_page_info;

    /**
     * 页面大小
     */
    private static final int pageSize = 20;
    /**
     * 当前页码号
     */
    private int curentPgeNumber = 0;
    /**
     * 一共有多少页
     */
    private int totalPage = 0;

    private BlackNumberDao dao;
    private List<BlackNumberInfo> infos;
    /**
     * 消息处理器
     */
    private Handler handler = new Handler(){
        public void handleMessage(android.os.Message msg) {
            ll_loading.setVisibility(View.INVISIBLE);
            if (infos.size() == 0) {
                // 没有数据，设置添加数据的提醒
                ll_add_number_tips.setVisibility(View.VISIBLE);
            } else {
                lv_callsms_safe.setAdapter(new CallSmsSafeAdapter());
            }
        };
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        initUI();
        fillData();
    }

    /**
     * 填充数据
     */
    private void fillData() {
        dao = new BlackNumberDao(this);
        //数据库的总条目个数 /  每个页面最多显示多少条数据
        totalPage  =  dao.getTotalNumber()/pageSize;
        tv_page_info.setText(curentPgeNumber+"/"+totalPage);
        //耗时的操作 逻辑应该放在子线程里面执行。
        ll_loading.setVisibility(View.VISIBLE);
        new Thread(){
            public void run() {
                infos = dao.findPart(curentPgeNumber, pageSize);
                handler.sendEmptyMessage(0);
            };
        }.start();
    }

    /**
     * 初始化ui的逻辑块
     */
    private void initUI() {
        setContentView(R.layout.activity_callsms_safe);
        ll_add_number_tips = (LinearLayout) findViewById(R.id.ll_add_number_tips);
        ll_loading = (LinearLayout) findViewById(R.id.ll_loading);
        lv_callsms_safe = (ListView) findViewById(R.id.lv_callsms_safe);
        et_page_number = (EditText) findViewById(R.id.et_page_number);
        tv_page_info = (TextView) findViewById(R.id.tv_page_info);
    }

    private class CallSmsSafeAdapter extends BaseAdapter {

        @Override
        public int getCount() {
            return infos.size();
        }

        //这个方法要被执行很多次， 有多个条目 就要执行多少次
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            System.out.println("getview:"+position);
            View view;
            ViewHolder holder;
            if (convertView == null) {
                view = View.inflate(CallSmsSafeActivity2.this,
                        R.layout.item_callsms, null);
                holder = new ViewHolder(); //减少子孩子查询的次数
                holder.tv_phone = (TextView) view
                        .findViewById(R.id.tv_item_phone);
                holder.tv_mode = (TextView) view.findViewById(R.id.tv_item_mode);
                //把孩子id的引用 存放在holder里面，设置给父亲 view
                view.setTag(holder);
            } else {
                view = convertView; //使用历史缓存view对象， 减少view对象被创建的次数
                holder = (ViewHolder) view.getTag();
            }

            BlackNumberInfo info = infos.get(position);
            holder.tv_phone.setText(info.getNumber());
            // 1 全部拦截 2 短信拦截 3 电话拦截
            String mode = info.getMode();
            if ("1".equals(mode)) {
                holder.tv_mode.setText("全部拦截");
            } else if ("2".equals(mode)) {
                holder.tv_mode.setText("短信拦截 ");
            } else if ("3".equals(mode)) {
                holder.tv_mode.setText("电话拦截 ");
            }
            return view;
        }

        @Override
        public Object getItem(int position) {
            return null;
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }
    }

    /**
     * 家庭组 view对象的容器
     * @author Administrator
     *
     */
    class ViewHolder{
        TextView tv_phone;
        TextView tv_mode;
    }

    /**
     * 上一页
     * @param view
     */
    public void prePage(View view){
        if(curentPgeNumber<=0){
            Toast.makeText(this, "已经是第一页", 0).show();
            return;
        }
        curentPgeNumber--;
        fillData();
    }

    /**
     * 下一页
     * @param view
     */
    public void nextPage(View view){
        if(curentPgeNumber>(totalPage-1)){
            Toast.makeText(this, "已经是最后一页", 0).show();
            return;
        }
        curentPgeNumber++;
        fillData();
    }

    /**
     * 跳转
     * @param view
     */
    public void jump(View view){
        String str_pagenumber = et_page_number.getText().toString().trim();
        if(TextUtils.isEmpty(str_pagenumber)){
            Toast.makeText(this, "请输入页面号", 0).show();
        }else{
            int number = Integer.parseInt(str_pagenumber);
            if(number>=0&&number<totalPage){
                curentPgeNumber=number;
                fillData();
            }else{
                Toast.makeText(this, "请输入正确的页面号", 0).show();
            }
        }
    }
}

