Android搜索功能的案例，本地保存搜索历史记录

同事负责开发的APP有一个搜索功能，并且需要显示搜索的历史记录，我闲暇之余帮她开发了这个功能，现把该页面抽取成一个demo分享给大家。

实现效果如图所示：

本案例实现起来很简单，所以可以直接拿来嵌入项目中使用，涉及到的知识点：
- 数据库的增删改查操作
- ListView和ScrollView的嵌套冲突解决
- 监听软键盘回车按钮设置为搜索按钮
- 使用TextWatcher( )实时筛选
- 已搜索的关键字再次搜索不重复添加到数据库
- 刚进入页面设置软键盘不因为EditText而自动弹出

---

代码

1. RecordSQLiteOpenHelper.java

package com.cwvs.microlife;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;public class RecordSQLiteOpenHelper extends SQLiteOpenHelper {    private static String name = "temp.db";    private static Integer version = 1;    public RecordSQLiteOpenHelper(Context context) {        super(context, name, null, version);    }    @Override    public void onCreate(SQLiteDatabase db) {        db.execSQL("create table records(id integer primary key autoincrement,name varchar(200))");    }    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {    }}

1. MainActivity.java

package com.cwvs.microlife;import java.util.Date;import android.app.Activity;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.graphics.drawable.Drawable;import android.os.Bundle;import android.text.Editable;import android.text.TextWatcher;import android.view.KeyEvent;import android.view.View;import android.view.Window;import android.view.inputmethod.InputMethodManager;import android.widget.AdapterView;import android.widget.BaseAdapter;import android.widget.CursorAdapter;import android.widget.EditText;import android.widget.SimpleCursorAdapter;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity {    private EditText et_search;    private TextView tv_tip;    private MyListView listView;    private TextView tv_clear;    private RecordSQLiteOpenHelper helper = new RecordSQLiteOpenHelper(this);;    private SQLiteDatabase db;    private BaseAdapter adapter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        requestWindowFeature(Window.FEATURE_NO_TITLE);        setContentView(R.layout.activity_main);        // 初始化控件        initView();        // 清空搜索历史        tv_clear.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                deleteData();                queryData("");            }        });        // 搜索框的键盘搜索键点击回调        et_search.setOnKeyListener(new View.OnKeyListener() {// 输入完后按键盘上的搜索键            public boolean onKey(View v, int keyCode, KeyEvent event) {                if (keyCode == KeyEvent.KEYCODE_ENTER && event.getAction() == KeyEvent.ACTION_DOWN) {// 修改回车键功能                    // 先隐藏键盘                    ((InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE)).hideSoftInputFromWindow(                            getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);                    // 按完搜索键后将当前查询的关键字保存起来,如果该关键字已经存在就不执行保存                    boolean hasData = hasData(et_search.getText().toString().trim());                    if (!hasData) {                        insertData(et_search.getText().toString().trim());                        queryData("");                    }                    // TODO 根据输入的内容模糊查询商品，并跳转到另一个界面，由你自己去实现                    Toast.makeText(MainActivity.this, "clicked!", Toast.LENGTH_SHORT).show();                }                return false;            }        });        // 搜索框的文本变化实时监听        et_search.addTextChangedListener(new TextWatcher() {            @Override            public void beforeTextChanged(CharSequence s, int start, int count, int after) {            }            @Override            public void onTextChanged(CharSequence s, int start, int before, int count) {            }            @Override            public void afterTextChanged(Editable s) {                if (s.toString().trim().length() == 0) {                    tv_tip.setText("搜索历史");                } else {                    tv_tip.setText("搜索结果");                }                String tempName = et_search.getText().toString();                // 根据tempName去模糊查询数据库中有没有数据                queryData(tempName);            }        });        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {            @Override            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {                TextView textView = (TextView) view.findViewById(android.R.id.text1);                String name = textView.getText().toString();                et_search.setText(name);                Toast.makeText(MainActivity.this, name, Toast.LENGTH_SHORT).show();                // TODO 获取到item上面的文字，根据该关键字跳转到另一个页面查询，由你自己去实现            }        });        // 插入数据，便于测试，否则第一次进入没有数据怎么测试呀？        Date date = new Date();        long time = date.getTime();        insertData("Leo" + time);        // 第一次进入查询所有的历史记录        queryData("");    }    /**     * 插入数据     */    private void insertData(String tempName) {        db = helper.getWritableDatabase();        db.execSQL("insert into records(name) values('" + tempName + "')");        db.close();    }    /**     * 模糊查询数据     */    private void queryData(String tempName) {        Cursor cursor = helper.getReadableDatabase().rawQuery(                "select id as _id,name from records where name like '%" + tempName + "%' order by id desc ", null);        // 创建adapter适配器对象        adapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, cursor, new String[] { "name" },                new int[] { android.R.id.text1 }, CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);        // 设置适配器        listView.setAdapter(adapter);        adapter.notifyDataSetChanged();    }    /**     * 检查数据库中是否已经有该条记录     */    private boolean hasData(String tempName) {        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();    }    /**     * 清空数据     */    private void deleteData() {        db = helper.getWritableDatabase();        db.execSQL("delete from records");        db.close();    }    private void initView() {        et_search = (EditText) findViewById(R.id.et_search);        tv_tip = (TextView) findViewById(R.id.tv_tip);        listView = (com.cwvs.microlife.MyListView) findViewById(R.id.listView);        tv_clear = (TextView) findViewById(R.id.tv_clear);        // 调整EditText左边的搜索按钮的大小        Drawable drawable = getResources().getDrawable(R.drawable.search);        drawable.setBounds(0, 0, 60, 60);// 第一0是距左边距离，第二0是距上边距离，60分别是长宽        et_search.setCompoundDrawables(drawable, null, null, null);// 只放左边    }}

