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Android实现搜索功能并本地保存搜索历史记录

2021-02-20 16:41 星期六 所属: 安卓教程 浏览:19

本实例完成起來非常简单,因此 能够立即用来置入新项目中应用,牵涉到的知识要点: 
– 数据库查询的增删实际操作 
– ListView和ScrollView的嵌入矛盾处理 
– 监视软键盘回车键按键设定为检索按键 
– 应用TextWatcher( )即时挑选 
– 已检索的关键词再度检索不反复加上到数据库查询 
– 刚进到页面布局软键盘不由于EditText而自弹出出

编码

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 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);
    // 复位控制
    initView();

    // 清除历史搜索
    tv_clear.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        deleteData();
        queryData("");
      }
    });

    // 输入框的电脑键盘检索键点一下回调函数
    et_search.setOnKeyListener(new View.OnKeyListener() {// 键入完后按键盘上的检索键

      public boolean onKey(View v, int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_ENTER && event.getAction() == KeyEvent.ACTION_DOWN) {// 改动回车作用
          // 先掩藏电脑键盘
          ((InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE)).hideSoftInputFromWindow(
              getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
          // 按完检索键后将当今查看的关键词保存,假如该关键词早已存有也不实行储存
          boolean hasData = hasData(et_search.getText().toString().trim());
          if (!hasData) {
            insertData(et_search.getText().toString().trim());
            queryData("");
          }
          // TODO 依据键入的內容模糊搜索产品,并自动跳转到另一个页面,由你自己去完成
          Toast.makeText(MainActivity.this, "clicked!", Toast.LENGTH_SHORT).show();

        }
        return false;
      }
    });

    // 输入框的文字转变 即时监视
    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("历史搜索");
        } else {
          tv_tip.setText("百度搜索");
        }
        String tempName = et_search.getText().toString();
        // 依据tempName去模糊数据库查询中是否有数据信息
        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 获得到item上边的文本,依据该关键词自动跳转到另一个网页页面查看,由你自己去完成
      }
    });

    // 插进数据信息,便于检测,不然第一次进入沒有数据信息怎么测试呀?
    Date date = new Date();
    long time = date.getTime();
    insertData("Leo"   time);

    // 第一次进入查看全部的历史数据
    queryData("");
  }

  /**
   * 插进数据信息
   */
  private void insertData(String tempName) {
    db = helper.getWritableDatabase();
    db.execSQL("insert into records(name) values('"   tempName   "')");
    db.close();
  }

  /**
   * 模糊搜索数据信息
   */
  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);
    // 建立adapter电源适配器目标
    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);
    // 设定电源适配器
    listView.setAdapter(adapter);
    adapter.notifyDataSetChanged();
  }
  /**
   * 查验数据库查询中是不是早已有此条纪录
   */
  private boolean hasData(String tempName) {
    Cursor cursor = helper.getReadableDatabase().rawQuery(
        "select id as _id,name from records where name =?", new String[]{tempName});
    //分辨是不是有下一个
    return cursor.moveToNext();
  }

  /**
   * 清除数据信息
   */
  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);

    // 调节EditText左侧的检索按键的尺寸
    Drawable drawable = getResources().getDrawable(R.drawable.search);
    drawable.setBounds(0, 0, 60, 60);// 第一0是距左侧间距,第二0是距上面间距,60分别是宽度
    et_search.setCompoundDrawables(drawable, null, null, null);// 只放左侧
  }
}



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

<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="键入查看的关键词"
      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="历史搜索" />

        <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="消除历史搜索" />

      <View
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:layout_marginBottom="20dp"
        android:background="#EEEEEE"></View>
    </LinearLayout>

  </ScrollView>
</LinearLayout>

之上便是文中的所有内容,期待对大伙儿的学习培训有一定的协助。

 

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