Android 如何从服务类更新SimpleCursorAdapter列表视图?
我使用了Android 如何从服务类更新SimpleCursorAdapter列表视图?,android,sqlite,service,background,Android,Sqlite,Service,Background,我使用了SimpleCursorAdapter在我的活动类中将数据显示到列表中。我从Sqlite DB获取数据并应用到listview。我从服务类插入数据。在我的服务类中,我从WEB服务获取数据并将最新数据插入Sqlite移动数据库此服务类将每隔5秒运行一次,以检查最新的at Web服务,然后将其带到Sqlite db中插入。当新记录插入Sqlite db时,listview不会使用最新插入的记录进行更新。我已按如下方式实现了我的应用程序: MyActivity.java private MyS
SimpleCursorAdapter
在我的活动类中将数据显示到列表中。我从Sqlite DB获取数据并应用到listview
。我从服务类插入数据。在我的服务类中,我从WEB服务获取数据并将最新数据插入Sqlite移动数据库此服务类将每隔5秒运行一次,以检查最新的at Web服务,然后将其带到Sqlite db中插入。当新记录插入Sqlite db时,listview不会使用最新插入的记录进行更新。我已按如下方式实现了我的应用程序:
MyActivity.java
private MySqliteHelper msh;
ListView lst;
Cursor cursor;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
msh = new MySqliteHelper(MyActivity.this);
msh.openToWrite();
lst = ((ListView)findViewById(R.id.listView1));
cursor = msh.queueAll();
String getFromDB[] = new String[]{MySqliteHelper.KEY_CONTENT1,MySqliteHelper.KEY_CONTENT2};
int toView[] = new int[]{R.id.msgId,R.id.usrmsg};
lst.setAdapter(new SimpleCursorAdapter(this, R.layout.list, cursor, getFromDB, toView));
//calling service class
bindService(new Intent(ShoutGetMessagesActivity.this, ShoutRepeatService.class), mConnection, Context.BIND_AUTO_CREATE);
updateList();
}
private void updateList(){
cursor.requery();
}
RepeatService bg;
private ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className, IBinder binder) {
bg = ((RepeatService.MyBinder) binder).getService();
Toast.makeText(MyActivity.this, "Connected",
Toast.LENGTH_SHORT).show();
}
public void onServiceDisconnected(ComponentName className) {
bg = null;
}
};
}
ArrayList<NewMessages> result;
private MySqliteHelper msh;
private Timer timer = new Timer();
private static final long UPDATE_INTERVAL = 500;
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onCreate() {
msh = new MySqliteHelper(this);
msh.openToWrite();
pollForUpdates();
super.onCreate();
}
private void pollForUpdates() {
timer.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
Log.v("Last message ID", "====>"+MySqliteHelper.LastMsgID);
if(MySqliteHelper.LastMsgID==null){
MySqliteHelper.LastMsgID="0";
}
result = new ParseXml().convertUsersDetails(new Generic().getLatestFromWebService(MySqliteHelper.LastMsgID));
for(int i=0;i<result.size();i++){
String msgs =result.get(i).getMessages();
String msgID = result.get(i).getMsgId();
Log.v("messages", "------------>>>>"+msgs);
Log.v("messageIDs", "--------->>>>>>"+msgID);
msh.insert(msgID, msgs);
}
}
}, 0, UPDATE_INTERVAL);
Log.v(getClass().getSimpleName(), "Timer started.");
}
private void updateList(){
cursor.requery();
}
public class MyBinder extends Binder {
RepeatService getService()
{
return RepeatService.this;
}
}
}
RepeatService.java
private MySqliteHelper msh;
ListView lst;
Cursor cursor;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
msh = new MySqliteHelper(MyActivity.this);
msh.openToWrite();
lst = ((ListView)findViewById(R.id.listView1));
cursor = msh.queueAll();
String getFromDB[] = new String[]{MySqliteHelper.KEY_CONTENT1,MySqliteHelper.KEY_CONTENT2};
int toView[] = new int[]{R.id.msgId,R.id.usrmsg};
lst.setAdapter(new SimpleCursorAdapter(this, R.layout.list, cursor, getFromDB, toView));
//calling service class
bindService(new Intent(ShoutGetMessagesActivity.this, ShoutRepeatService.class), mConnection, Context.BIND_AUTO_CREATE);
updateList();
}
private void updateList(){
cursor.requery();
}
RepeatService bg;
private ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className, IBinder binder) {
bg = ((RepeatService.MyBinder) binder).getService();
Toast.makeText(MyActivity.this, "Connected",
Toast.LENGTH_SHORT).show();
}
public void onServiceDisconnected(ComponentName className) {
bg = null;
}
};
}
ArrayList<NewMessages> result;
private MySqliteHelper msh;
private Timer timer = new Timer();
private static final long UPDATE_INTERVAL = 500;
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onCreate() {
