Android之搜索框+含搜索历史记录

需求背景

今天在讨论群里，发现有多位童鞋们问到了这个问题，于是乎，产生了撸个轮子玩玩！这也是我第一次以这样方式玩简书，希望能帮助童鞋们解决实际中的问题，这才是重点！

知识要点梳理

1.使用Android自带的SQLiteOpenHelper
2.数据库的增删改查
3.sql 语句的编写

下面开始开车啦，老司机们赶紧上车哦！！哈哈。。。

1.撸个页面

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.yhx.app.MainActivity">


    <RelativeLayout
        android:textColor="@color/gray"
        android:textSize="14sp"
        android:layout_marginTop="10dp"
        android:layout_width="match_parent"
        android:layout_height="45dp">


        <Button
            android:id="@+id/btn_serarch"
            android:layout_width="80dp"
            android:layout_height="match_parent"
            android:layout_alignParentRight="true"
            android:hint="搜索"/>

        <EditText
            android:id="@+id/et_search"
            android:hint="输入内容"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_toLeftOf="@id/btn_serarch"/>

    </RelativeLayout>



    <RelativeLayout
        android:padding="10dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">


        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="历史记录"/>


        <TextView
            android:id="@+id/tv_deleteAll"
            android:layout_alignParentRight="true"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="删除历史记录"/>

    </RelativeLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/mRecyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="10dp">

    </android.support.v7.widget.RecyclerView>


</LinearLayout>

2.使用Android自带的SQLiteOpenHelper来创建表数据

/**
 * Created by yi.huangxing on 17/12/13.类描述:
 */

public class RecordSQLiteOpenHelper  extends SQLiteOpenHelper{
    private static String name = "record.db";
    private static Integer version = 1;


    public RecordSQLiteOpenHelper(Context context) {
        super(context, name, null, version);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        //打开数据库，建立了一个叫records的表，里面只有一列name来存储历史记录：
        db.execSQL("create table records(id integer primary key autoincrement,name varchar(200))");

    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

    }
}

3.表数据建好了，当然就是数据库的增，删，改，查，啰,为了使代码可读性性强，来个Dao层吧，那就叫DbDao

注意了，代码中的注释都是关键点，容易出错的地方哦。。。

public class DbDao {

    private Context context;
    private RecordSQLiteOpenHelper helper;
    private SQLiteDatabase db;

    public DbDao(Context context) {
        this.context = context;
        init();
    }

    private void init() {

        //实例化数据库SQLiteOpenHelper子类对象
        helper = new RecordSQLiteOpenHelper(context);
        // 第一次进入时查询所有的历史记录
        queryData("");
    }

    public List<String> queryData(String tempName) {
        List<String> data = new ArrayList<>();
        //模糊搜索
        Cursor cursor = helper.getReadableDatabase().rawQuery(
                "select id as _id,name from records where name like '%" + tempName + "%' order by id desc ", null);

        while (cursor.moveToNext()) {
            //注意这里的name跟建表的name统一
            String name = cursor.getString(cursor.getColumnIndex("name"));
            data.add(name);
        }
        cursor.close();
        return data;

    }

    /**
     * 检查数据库中是否已经有该条记录
     *
     * @param tempName
     * @return
     */
    public boolean hasData(String tempName) {
        //从Record这个表里找到name=tempName的id
        Cursor cursor = helper.getReadableDatabase().rawQuery(
                "select id as _id,name from records where name =?", new String[]{tempName});
        //判断是否有下一个
        return cursor.moveToNext();
    }

    /**
     * 插入数据
     *
     * @param tempName
     */
    public void insertData(String tempName) {
        db = helper.getWritableDatabase();
        db.execSQL("insert into records(name) values('" + tempName + "')");
        db.close();
    }

    /**
     * 插入数据
     *
     * @param name
     * @return
     */

    public int delete(String name) {
        // 获取数据
        SQLiteDatabase db = helper.getWritableDatabase();
        // 执行SQL
        int delete = db.delete("records", " name=?", new String[]{name});
        // 关闭数据库连接
        db.close();
        return delete;
    }

