以下是我的代码。我在数据库中添加应用程序名称并在另一个屏幕上显示该应用程序，但问题是重复条目将显示Main类帮助我plz。如何从数据库中删除重复的条目。
public class SdcardAPkMgr extends ListActivity {
DatabaseHandler db;
public Drawable getAPKDrawable(String filePath) {
Drawable dr = null;
if (filePath != null) {
String PATH_PackageParser = "android.content.pm.PackageParser";
String PATH_AssetManager = "android.content.res.AssetManager";
try {
Class pkgParserCls = Class.forName(PATH_PackageParser);
Class[] typeArgs = new Class[1];
typeArgs[0] = String.class;
Constructor pkgParserCt =
pkgParserCls.getConstructor(typeArgs);
Object[] valueArgs = new Object[1];
valueArgs[0] = filePath;
Object pkgParser = pkgParserCt.newInstance(valueArgs);
DisplayMetrics metrics = new DisplayMetrics();
metrics.setToDefaults();
// PackageParser.Package mPkgInfo =
// packageParser.parsePackage(new
// File(apkPath), apkPath,
// metrics, 0);
typeArgs = new Class[4];
typeArgs[0] = File.class;
typeArgs[1] = String.class;
typeArgs[2] = DisplayMetrics.class;
typeArgs[3] = Integer.TYPE;
Method pkgParser_parsePackageMtd = pkgParserCls
.getDeclaredMethod("parsePackage",
typeArgs);
valueArgs = new Object[4];
valueArgs[0] = new File(filePath);
valueArgs[1] = filePath;
valueArgs[2] = metrics;
valueArgs[3] = 0;
Object pkgParserPkg = pkgParser_parsePackageMtd.invoke(
pkgParser, valueArgs);
Field appInfoFld =
pkgParserPkg.getClass().getDeclaredField(
"applicationInfo");
ApplicationInfo info = (ApplicationInfo) appInfoFld
.get(pkgParserPkg);
Class assetMagCls = Class.forName(PATH_AssetManager);
Constructor assetMagCt = assetMagCls
.getConstructor((Class[]) null);
Object assetMag = assetMagCt.newInstance((Object[]) null);
typeArgs = new Class[1];
typeArgs[0] = String.class;
Method assetMag_addAssetPathMtd = assetMagCls
.getDeclaredMethod("addAssetPath",
typeArgs);
valueArgs = new Object[1];
valueArgs[0] = filePath;
assetMag_addAssetPathMtd.invoke(assetMag, valueArgs);
Resources res = getResources();
typeArgs = new Class[3];
typeArgs[0] = assetMag.getClass();
typeArgs[1] = res.getDisplayMetrics().getClass();
typeArgs[2] = res.getConfiguration().getClass();
Constructor resCt =
Resources.class.getConstructor(typeArgs);
valueArgs = new Object[3];
valueArgs[0] = assetMag;
valueArgs[1] = res.getDisplayMetrics();
valueArgs[2] = res.getConfiguration();
res = (Resources) resCt.newInstance(valueArgs);
String label = null;
if (info.labelRes != 0) {
label = (String) res.getText(info.labelRes);
Log.d("Insert: ", "Inserting ..");
db.addContact(new Contact(label));
public class MainActivity extends Activity implements
OnItemClickListener {
/* whether or not to include system apps */
private static final boolean INCLUDE_SYSTEM_APPS = false;
DatabaseHandler db;
private List<App> loadInstalledApps(boolean includeSysApps) {
List<App> apps = new ArrayList<App>();
// the package manager contains the information about all installed
apps
PackageManager packageManager = getPackageManager();
List<PackageInfo> packs = packageManager.getInstalledPackages(0);
//PackageManager.GET_META_DATA
for(int i=0; i < packs.size(); i++) {
PackageInfo p = packs.get(i);
ApplicationInfo applicationInfo = p.applicationInfo;
String name =
packageManager.getApplicationLabel(applicationInfo).toString();
Log.d("Reading: ", "Reading all contacts..");
List<Contact> contacts = db.getAllContacts();
for (Contact cn : contacts) {
String log = "Id: "+cn.getID()+" ,Name: " +
cn.getName() ;
// String log = "Id: "+cn.getID()+" ,Name: " +
cn.getName() + " ,Phone: " + cn.getPhoneNumber();
// Writing Contacts to log
Log.d("Name: ", log);
//
if ( ((name).contains(cn.getName())))
{
App app = new App();
app.setTitle(p.applicationInfo.loadLabel(packageManager).toString());
app.setPackageName(p.packageName);
app.setVersionName(p.versionName);
app.setVersionCode(p.versionCode);
