Android 在listview中格式化文本(从数据库填充)
我想格式化db中的文本,将其填充到listview中。 在日志中,文本具有正确的格式,但在设备上,文本类似于Android 在listview中格式化文本(从数据库填充),android,database,sqlite,listview,Android,Database,Sqlite,Listview,我想格式化db中的文本,将其填充到listview中。 在日志中,文本具有正确的格式,但在设备上,文本类似于 packagename.class@52aad49c 日志文本: 05-09 16:06:02.146: D/Name:(1750): Id: 1 ,Name: Ravi ,Phone: 9100000000 05-09 16:06:02.146: D/Name:(1750): Id: 2 ,Name: Srinivas ,Phone: 9199999999 05-09 16:06:
packagename.class@52aad49c
日志文本:
05-09 16:06:02.146: D/Name:(1750): Id: 1 ,Name: Ravi ,Phone: 9100000000
05-09 16:06:02.146: D/Name:(1750): Id: 2 ,Name: Srinivas ,Phone: 9199999999
05-09 16:06:02.146: D/Name:(1750): Id: 3 ,Name: Tommy ,Phone: 9522222222
05-09 16:06:02.146: D/Name:(1750): Id: 4 ,Name: Karthik ,Phone: 9533333333
05-09 16:06:02.146: D/Name:(1750): Id: 5 ,Name: Ravi ,Phone: 9100000000
这是写入DB并填充listview的代码:
//DB
DatabaseHandler db = new DatabaseHandler(this);
/**
* CRUD Operations
* */
// Inserting Contacts
Log.d("Insert: ", "Inserting ..");
db.addContact(new Contact("Ravi", "9100000000"));
db.addContact(new Contact("Srinivas", "9199999999"));
db.addContact(new Contact("Tommy", "9522222222"));
db.addContact(new Contact("Karthik", "9533333333"));
// Reading all contacts
Log.d("Reading: ", "Reading all contacts..");
List<Contact> contacts = db.getAllContacts();
for (Contact cn : contacts) {
String log = "Id: "+cn.getID()+" ,Name: " + cn.getName() + " ,Phone: " + cn.getPhoneNumber();
// Writing Contacts to log
Log.d("Name: ", log);
//fill listview
ArrayAdapter<Contact> adapterVerlauf = new ArrayAdapter<Contact>(Ende.this, android.R.layout.simple_list_item_1, contacts);
ListView Verlauf = (ListView) findViewById(R.id.listview);
Verlauf.setAdapter(adapterVerlauf);
//DB
DatabaseHandler db=新的DatabaseHandler(此);
/**
*积垢作业
* */
//插入联系人
日志d(“插入:”,“插入..”);
db.addContact(新联系人(“Ravi”,“9100000000”));
db.addContact(新联系人(“Srinivas”、“919999999”);
db.addContact(新联系人(“Tommy”,“952222”));
db.addContact(新联系人(“Karthik”、“9533333”);
//读取所有联系人
日志d(“读取:”,“读取所有联系人…”);
List contacts=db.getAllContacts();
用于(联系人cn:联系人){
字符串log=“Id:”+cn.getID()+”,名称:“+cn.getName()+”,电话:“+cn.getPhoneNumber()”;
//将联系人写入日志
Log.d(“名称:”,Log);
//填充列表视图
ArrayAdapter AdapterLauf=新的ArrayAdapter(Ende.this,android.R.layout.simple\u list\u item\u 1,contacts);
ListView Verlauf=(ListView)findViewById(R.id.ListView);
设置适配器(AdapterLauf);
我的数据库处理程序:
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" + ")";
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_PH_NO }, 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), cursor.getString(2));
// 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();
}
}
公共类DatabaseHandler扩展了SQLiteOpenHelper{
//所有静态变量
//数据库版本
私有静态最终int数据库_VERSION=1;
//数据库名称
私有静态最终字符串数据库\u NAME=“contactsManager”;
//联系人表名称
专用静态最终字符串表\u CONTACTS=“CONTACTS”;
//联系人表列名称
私有静态最终字符串密钥\u ID=“ID”;
私有静态最终字符串键\u NAME=“NAME”;
专用静态最终字符串密钥\u PH\u NO=“电话号码”;
公共数据库处理程序(上下文){
super(上下文、数据库名称、null、数据库版本);
}
//创建表
@凌驾
public void onCreate(SQLiteDatabase db){
字符串CREATE_CONTACTS_TABLE=“CREATE TABLE”+TABLE_CONTACTS+”(“
+键ID+“整数主键”+“键名称+”文本
+键号+“文本”+”;
execSQL(创建联系人表);
}
//升级数据库
@凌驾
public void onUpgrade(SQLiteDatabase db,int-oldVersion,int-newVersion){
//删除旧表(如果存在)
db.execSQL(“如果存在删除表”+表_联系人);
//再次创建表
onCreate(db);
}
/**
*所有CRUD(创建、读取、更新、删除)操作
*/
//添加新联系人
无效添加联系人(联系人联系人){
SQLiteDatabase db=this.getWritableDatabase();
ContentValues=新的ContentValues();
value.put(KEY_NAME,contact.getName());//contact NAME
value.put(键号,contact.getPhoneNumber());//联系电话
//插入行
db.插入(表_触点,空,值);
db.close();//关闭数据库连接
}
//获得单一联系
联系人getContact(int-id){
SQLiteDatabase db=this.getReadableDatabase();