    /**
     * 清空数据
     */
    public void deleteData() {
        db = helper.getWritableDatabase();
        db.execSQL("delete from records");
        db.close();
    }
}

4.如何使用？

public class MainActivity extends AppCompatActivity {
    private Button mbtn_serarch;
    private EditText met_search;
    private RecyclerView mRecyclerView;
    private TextView mtv_deleteAll;
    private  SeachRecordAdapter mAdapter;

    private DbDao mDbDao;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initViews();
    }

    private void initViews() {
        mDbDao =new DbDao(this);
        mbtn_serarch = (Button) findViewById(R.id.btn_serarch);
        met_search = (EditText) findViewById(R.id.et_search);
        mtv_deleteAll = (TextView) findViewById(R.id.tv_deleteAll);
        mtv_deleteAll.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mDbDao.deleteData();
                mAdapter.updata(mDbDao.queryData(""));
            }
        });
        mRecyclerView = (RecyclerView) findViewById(R.id.mRecyclerView);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
        mAdapter =new SeachRecordAdapter(mDbDao.queryData(""),this);
        mAdapter.setRvItemOnclickListener(new BaseRecycleAdapter.RvItemOnclickListener() {
            @Override
            public void RvItemOnclick(int position) {
                mDbDao.delete(mDbDao.queryData("").get(position));

                mAdapter.updata(mDbDao.queryData(""));
            }
        });
        mRecyclerView.setAdapter(mAdapter);
        //事件监听
        mbtn_serarch.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                if (met_search.getText().toString().trim().length() != 0){
                    boolean hasData = mDbDao.hasData(met_search.getText().toString().trim());
                    if (!hasData){
                        mDbDao.insertData(met_search.getText().toString().trim());
                    }else {
                        Toast.makeText(MainActivity.this, "该内容已在历史记录中", Toast.LENGTH_SHORT).show();
                    }

                    //
                    mAdapter.updata(mDbDao.queryData(""));

                }else {
                    Toast.makeText(MainActivity.this, "请输入内容", Toast.LENGTH_SHORT).show();
                }

            }
        });
    }

}

5.demo中我使用了baseAdapter, 一并撸上吧

/**
 * Created by yi.huangxing on 17/12/13.类描述:
 */

public  abstract  class BaseRecycleAdapter  <T> extends RecyclerView.Adapter<BaseRecycleAdapter.BaseViewHolder>{

    protected List<T> datas;
    protected Context mContext;

    public BaseRecycleAdapter(List<T> datas,Context mContext) {
        this.datas = datas;
        this.mContext =mContext;
    }

    // 头部控件
    private View mHeaderView;

    // 底部控件
    private View mFooterView;


    // item 的三种类型
    public static final int ITEM_TYPE_NORMAL = 0X1111; // 正常的item类型
    public static final int ITEM_TYPE_HEADER = 0X1112; // header
    public static final int ITEM_TYPE_FOOTER = 0X1113; // footer


    private boolean isHasHeader = false;

    private boolean isHasFooter = false;

    @Override
    public BaseViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        if(viewType==ITEM_TYPE_FOOTER){
            // 如果是底部类型，返回底部视图
            return new BaseViewHolder(mFooterView);
        }

        if(viewType==ITEM_TYPE_HEADER){
            return new BaseViewHolder(mHeaderView);
        }
        View view = LayoutInflater.from(parent.getContext()).inflate(getLayoutId(),parent,false);
        return new BaseViewHolder(view);
    }

    @Override
    public void onBindViewHolder(BaseRecycleAdapter.BaseViewHolder holder, final int position) {

        if(isHasHeader&&isHasFooter){
            // 有头布局和底部时，向前便宜一个，且最后一个不能绑定数据
            if(position==0 ||position==datas.size()+1){
                return;
            }
            bindData(holder,position-1);
        }

        if(position!=0&&isHasHeader&&!isHasFooter){
            // 有顶部，但没有底部
            bindData(holder,position-1);
        }

        if(!isHasHeader&&isHasFooter){
            // 没有顶部，但有底部
            if(position==datas.size()){
                return;
            }
            bindData(holder,position);
        }

        if(!isHasHeader&&!isHasFooter){
            // 没有顶部，没有底部
            bindData(holder,position);
        }