CharSequence description =
p.applicationInfo.loadDescription(packageManager);
app.setDescription(description != null ? description.toString() :
"");
apps.add(app);
}
}}
return apps;
}
package com.gfsmart.filemanager;
import android.database.sqlite.SQLiteOpenHelper;
public class DatabaseHandler extends SQLiteOpenHelper {
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "contactsManager";
// Contacts table name
private static final String TABLE_CONTACTS = "contacts";
// Contacts Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
//private static final String KEY_PH_NO = "phone_number";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
// String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"+ KEY_PH_NO + " TEXT" + ")";
String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT)";
db.execSQL(CREATE_CONTACTS_TABLE);
}
// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);
// Create tables again
onCreate(db);
}
/**
* All CRUD(Create, Read, Update, Delete) Operations
*/
// Adding new contact
void addContact(Contact contact) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, contact.getName()); // Contact Name
// values.put(KEY_PH_NO, contact.getPhoneNumber()); // Contact Phone
// Inserting Row
db.insert(TABLE_CONTACTS, null, values);
db.close(); // Closing database connection
}
// Getting single contact
Contact getContact(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_CONTACTS, new String[] { KEY_ID,
KEY_NAME }, KEY_ID + "=?",
new String[] { String.valueOf(id) }, null, null, null,
null);
if (cursor != null)
cursor.moveToFirst();
Contact contact = new Contact(Integer.parseInt(cursor.getString(0)),
cursor.getString(1));
// return contact
return contact;
}
// Getting All Contacts
public List<Contact> getAllContacts() {
List<Contact> contactList = new ArrayList<Contact>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_CONTACTS;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Contact contact = new Contact();
contact.setID(Integer.parseInt(cursor.getString(0)));
contact.setName(cursor.getString(1));
//contact.setPhoneNumber(cursor.getString(2));
// Adding contact to list
contactList.add(contact);
} while (cursor.moveToNext());
}
// return contact list
return contactList;
}
// Updating single contact
public int updateContact(Contact contact) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, contact.getName());
// values.put(KEY_PH_NO, contact.getPhoneNumber());
// updating row
return db.update(TABLE_CONTACTS, values, KEY_ID + " = ?",
new String[] { String.valueOf(contact.getID()) });
}
// Deleting single contact
public void deleteContact(Contact contact) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_CONTACTS, KEY_ID + " = ?",
new String[] { String.valueOf(contact.getID()) });
db.close();
}
// Getting contacts Count
public int getContactsCount() {
String countQuery = "SELECT * FROM " + TABLE_CONTACTS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
cursor.close();
// return count
return cursor.getCount();
}
}
public class Contact {
//private variables
int _id;
String _name;
// Empty constructor
public Contact(){
}
// constructor
public Contact(int id, String name){
this._id = id;
this._name = name;
}
// constructor
public Contact(String name){
this._name = name;
}
// getting ID
public int getID(){
return this._id;
}
// setting id
public void setID(int id){
this._id = id;
}
// getting name
public String getName(){
return this._name;
}
// setting name
public void setName(String name){
this._name = name;
}
答案 0 :(得分：0)
示例：
db.deleteContact();
db.addContact(new Contact(label));
将以下代码放在DatabaseHandler类中：
public int deleteContact() {
try {
SQLiteDatabase db = this.getWritableDatabase();
return db.delete(TABLE_CONTACTS, null, null);
} catch (Exception e) {
e.printStackTrace();
}
return 0;
}