AutoCompleteTextView 与sqlite绑定实现记住用户输入的内容并自动提示

把用户输入的内容保存到数据库表中,然后用户输入时,进行模糊查询并把查询结果附到AutoCompleteTextView中。

1:activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" > <AutoCompleteTextView
android:id="@+id/actValue"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:completionThreshold="1"
android:singleLine="true"/> <Button
android:id="@+id/btnClick"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Click"/> </LinearLayout>

2:DbUtil.java

package com.example.autotest;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper; public class DbUtil extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 10; //当前数据库版本
private static final String DATABASE_NAME = "wzh.db"; private static final String TABLE_AUTO = "auto"; //国税邮件表 private static final String CREATE_TABLE_AUTO_SQL = "create table " +
TABLE_AUTO + "( _id integer primary key autoincrement, "+
" value varchar)"; public DbUtil(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
} /*
* 数据库第一次被创建时调用onCreate
*/
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(CREATE_TABLE_AUTO_SQL);
} /*
* 如果 DATABASE_VERSION 改变 系统会调用onUpgrade
*/
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("drop table if exists " + TABLE_AUTO); onCreate(db);
}
}

3:DBManager.java

package com.example.autotest;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase; public class DBManager {
private DbUtil dbUtil = null;
private SQLiteDatabase db = null; public DBManager(Context context){
dbUtil = new DbUtil(context);
db = dbUtil.getWritableDatabase();
} public boolean valueExist(String value){
int count = 0;
Cursor c = db.rawQuery("select _id from auto where value = ?",
new String[]{value});
if(c.moveToNext()){
count = c.getInt(c.getColumnIndex("_id"));
}
c.close();
return count>0?true:false;
} public void addAutoValue(String value){
if(value!=null && value.length()>0){
db.beginTransaction();
try{
String sql = "insert into auto(_id,value) values(null,?)";
db.execSQL(sql, new Object[]{value});
db.setTransactionSuccessful();
}finally{
db.endTransaction();
}
}
} public Cursor selectAutoValues(String value){
String sql = "select _id,value from auto where value like ? limit 10";
Cursor c = db.rawQuery(sql, new String[]{"%"+value+"%"});
return c;
} /**
* 关闭数据连接资源
*/
public void dbClose(){
if(null != db){
db.close();
}
}
}

4:AutoCompleteAdater.java

package com.example.autotest;

import android.content.Context;
import android.database.Cursor;
import android.widget.SimpleCursorAdapter; public class AutoCompleteAdater extends SimpleCursorAdapter{
private DBManager dbManager = null;
private Context context; // 查询字段
private String value; @SuppressWarnings("deprecation")
public AutoCompleteAdater(Context context, int layout, Cursor c,String from, int to) {
super(context, layout, c, new String[] { from },new int[] { to });
this.context = context;
this.value = from;
} /**
* 动态查询数据库
*/
@Override
public Cursor runQueryOnBackgroundThread(CharSequence constraint) {
if (constraint != null) {
return getDbManager().selectAutoValues((String) constraint);
} else {
return null;
}
} /**
* 这里设置在弹出的提示列表中点击某一项后的返回值,返回值将被显示在文本框中
*/
@Override
public CharSequence convertToString(Cursor cursor) {
return cursor.getString(cursor.getColumnIndex(value));
} public DBManager getDbManager(){
return dbManager==null?new DBManager(this.context):dbManager;
}
}

5:MainActivity.java

package com.example.autotest;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AutoCompleteTextView;
import android.widget.Button; public class MainActivity extends Activity {
private AutoCompleteTextView actValue = null;
private Button btnClick = null;
private DBManager dbManager = null; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main); actValue = (AutoCompleteTextView) findViewById(R.id.actValue);
btnClick = (Button)findViewById(R.id.btnClick); AutoCompleteAdater cursorAdapter = new AutoCompleteAdater(
this,
android.R.layout.simple_dropdown_item_1line,
null,
"value",
android.R.id.text1
);
actValue.setAdapter(cursorAdapter); dbManager = new DBManager(this); btnClick.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View arg0) {
String value = actValue.getText().toString();
dbManager.addAutoValue(value);
}
});
} @Override
protected void onDestroy() {
super.onDestroy();
if(dbManager!=null){
dbManager.dbClose();
}
}
}
java.lang.Object
   ↳ android.view.View
     ↳ android.widget.TextView
       ↳ android.widget.EditText
         ↳ android.widget.AutoCompleteTextView

  可以看出AutoCompleteTextView继承自EditText,所以它实际上也是一个文本编辑框,只是多了一个自动提示补全功能,EditText的所有功能AutoCompleteTextView都能实现,其对EditTextAPI进行了丰富。

上一篇:Java自学手记——集合


下一篇:Laravel PHP Web开发框架