我使用sqlite创建了一个Listview。 （在我的XML文件中，我有1个listview和1个edittext。如果我在edittext中部分键入名称，那么它应该检查sqllite数据库并带来数据。最初，Listbox只显示来自SQLITE数据库的一个条目。如果我输入了一些内容然后它应检查数据库并在Listview中显示该数据。
我的应用程序第一次显示一条记录，但是当我在文本框中输入字符时，我正在调用选择查询，但是它给出了以下错误：
03-05 23:19:12.926: E/Database(203): sqlite3_open_v2("/data/data/com.androidhive.androidlistviewwithsearch/databasessample", &handle, 1, NULL) failed
03-05 23:19:13.005: E/MainActivity(203): Could not create or Open the database
MainActivity.java
package com.androidhive.androidlistviewwithsearch;
import com.androidhive.androidlistviewwithsearch.DBHelper;
import java.util.ArrayList;
import java.util.HashMap;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
private ArrayList<String> results = new ArrayList<String>();
private String tableName = DBHelper.tableName;
private SQLiteDatabase newDB;
// List view
private ListView lv;
// Listview Adapter
ArrayAdapter<String> adapter;
// Search EditText
EditText inputSearch;
// ArrayList for Listview
ArrayList<HashMap<String, String>> productList;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Listview Data
String products[] = {"Dell Inspiron", "HTC One X", "HTC Wildfire S", "HTC Sense", "HTC Sensation XE",
"iPhone 4S", "Samsung Galaxy Note 800",
"Samsung Galaxy S3", "MacBook Air", "Mac Mini", "MacBook Pro"};
lv = (ListView) findViewById(R.id.list_view);
inputSearch = (EditText) findViewById(R.id.inputSearch);
openAndQueryDatabase();
// Adding items to listview
adapter = new ArrayAdapter<String>(this, R.layout.list_item, R.id.product_name, results);
lv.setAdapter(adapter);
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
int itemPosition = arg2;
// ListView Clicked item value
String itemValue = (String) lv.getItemAtPosition(arg2);
// Show Alert
Toast.makeText(getApplicationContext(),
"Position :"+itemPosition+" ListItem : " +itemValue , Toast.LENGTH_LONG)
.show();
}
});
/**
* Enabling Search Filter
* */
inputSearch.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
// When user changed the Text
Toast.makeText(getApplicationContext(),
"Position :"+ cs +" ListItem : " , Toast.LENGTH_LONG)
.show();
FetchQueryDatabase(cs);
//MainActivity.this.adapter.getFilter().filter(cs);
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
int arg3) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable arg0) {
// TODO Auto-generated method stub
}
});
}
private void openAndQueryDatabase() {
try {
DBHelper dbHelper = new DBHelper(this.getApplicationContext());
newDB = dbHelper.getWritableDatabase();
Cursor c = newDB.rawQuery("SELECT FirstName, Age FROM " +
tableName +
" LIMIT 1", null);
Log.d("ingu","vanthen1");
if (c != null ) {
if (c.moveToFirst()) {
do {
String firstName = c.getString(c.getColumnIndex("FirstName"));
int age = c.getInt(c.getColumnIndex("Age"));
results.add("Name: " + firstName + ",Age: " + age);
}while (c.moveToNext());
}
}
} catch (SQLiteException se ) {
Log.e(getClass().getSimpleName(), "Could not create or Open the database");
} finally {
if (newDB != null)
newDB.execSQL("DELETE FROM " + tableName);
newDB.close();
}
}
private void FetchQueryDatabase(CharSequence cs) {
try {
DBHelper dbHelper = new DBHelper(this.getApplicationContext());
newDB = dbHelper.getWritableDatabase();
String val=cs.toString();
Cursor c = newDB.rawQuery("SELECT FirstName, Age FROM " +
" where FirstName LIKE ? '%"+val+"%'", null);
if (c != null ) {
if (c.moveToFirst()) {
do {
String firstName = c.getString(c.getColumnIndex("FirstName"));
int age = c.getInt(c.getColumnIndex("Age"));
String age1 = age+"";
Log.d("age", age1);
results.add("Name: " + firstName + ",Age: " + age);
}while (c.moveToNext());
}
}
} catch (SQLiteException se ) {
Log.e(getClass().getSimpleName(), "Could not create or Open the database");
}
finally {
if (newDB != null)
newDB.execSQL("DELETE FROM " + tableName);
newDB.close();
}
}
}
DBHelper.Java
package com.androidhive.androidlistviewwithsearch;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
public class DBHelper extends SQLiteOpenHelper{
public SQLiteDatabase DB;
public String DBPath;
public static String DBName = "sample";
public static final int version = '1';
public static Context currentContext;
public static String tableName = "Resource";
public DBHelper(Context context) {
super(context, DBName, null, version);
currentContext = context;
DBPath = "/data/data/" + context.getPackageName() + "/databases";
createDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
private void createDatabase() {
boolean dbExists = checkDbExists();
if (dbExists) {
// do nothing
} else {
DB = currentContext.openOrCreateDatabase(DBName, 0, null);
DB.execSQL("CREATE TABLE IF NOT EXISTS " +
tableName +
" (LastName VARCHAR, FirstName VARCHAR," +
" Country VARCHAR, Age INT(3));");
DB.execSQL("INSERT INTO " +
tableName +
" Values ('M','shumi','India',25);");
DB.execSQL("INSERT INTO " +
tableName +
" Values ('C','sarah','India',25);");
DB.execSQL("INSERT INTO " +
tableName +
" Values ('D','Lavya','USA',20);");
DB.execSQL("INSERT INTO " +
tableName +
" Values ('V','Avi','EU',25);");
DB.execSQL("INSERT INTO " +
tableName +
" Values ('T','Shenoi','Bangla',25);");
DB.execSQL("INSERT INTO " +
tableName +
" Values ('L','Lamha','Australia',20);");
}
}
private boolean checkDbExists() {
SQLiteDatabase checkDB = null;
try {
String myPath = DBPath + DBName;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
} catch (SQLiteException e) {
// database does't exist yet.
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null ? true : false;
}
}