    }

    /**
     * 添加头部视图
     * @param header
     */
    public void setHeaderView(View header){
        this.mHeaderView = header;
        isHasHeader = true;
        notifyDataSetChanged();
    }

    /**
     * 添加底部视图
     * @param footer
     */
    public void setFooterView(View footer){
        this.mFooterView = footer;
        isHasFooter = true;
        notifyDataSetChanged();
    }



    @Override
    public int getItemViewType(int position) {

        // 根据索引获取当前View的类型，以达到复用的目的

        // 根据位置的索引，获取当前position的类型
        if(isHasHeader&&position==0){
            return ITEM_TYPE_HEADER;
        }
        if(isHasHeader&&isHasFooter&&position==datas.size()+1){
            // 有头部和底部时，最后底部的应该等于size+!
            return ITEM_TYPE_FOOTER;
        }else if(!isHasHeader&&isHasFooter&&position==datas.size()){
            // 没有头部，有底部，底部索引为size
            return ITEM_TYPE_FOOTER;
        }
        return ITEM_TYPE_NORMAL;
    }

    /**
     * 刷新数据
     * @param datas
     */
    public void refresh(List<T> datas){
        this.datas.clear();
        this.datas.addAll(datas);
        notifyDataSetChanged();
    }

    /**
     *      刷新数据
     * @param data
     */
    public   void updata(List<T> data){
        this.datas=data;
        notifyDataSetChanged();
    }

    /**
     * 添加数据
     * @param datas
     */
    public void addData(List<T> datas){
        this.datas.addAll(datas);
        notifyDataSetChanged();
    }
    /**
     * 移除数据
     *
     * @param position
     */
    public void remove(int position) {
        if (position >= 0 && position < datas.size()) {
            datas.remove(position);
            notifyDataSetChanged();
        }
    }


    /**
     *  绑定数据
     * @param holder  具体的viewHolder
     * @param position  对应的索引
     */
    protected abstract void bindData(BaseViewHolder holder, int position);



    @Override
    public int getItemCount() {
        int size =  datas.size();
        if(isHasFooter)
            size ++;
        if(isHasHeader)
            size++;
        return size;
    }




    /**
     * 封装ViewHolder ,子类可以直接使用
     */
    public class BaseViewHolder extends  RecyclerView.ViewHolder{


        private Map<Integer, View> mViewMap;

        public BaseViewHolder(View itemView) {
            super(itemView);
            mViewMap = new HashMap<>();
        }

        /**
         * 获取设置的view
         * @param id
         * @return
         */
        public View getView(int id) {
            View view = mViewMap.get(id);
            if (view == null) {
                view = itemView.findViewById(id);
                mViewMap.put(id, view);
            }
            return view;
        }
    }

    /**
     * 获取子item
     * @return
     */
    public abstract int getLayoutId();



    /**
     * 设置文本属性
     * @param view
     * @param text
     */
    public void setItemText(View view,String text){
        if(view instanceof TextView){
            ((TextView) view).setText(text);
        }
    }


    public RvItemOnclickListener getRvItemOnclickListener() {
        return mRvItemOnclickListener;
    }

    public void setRvItemOnclickListener(RvItemOnclickListener rvItemOnclickListener) {
        mRvItemOnclickListener = rvItemOnclickListener;
    }

    protected     RvItemOnclickListener mRvItemOnclickListener;


    public interface  RvItemOnclickListener{

        void RvItemOnclick(int position);
    }



    /**
     *   这个方法很重要的
     * @param holder
     */
//
//    @Override
//    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
//        super.onAttachedToRecyclerView(recyclerView);
//
//        RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();
//        if(manager instanceof GridLayoutManager) {
//            final GridLayoutManager gridManager = ((GridLayoutManager) manager);
//            gridManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
//                @Override
//                public int getSpanSize(int position) {
//                    return getItemViewType(position) == TYPE_HEADER
//                           ? gridManager.getSpanCount() : 1;
//                }
//            });
//        }
//    }

}