msh = new MySqliteHelper(this);
msh.openToWrite();
pollForUpdates();
super.onCreate();
}
private void pollForUpdates() {
timer.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
Log.v("Last message ID", "====>"+MySqliteHelper.LastMsgID);
if(MySqliteHelper.LastMsgID==null){
MySqliteHelper.LastMsgID="0";
}
result = new ParseXml().convertUsersDetails(new Generic().getLatestFromWebService(MySqliteHelper.LastMsgID));
for(int i=0;i<result.size();i++){
String msgs =result.get(i).getMessages();
String msgID = result.get(i).getMsgId();
Log.v("messages", "------------>>>>"+msgs);
Log.v("messageIDs", "--------->>>>>>"+msgID);
msh.insert(msgID, msgs);
}
}
}, 0, UPDATE_INTERVAL);
Log.v(getClass().getSimpleName(), "Timer started.");
}
private void updateList(){
cursor.requery();
}
public class MyBinder extends Binder {
RepeatService getService()
{
return RepeatService.this;
}
}
}
ArrayList结果;
私人MySqliteHelper msh;
专用计时器=新计时器();
私有静态最终长更新间隔=500;
@凌驾
公共IBinder onBind(意图arg0){
//TODO自动生成的方法存根
返回null;
}
@凌驾
public void onCreate(){
msh=新的MySqliteHelper(此);
msh.openToWrite();
pollForUpdates();
super.onCreate();
}
私有void pollForUpdates(){
timer.scheduleAtFixedRate(新TimerTask(){
@凌驾
公开募捐{
Log.v(“最后一个消息ID”,“=>”+MySqliteHelper.LastMsgID);
if(MySqliteHelper.LastMsgID==null){
MySqliteHelper.LastMsgID=“0”;
}
结果=new ParseXml().convertUsersDetails(new Generic().getLatestFromWebService(MySqliteHelper.LastMsgID));
对于(int i=0;i您可以在活动中使用广播接收器,并让服务在数据更新时发出广播。您必须定义自定义广播才能使其工作
首先。
像这样定义您的自定义操作
public static final String DATA_INSERTED = "WHATEVER_YOU_WANT"
当服务中的数据发生更改时,请执行此操作
Intent intent = new Intent (DATA_INSERTED);
sendBroadcast(intent)
初始化自定义广播接收器以侦听此特定的数据插入操作。重写onReceive方法。在onReceive方法中。您必须在适配器上调用notifydatasetchanged,这也意味着您需要对simplecursoradapter的引用。我将把广播接收器实现留给您来解决您可以在活动中使用广播接收器,并让服务在数据更新时发出广播。您必须定义自定义广播才能使其工作
首先。
像这样定义您的自定义操作
public static final String DATA_INSERTED = "WHATEVER_YOU_WANT"
当服务中的数据发生更改时,请执行此操作
Intent intent = new Intent (DATA_INSERTED);
sendBroadcast(intent)
初始化自定义广播接收器以侦听此特定的数据插入操作。重写onReceive方法。在onReceive方法中。您必须在适配器上调用notifydatasetchanged,这也意味着您需要对simplecursoradapter的引用。我将把广播接收器实现留给您来解决您可以使用intent创建广播,以便从服务的run()方法调用活动中的函数
private void pollForUpdates() {
timer.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
Log.v("Last message ID", "====>"+MySqliteHelper.LastMsgID);
if(MySqliteHelper.LastMsgID==null){
MySqliteHelper.LastMsgID="0";
}
result = new ParseXml().convertUsersDetails(new Generic().getLatestFromWebService(MySqliteHelper.LastMsgID));
for(int i=0;i<result.size();i++){
String msgs =result.get(i).getMessages();
String msgID = result.get(i).getMsgId();
Log.v("messages", "------------>>>>"+msgs);
Log.v("messageIDs", "--------->>>>>>"+msgID);
msh.insert(msgID, msgs);
}
}
*************************************
Intent intent = new Intent();
intent.setAction("com.example.updatelist");
sendBroadcast(intent); // finally broadcast
*************************************
}, 0, UPDATE_INTERVAL);
Log.v(getClass().getSimpleName(), "Timer started.");
}
您可以使用intent创建广播,以便从服务的run()方法调用活动中的函数
private void pollForUpdates() {
timer.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
Log.v("Last message ID", "====>"+MySqliteHelper.LastMsgID);
if(MySqliteHelper.LastMsgID==null){
MySqliteHelper.LastMsgID="0";
}
result = new ParseXml().convertUsersDetails(new Generic().getLatestFromWebService(MySqliteHelper.LastMsgID));
for(int i=0;i<result.size();i++){
String msgs =result.get(i).getMessages();
String msgID = result.get(i).getMsgId();
Log.v("messages", "------------>>>>"+msgs);
Log.v("messageIDs", "--------->>>>>>"+msgID);
msh.insert(msgID, msgs);
}
}
*************************************
Intent intent = new Intent();
intent.setAction("com.example.updatelist");
sendBroadcast(intent); // finally broadcast
*************************************
}, 0, UPDATE_INTERVAL);
Log.v(getClass().getSimpleName(), "Timer started.");
}
谢谢你的回答,但迟到记录在最后一个位置添加。有没有机会在第一个位置添加迟到记录?谢谢你的回答,但迟到记录在最后一个位置添加。有没有机会在第一个位置添加迟到记录?