The Android search function saves the search history locally.

The Android search function saves the search history locally.

The APP developed by my colleague has a search function and needs to display the search history. In my spare time, I helped her develop this function. Now I will extract this page into a demo and share it with you.

Effect:

This case is easy to implement, so it can be used directly in the project, involving knowledge points:
-Database addition, deletion, modification, and query operations
-Resolve nested conflicts between ListView and ScrollView
-Listen to the keyboard, press enter, and set it to search.
-Use TextWatcher () for Real-Time Filtering
-Search keywords again and add them to the database
-When you enter the page, the soft keyboard is automatically displayed instead of EditText.

Code

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) {    }}

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 lis TView; private TextView TV _clear; private response 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); // initialize the control initView (); // clear the search history TV _clear.setOnClic KListener (new View. onClickListener () {@ Override public void onClick (View v) {deleteData (); queryData ("");}}); // click the keyboard search key in the search box and call back et_search.setOnKeyListener (new View. onKeyListener () {// press the search key public boolean onKey (View v, int keyCode, KeyEvent event) {if (keyCode = KeyEvent. KEYCODE_ENTER & event. getAction () = KeyEvent. ACTION_DOWN) {// modify the Enter key function // hide the keyboard (InputMethodManager) getSystemServ Ice (Context. INPUT_METHOD_SERVICE )). hideSoftInputFromWindow (getCurrentFocus (). getWindowToken (), InputMethodManager. HIDE_NOT_ALWAYS); // press the search key to save the keyword of the current query. If the keyword already exists, the boolean hasData = hasData (et_search.getText () will not be saved (). toString (). trim (); if (! HasData) {insertData (et_search.getText (). toString (). trim (); queryData ("") ;}// TODO fuzzy queries the product based on the input content and jumps to another interface. You can implement Toast on your own. makeText (MainActivity. this, "clicked! ", Toast. LENGTH_SHORT ). show () ;}return false ;}}); // real-time listening for text changes in the search box 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 ("search history");} else {TV _tip.setText ("search result");} String tempName = et_search.getText (). toString (); // fuzzy query the database for queryData (tempName) based on 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 obtains the text above the item and jumps to another page for query based on this keyword. You can implement it yourself}); // inserts data for testing, otherwise, how can I test if no data is found for the first time? Date date = new Date (); long time = date. getTime (); insertData ("Leo" + time); // query all historical records for the first time ("");} /*** insert data */private void insertData (String tempName) {db = helper. getWritableDatabase (); db.exe cSQL ("insert into records (name) values ('" + tempName + "')"); db. close ();}/*** fuzzy query data */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 ); // create the adapter Object 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); // sets the adapter listView. setAdapter (adapter); adapter. notifyDataSetChanged ();}/*** check whether the database already has this Records */private boolean hasData (String tempName) {Cursor cursor = helper. getReadableDatabase (). rawQuery ("select id as _ id, name from records where name =? ", New String [] {tempName}); // determines whether a return cursor exists. moveToNext ();}/*** clear data */private void deleteData () {db = helper. getWritableDatabase (); db.exe cSQL ("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); // adjust the size of the Search button on the left of EditText. Drawable drawable = getResources (). getDrawable (R. drawable. search); drawable. setBounds (0, 0, 60, 60); // The first 0 is the left distance, the second 0 is the top distance, and the 60 is the long and wide et_search.setCompoundDrawables (drawable, null, null, null); // left only }}

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);    }}

Activity_main.xml

<Code class = "hljs 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 = "fill_parent" android: layout_weight = "264" android: background = "@ null" android: drawableleft = "@ drawable/search" android: drawablepadding = "8dp" android: gravity = "start | center_vertical" android: hint = "Enter the query keyword" android: imeoptions = "actionSearch" android: singleline = "true" android: textcolor = "@ android: color/white "android: textsize =" 16sp "> </edittext> </imageview> </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 = "search history"> <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> </textview> </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 = "Clear search history"> <view android: layout_width = "match_parent" android: layout_height = "1dp" android: layout_marginbottom = "20dp" android: background = "# EEEEEE"> </view> </textview> </linearlayout> </scrollview> </linearlayout> </code>