我有一个简单的Activity来创建一个前台服务。我想将EditText中的值传递给Service，因为屏幕应该变暗。 MainActivity看起来像这样：
package com.mycompany.myapp;
import android.app.*;
import android.content.*;
import android.net.*;
import android.net.wifi.*;
import android.os.*;
import android.view.*;
import android.view.View.*;
import android.widget.*;
import android.provider.*;
import android.text.*;
public class MainActivity extends Activity
{
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final EditText edDim = (EditText) findViewById(R.id.DimVal);
edDim.setInputType(InputType.TYPE_CLASS_NUMBER);
Button btnStart =(Button) findViewById(R.id.button1);
btnStart.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
Intent intent = new Intent(getBaseContext(), MyService.class);
intent.putExtra("DimVal",edDim.getText());
startService(intent);
}
});
Button btnStop =(Button) findViewById(R.id.button2);
btnStop.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
stopService(new Intent(getBaseContext(), MyService.class));
}
});
}
}
这是服务：
package com.mycompany.myapp;
import android.app.*;
import android.content.*;
import android.net.*;
import android.os.*;
import android.provider.*;
import android.view.*;
import android.widget.*;
public class MyService extends Service
{
public int timeVal;
@Override
public IBinder onBind(Intent p1)
{
// TODO: Implement this method
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId)
{
// TODO: Implement this method
Toast.makeText(this,"Usługa uruchomiona",Toast.LENGTH_LONG).show();
timeVal = intent.getIntExtra("DimVal",100);
this.registerReceiver(this.mComnReceiver,
new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
Notification note = new Notification(0, null,
System.currentTimeMillis());note.flags = Notification.FLAG_NO_CLEAR;
this.startForeground(1,note);
return START_STICKY;
}
/*@Override
public void onDestroy()
{
// TODO: Implement this method
super.onDestroy();
Toast.makeText(this,"Usługa zatrzymana",Toast.LENGTH_LONG).show();
}*/
private BroadcastReceiver mComnReceiver = new BroadcastReceiver(){
@Override
public void onReceive(Context p1, Intent p2)
{
ConnectivityManager manager = (ConnectivityManager)
getSystemService(CONNECTIVITY_SERVICE);
boolean isWiFi = manager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isConnectedOrConnecting();
//NetworkInfo currentNetworkInfo = (NetworkInfo)
//p2.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);
if(isWiFi){
Settings.System.putInt(getContentResolver(), Settings.System.SCREEN_BRIGHTNESS, timeVal);
}else{
Settings.System.putInt(getContentResolver(), Settings.System.SCREEN_BRIGHTNESS, 300);
}
}
};
}
但上面的代码不起作用。如果WiFi每5分钟一次，我该如何检查服务？我意识到这个代码可能不是问题的最佳解决方案，但这是我编写的第一个Android程序（因此是注释代码）。 提前谢谢。
答案 0 :(得分：1)
public void timerForWifiCheck(long intervalVal, long countVal) {
new SCBP_TimerClass(intervalVal, countVal) {
@Override
public void onTick(long tickTime) {
//Wifi checking code write here
if(SCBP_NetworkUtil.checkInternetConnection(Context)){
//Do what you wnat e.g
finish()
}else{
//Return with some error code or msg
}
}
}
@Override
public void onFinish() {
//code when the timer finshes
}
}.start();
}
For this You need to add the below two classes:
public abstract class TimerClass {
/**
* Millis since epoch when alarm should stop.
*/
private final long mMillisInFuture;
/**
* The interval in millis that the user receives callbacks
*/
private final long mCountdownInterval;
private long mStopTimeInFuture;
private long mPauseTime;
private boolean mCancelled = false;
private boolean mPaused = false;
/**
* @param millisInFuture
* The number of millis in the future from the call to
* {@link #start()} until the countdown is done and
* {@link #onFinish()} is called.
* @param countDownInterval
* The interval along the way to receive {@link #onTick(long)}
* callbacks.
*/
public SCBP_TimerClass(long millisInFuture, long countDownInterval) {
mMillisInFuture = millisInFuture;
mCountdownInterval = countDownInterval;
}
/**
* Cancel the countdown.
*
* Do not call it from inside CountDownTimer threads
*/
public final void cancel() {
mHandler.removeMessages(MSG);
mCancelled = true;
}
/**
* Start the countdown.
*/
public synchronized final SCBP_TimerClass start() {
if (mMillisInFuture <= 0) {
onFinish();
return this;
}
mStopTimeInFuture = SystemClock.elapsedRealtime() + mMillisInFuture;
mHandler.sendMessage(mHandler.obtainMessage(MSG));
mCancelled = false;
mPaused = false;
return this;
}
/**
* Pause the countdown.
*/
public long pause() {
mPauseTime = mStopTimeInFuture - SystemClock.elapsedRealtime();
mPaused = true;
return mPauseTime;
}
/**
* Resume the countdown.
*/
public long resume() {
mStopTimeInFuture = mPauseTime + SystemClock.elapsedRealtime();
mPaused = false;
mHandler.sendMessage(mHandler.obtainMessage(MSG));
return mPauseTime;
}
/**
* Callback fired on regular interval.
*
* @param millisUntilFinished
* The amount of time until finished.
*/
public abstract void onTick(long millisUntilFinished);
/**
* Callback fired when the time is up.
*/
public abstract void onFinish();
private static final int MSG = 1;
// handles counting down
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
synchronized (SCBP_TimerClass.this) {
if (!mPaused) {
final long millisLeft = mStopTimeInFuture
- SystemClock.elapsedRealtime();
if (millisLeft <= 0) {
onFinish();
} else if (millisLeft < mCountdownInterval) {
// no tick, just delay until done
sendMessageDelayed(obtainMessage(MSG), millisLeft);
} else {
long lastTickStart = SystemClock.elapsedRealtime();
onTick(millisLeft);
// take into account user's onTick taking time to
// execute
long delay = lastTickStart + mCountdownInterval
- SystemClock.elapsedRealtime();
// special case: user's onTick took more than
// interval to
// complete, skip to next interval
while (delay < 0)
delay += mCountdownInterval;
if (!mCancelled) {
sendMessageDelayed(obtainMessage(MSG), delay);
}
}
}
}
}
};
}
public class NetworkUtil {
public static boolean checkInternetConnection(Context context) {
ConnectivityManager con_manager = (ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE);
if (con_manager.getActiveNetworkInfo() != null
&& con_manager.getActiveNetworkInfo().isAvailable()
&& con_manager.getActiveNetworkInfo().isConnected()) {
return true;
} else {
return false;
}
}
}
Hope this will help you to some extent.Cheers!
答案 1 :(得分：0)
我发现问题在于这行代码
intent.putExtra("DimVal",edDim.getText());
你应该这样做
intent.putExtra("DimVal",Integer.valueOf(edDim.getText().toString));
EditText getText，即edDim.getText()将为您提供可编辑而非内部值。另外，您将执行edDim.getText().toString将为您提供在传递之前更改为Integer所需的字符串值。
注意：在传递intent中的值之前，您需要为edDim设置null并检查验证;否则它可能会给你运行时错误。
关于WiFi的检查，最好创建一个接收连接检查更新的广播接收器，如果有连接，那么你可以检查它是Wifi还是移动数据，如果是移动数据则返回false。这样您就不需要每隔五分钟检查一次，这可能导致电池排水。
您可以查看Determining and Monitoring the Connectivity Status的此Android开发人员帖子。