1. MyListView.java

package com.cwvs.microlife;import android.content.Context;import android.util.AttributeSet;import android.widget.ListView;public class MyListView extends ListView {    public MyListView(Context context) {        super(context);    }    public MyListView(Context context, AttributeSet attrs) {        super(context, attrs);    }    public MyListView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,                MeasureSpec.AT_MOST);        super.onMeasure(widthMeasureSpec, expandSpec);    }}

1. activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:focusableInTouchMode="true"    android:orientation="vertical"    tools:context="${relativePackage}.${activityClass}">    <LinearLayout        android:layout_width="fill_parent"        android:layout_height="50dp"        android:background="#E54141"        android:orientation="horizontal"        android:paddingRight="16dp">        <ImageView            android:layout_width="45dp"            android:layout_height="45dp"            android:layout_gravity="center_vertical"            android:padding="10dp"            android:src="@drawable/back" />        <EditText            android:id="@+id/et_search"            android:layout_width="0dp"            android:layout_height="match_parent"            android:layout_weight="1"            android:background="@null"            android:drawableLeft="@drawable/search"            android:drawablePadding="8dp"            android:gravity="start|center_vertical"            android:hint="输入查询的关键字"            android:imeOptions="actionSearch"            android:singleLine="true"            android:textColor="@android:color/white"            android:textSize="16sp" />    </LinearLayout>    <ScrollView        android:layout_width="wrap_content"        android:layout_height="wrap_content">        <LinearLayout            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:orientation="vertical">            <LinearLayout                android:layout_width="match_parent"                android:layout_height="wrap_content"                android:orientation="vertical"                android:paddingLeft="20dp"                >                <TextView                    android:id="@+id/tv_tip"                    android:layout_width="match_parent"                    android:layout_height="50dp"                    android:gravity="left|center_vertical"                    android:text="搜索历史" />                <View                    android:layout_width="match_parent"                    android:layout_height="1dp"                    android:background="#EEEEEE"></View>                <com.cwvs.microlife.MyListView                    android:id="@+id/listView"                    android:layout_width="match_parent"                    android:layout_height="wrap_content"></com.cwvs.microlife.MyListView>            </LinearLayout>            <View                android:layout_width="match_parent"                android:layout_height="1dp"                android:background="#EEEEEE"></View>            <TextView                android:id="@+id/tv_clear"                android:layout_width="match_parent"                android:layout_height="40dp"                android:background="#F6F6F6"                android:gravity="center"                android:text="清除搜索历史" />            <View                android:layout_width="match_parent"                android:layout_height="1dp"                android:layout_marginBottom="20dp"                android:background="#EEEEEE"></View>        </LinearLayout>    </ScrollView></LinearLayout>

---

完整案例源代码