Cursor Cursor=db.query(TABLE_CONTACTS,新字符串[]{KEY_ID,
密钥名称,密钥号,密钥ID+“=?”,
新字符串[]{String.valueOf(id)},null,null,null,null);
如果(光标!=null)
cursor.moveToFirst();
Contact Contact=新联系人(Integer.parseInt(cursor.getString(0)),
cursor.getString(1),cursor.getString(2));
//回接
回接;
}
//获取所有联系人
公共列表getAllContacts(){
List contactList=new ArrayList();
//选择所有查询
String selectQuery=“SELECT*FROM”+表格\联系人;
SQLiteDatabase db=this.getWritableDatabase();
Cursor Cursor=db.rawQuery(selectQuery,null);
//循环遍历所有行并添加到列表
if(cursor.moveToFirst()){
做{
触点=新触点();
setID(Integer.parseInt(cursor.getString(0));
contact.setName(cursor.getString(1));
contact.setPhoneNumber(cursor.getString(2));
//将联系人添加到列表中
联系人列表。添加(联系人);
}while(cursor.moveToNext());
}
//返回联系人列表
返回联系人列表;
}
//更新单个联系人
public int updateContact(联系人){
SQLiteDatabase db=this.getWritableDatabase();
ContentValues=新的ContentValues();
value.put(KEY_NAME,contact.getName());
value.put(键号,contact.getPhoneNumber());
//更新行
返回db.update(表联系人、值、键ID+“=?”,
新字符串[]{String.valueOf(contact.getID())};
}
//删除单个联系人
公共联系人(联系人){
SQLiteDatabase db=this.getWritableDatabase();
db.delete(表触点,键ID+“=?”,
新字符串[]{String.valueOf(contact.getID())};
db.close();
}
//获取联系人计数
public int getcontactscont(){
String countQuery=“SELECT*FROM”+表\u联系人;
SQLiteDatabase db=this.getReadableDatabase();
Cursor Cursor=db.rawQuery(countQuery,null);
cursor.close();
//返回计数
返回cursor.getCount();
}
}
您可以覆盖Contact类的toString方法:
@Override
public String toString() {
return "Id: " + getID() + " ,Name: " + getName() + " ,Phone: " + getPhoneNumber();
}
您的代码中缺少的是从
联系人
对象到列表视图
中视图的映射。我现在能想到的最基本的解决方案看起来很简单
Override the toString() method of your objects to determine what text will be displayed for the item in the list.
public class ContactAdapter extends BaseAdapter {
private final List<Contact> contactList;
private final LayoutInflater layoutInflater;
public ContactAdapter(Context context, List<Contact> contactList) {
this.layoutInflater = LayoutInflater.from(context);
this.contactList = contactList;
}
@Override
public int getCount() {
return this.contactList.size();
}
@Override
public Contact getItem(int position) {
return this.contactList.get(position);
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// You get the Contact object for the current position
Contact contact = getItem(position);
// If the convertView is null we need to create a new one.
if(convertView == null) {
convertView = this.layoutInflater.inflate(R.layout.list_item, parent, false);
// We pass the view to our ViewHolder and set the ViewHolder as tag to the View
ContactViewHolder holder = new ContactViewHolder(convertView);
convertView.setTag(holder);
}
// We get the ViewHolder from the tag and bind the Contact object to it.
ContactViewHolder holder = (ContactViewHolder) convertView.getTag();
holder.bind(contact);
return convertView;
}
private class ContactViewHolder {
private final TextView tvName;
private final TextView tvTelephone;
public ContactViewHolder(View convertView) {
// We get the TextViews from the convertView
this.tvName = (TextView) convertView.findViewById(R.id.tvName);
this.tvTelephone = (TextView) convertView.findViewById(R.id.tvTelephone);
}
public void bind(Contact contact) {
// We set the values of our TextViews according to the Contact object.
this.tvName.setText(contact.getName());
this.tvTelephone.setText(contact.getTelephoneNumber());
}
}
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/tvName"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/tvTelephone"
android:layout_below="@id/tvName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</RelativeLayout>