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 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); // 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 } } 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="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>