没有页码滑动分批加载Activity：

package com.itheima.mobileguard.activities;

import java.util.List;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.os.Bundle;
import android.os.Handler;
import android.text.TextUtils;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.BaseAdapter;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import com.itheima.mobileguard.R;
import com.itheima.mobileguard.db.dao.BlackNumberDao;
import com.itheima.mobileguard.domain.BlackNumberInfo;

public class CallSmsSafeActivity extends Activity {
    private ListView lv_callsms_safe;
    private LinearLayout ll_add_number_tips;
    private LinearLayout ll_loading;

    private BlackNumberDao dao;
    private List<BlackNumberInfo> infos; // 代表就是当前界面的集合。

    private CallSmsSafeAdapter adapter;

    /**
     * 开始获取数据的位置
     */
    private int startIndex = 0;

    /**
     * 一次最多获取几条数据
     */
    private int maxCount = 20;

    private int totalCount = 0;

    /**
     * 消息处理器
     */
    private Handler handler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            ll_loading.setVisibility(View.INVISIBLE);
            if (infos.size() == 0) {
                // 没有数据，设置添加数据的提醒
                ll_add_number_tips.setVisibility(View.VISIBLE);
            } else {
                if (adapter == null) {
                    adapter = new CallSmsSafeAdapter();
                    lv_callsms_safe.setAdapter(adapter);
                } else {// 数据适配器是已经存在的。
                        // 因为数据适配器里面的数据 已经变化。刷新界面。
                    adapter.notifyDataSetChanged();
                }
            }
        };
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        initUI();
        fillData();
    }

    /**
     * 填充数据
     */
    private void fillData() {
        dao = new BlackNumberDao(this);
        totalCount = dao.getTotalNumber();
        // 数据库的总条目个数 / 每个页面最多显示多少条数据
        // 耗时的操作 逻辑应该放在子线程里面执行。
        ll_loading.setVisibility(View.VISIBLE);
        new Thread() {
            public void run() {
                if (infos == null) {
                    infos = dao.findPart2(startIndex, maxCount);
                } else {
                    // 集合里面原来有数据,新的数据应该放在旧的集合的后面。
                    infos.addAll(dao.findPart2(startIndex, maxCount));
                }
                handler.sendEmptyMessage(0);
            };
        }.start();
    }

    /**
     * 初始化ui的逻辑块
     */
    private void initUI() {
        setContentView(R.layout.activity_callsms_safe);
        ll_add_number_tips = (LinearLayout) findViewById(R.id.ll_add_number_tips);
        ll_loading = (LinearLayout) findViewById(R.id.ll_loading);
        lv_callsms_safe = (ListView) findViewById(R.id.lv_callsms_safe);

        lv_callsms_safe.setOnScrollListener(new OnScrollListener() {
            // 滚动状态发生变化调用的方法。
            // OnScrollListener.SCROLL_STATE_FLING 惯性滑动
            // OnScrollListener.SCROLL_STATE_TOUCH_SCROLL 触摸滑动
            // OnScrollListener.SCROLL_STATE_IDLE 静止
            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {
                switch (scrollState) {
                case OnScrollListener.SCROLL_STATE_IDLE: // 静止状态
                    // 判断是否是最后一个条目。
                    int lastPosition = lv_callsms_safe.getLastVisiblePosition();
                    System.out.println("最后一个可见条目的位置：" + lastPosition);
                    if (lastPosition == infos.size() - 1) { // //20条数据
                        // 加载下20条数据。 更改加载数据的开始位置
                        startIndex += maxCount;
                        if (startIndex >= totalCount) {//已经到达最后
                            Toast.makeText(getApplicationContext(),
                                    "没有更多的数据了。", 0).show();
                            return;
                        }
                        fillData();
                    }
                    break;
                }
            }

            // 只要listview发生滚动 就会调用下面的方法
            @Override
            public void onScroll(AbsListView view, int firstVisibleItem,
                    int visibleItemCount, int totalItemCount) {

            }
        });

    }

    private class CallSmsSafeAdapter extends BaseAdapter {

        @Override
        public int getCount() {
            return infos.size();
        }

