android实现搜索功能并将搜索结果保存到SQLite中(实例代码)

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时间:2020-10-14
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android实现搜索功能并将搜索结果保存到SQLite中(实例代码)android实现搜索功能并将搜索结果保存到SQLite中(实例代码)
android实现搜索功能并将搜索结果保存到SQLite中(实例代码)

涉及要点:

ListView+EditText+ScrollView实现搜索效果显示 监听软键盘回车执行搜索 使用TextWatcher( )实时筛选 将搜索内容存储到SQLite中(可清空历史记录) 监听EditText的焦点,获得焦点弹出软键盘同时显示搜索历史,失去焦点隐藏软件盘和ListView。

实现过程比较简单,都是常用的,这里就不讲解了。代码可直接复制使用。

实现过程:

MainActivity.java

public class MainActivity extends Activity {

 private EditText et_search;
 private TextView tv_tip;
 private MyListView listView;
 private TextView tv_clear;
 ScrollView scrollView;
 private RecordSQLiteOpenHelper helper = new RecordSQLiteOpenHelper(this);
 private SQLiteDatabase db;
 private BaseAdapter adapter;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main); 
 initView(); // 初始化控件
 // 清空搜索历史
 tv_clear.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View v) {
  deleteData();
  queryData("");
  }
 });
 
 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
   // 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("");
   }
   Toast.makeText(MainActivity.this, "点击软键盘搜索!", Toast.LENGTH_SHORT).show();
  }
  return false;
  }
 });

 et_search.setOnFocusChangeListener(new View.OnFocusChangeListener() {
  @Override
  public void onFocusChange(View view, boolean b) {
  if (b) { //获得
   scrollView.setVisibility(View.VISIBLE);
  } else {//市区焦点
   scrollView.setVisibility(View.GONE);
  }
  }
 });

 // 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();
  ((InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE)).hideSoftInputFromWindow(
   getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS); //隐藏软键盘
  et_search.clearFocus();
  et_search.setText("");
  }
 });

 // 插入测试数据
 Date date = new Date();
 long time = date.getTime();
 insertData("LY" + time);
 queryData(""); // 第一次进入查询所有的历史记录
 }

 /**
 * 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);
 scrollView = findViewById(R.id.showSearch);
 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
 }
}

RecordSQLiteOpenHelper.java

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) {

 }
}

MyListView.java

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:focusable="true"
 android:focusableInTouchMode="true"
 android:orientation="vertical"
 tools:context=".MainActivity">

 <LinearLayout
 android:layout_width="fill_parent"
 android:layout_height="50dp"
 android:background="#be9999"
 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="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:id="@+id/showSearch"
 android:layout_width="wrap_content"
 android:layout_height="300dp"
 android:visibility="gone">

 <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" />

  <liyue.edu.cn.ncst.app.MyListView
   android:id="@+id/listView"
   android:layout_width="match_parent"
   android:layout_height="wrap_content" />
  </LinearLayout>

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

  <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" />
 </LinearLayout>

 </ScrollView>

</LinearLayout>

完整代码下载 demo

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