        // 这个方法要被执行很多次， 有多个条目 就要执行多少次
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View view;
            ViewHolder holder;
            if (convertView == null) {
                view = View.inflate(CallSmsSafeActivity.this,
                        R.layout.item_callsms, null);
                holder = new ViewHolder(); // 减少子孩子查询的次数
                holder.tv_phone = (TextView) view
                        .findViewById(R.id.tv_item_phone);
                holder.tv_mode = (TextView) view
                        .findViewById(R.id.tv_item_mode);
                holder.iv_delete = (ImageView) view
                        .findViewById(R.id.iv_delete);
                // 把孩子id的引用 存放在holder里面，设置给父亲 view
                view.setTag(holder);
            } else {
                view = convertView; // 使用历史缓存view对象， 减少view对象被创建的次数
                holder = (ViewHolder) view.getTag();
            }

            final BlackNumberInfo info = infos.get(position);
            holder.iv_delete.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    String number = info.getNumber();
                    // 从数据库删除黑名单号码
                    boolean result = dao.delete(number);
                    if (result) {
                        Toast.makeText(getApplicationContext(), "删除成功", 0)
                                .show();
                        // 从界面ui里面删除信息
                        infos.remove(info);
                        // 通知界面刷新
                        adapter.notifyDataSetChanged();
                    } else {
                        Toast.makeText(getApplicationContext(), "删除失败", 0)
                                .show();
                    }
                }
            });
            holder.tv_phone.setText(info.getNumber());
            // 1 全部拦截 2 短信拦截 3 电话拦截
            String mode = info.getMode();
            if ("1".equals(mode)) {
                holder.tv_mode.setText("全部拦截");
            } else if ("2".equals(mode)) {
                holder.tv_mode.setText("短信拦截 ");
            } else if ("3".equals(mode)) {
                holder.tv_mode.setText("电话拦截 ");
            }
            return view;
        }

        @Override
        public Object getItem(int position) {
            return null;
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }
    }

    /**
     * 家庭组 view对象的容器
     *
     * @author Administrator
     *
     */
    class ViewHolder {
        TextView tv_phone;
        TextView tv_mode;
        ImageView iv_delete;
    }

    /**
     * 添加黑名单号码
     *
     * @param view
     */
    public void addBlackNumber(View view) {
        AlertDialog.Builder builder = new Builder(this);
        View dialogView = View.inflate(this, R.layout.dialog_add_blacknumber,
                null);
        final AlertDialog dialog = builder.create();
        final EditText et_black_number = (EditText) dialogView
                .findViewById(R.id.et_black_number);
        final CheckBox cb_phone = (CheckBox) dialogView
                .findViewById(R.id.cb_phone);
        final CheckBox cb_sms = (CheckBox) dialogView.findViewById(R.id.cb_sms);
        dialogView.findViewById(R.id.bt_cancel).setOnClickListener(
                new OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        dialog.dismiss();
                    }
                });
        dialogView.findViewById(R.id.bt_ok).setOnClickListener(
                new OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        String blackNumber = et_black_number.getText()
                                .toString().trim();
                        if (TextUtils.isEmpty(blackNumber)) {
                            Toast.makeText(getApplicationContext(), "号码不能为空", 1)
                                    .show();
                            return;
                        }
                        String mode = "0";
                        // 1 全部拦截 2 短信拦截 3 电话拦截
                        if (cb_phone.isChecked() && cb_sms.isChecked()) {
                            mode = "1";
                        } else if (cb_phone.isChecked()) {
                            mode = "3";
                        } else if (cb_sms.isChecked()) {
                            mode = "2";
                        } else {
                            Toast.makeText(getApplicationContext(), "请选择拦截模式",
                                    1).show();
                            return;
                        }
                        // 把数据添加到数据库
                        boolean result = dao.add(blackNumber, mode);
                        // 刷新界面。 把数据加入到infos集合里面。
                        if (result) {
                            BlackNumberInfo info = new BlackNumberInfo();
                            info.setMode(mode);
                            info.setNumber(blackNumber);
                            infos.add(0, info);// 界面的数据集合发生了变化。
                            // 通知界面刷新。
                            if (adapter != null) {
                                adapter.notifyDataSetChanged();
                            } else {
                                adapter = new CallSmsSafeAdapter();
                                lv_callsms_safe.setAdapter(adapter);
                            }
                        }

                        dialog.dismiss();
                    }
                });

        dialog.setView(dialogView, 0, 0, 0, 0);
        dialog.show();
    }

}