我相信这是确定Wifi是否已连接或断开的正确方法。
在BroadcastReceiver中的onReceive()方法：只需放置一个简单的检查(这是由SharedPreferences实现的逻辑)：
package com.example.broadcasttest;
import java.util.List;
import java.util.Random;
import android.app.Activity;
import android.app.ActivityManager;
import android.app.ActivityManager.RunningTaskInfo;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.util.Log;
import android.widget.Toast;
public class CustomReceiver extends BroadcastReceiver {
boolean isInternetPresent = false;
@Override
public void onReceive(Context context, Intent intent) {
ActivityManager am = (ActivityManager) context
.getSystemService(Activity.ACTIVITY_SERVICE);
String packageName = am.getRunningTasks(1).get(0).topActivity
.getPackageName();
@SuppressWarnings("deprecation")
List<RunningTaskInfo> taskInfo = am.getRunningTasks(1);
ComponentName componentInfo = taskInfo.get(0).topActivity;
if(packageName.equals("com.example.broadcasttest") && taskInfo.get(0).topActivity.getClassName().toString().equals("com.example.broadcasttest.MainActivity"))
{
ConnectionDetector cd = new ConnectionDetector(context);
isInternetPresent = cd.isConnectingToInternet();
if (isInternetPresent) {
SharedPreferences sharedPreferences=context.getSharedPreferences("FLAG", Context.MODE_PRIVATE);
String check=sharedPreferences.getString("check","");
if(check.equals("chkd1")){
Log.d("activity name", "CURRENT Activity ::" + taskInfo.get(0).topActivity.getClassName()+" Package Name : "+componentInfo.getPackageName());
String abc = context.getClass().toString();
Toast.makeText(context, "hiiii "+abc, Toast.LENGTH_SHORT).show();
Log.e("ghorar kochu", "checking:");
MainActivity m = new MainActivity();
m.abc(context);
}
else if(check.equals("chkd"))
{
Log.e("Thanks For the checking", "checking:"+check);
}
}
else if (!isInternetPresent) {
SharedPreferences sharedPreferences1=context.getSharedPreferences("FLAG", Context.MODE_PRIVATE);
SharedPreferences.Editor editor1=sharedPreferences1.edit();
editor1.putString("check","chkd1");
editor1.commit();
}
}
}
}
这是实际的接收器类。现在进入主活动。
package com.example.broadcasttest;
import java.net.URLEncoder;
import java.util.ArrayList;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
public class MainActivity extends Activity {
Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SharedPreferences sharedPreferences1=getSharedPreferences("FLAG", Context.MODE_PRIVATE);
SharedPreferences.Editor editor1=sharedPreferences1.edit();
editor1.putString("check","chkd1");
editor1.commit();
btn = (Button)findViewById(R.id.btn);
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent in =new Intent(MainActivity.this,Second.class);
startActivity(in);
}
});
}
public void abc(Context context){
try{
SharedPreferences sharedPreferences1=context.getSharedPreferences("FLAG", Context.MODE_PRIVATE);
SharedPreferences.Editor editor1=sharedPreferences1.edit();
editor1.putString("check","chkd");
editor1.commit();
}
catch(NullPointerException e)
{
e.printStackTrace();
}
new JsonForTimeLineList().execute();
}
class JsonForTimeLineList extends AsyncTask<Void, Void, Void> {
private String msg = null;
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected Void doInBackground(Void... params) {
return null;
}
@Override
protected void onPostExecute(Void resultaaa) {
Log.e("hi", "helo");
}
}
}
这段代码仅在您的应用程序处于“onresume”状态并且在MainActivity中时才能正常工作。
以下是我的ConnectionDetector类。通过它，我检查wifi连接。
package com.example.broadcasttest;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
public class ConnectionDetector {
private Context _context;
public ConnectionDetector(Context context){
this._context = context;
}
public boolean isConnectingToInternet(){
ConnectivityManager connectivity = (ConnectivityManager) _context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivity != null)
{
NetworkInfo[] info = connectivity.getAllNetworkInfo();
if (info != null)
for (int i = 0; i < info.length; i++)
if (info[i].getState() == NetworkInfo.State.CONNECTED)
{
return true;
}
}
return false;
}
}
这是我的Manifest.xml文件
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.broadcasttest"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".Second"
android:label="@string/app_name" >
</activity>
<receiver android:name="com.example.broadcasttest.CustomReceiver">
<intent-filter >
<action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
</intent-filter>
</receiver>
</application>
</manifest>
当我启用WiFi时，以下是我的日志记录。
11-19 20:13:11.474: D/activity name(25417): CURRENT Activity ::com.example.broadcasttest.MainActivity Package Name : com.example.broadcasttest
11-19 20:13:11.481: E/ghorar kochu(25417): checking:
11-19 20:13:11.542: E/hi(25417): helo
11-19 20:13:11.573: V/RenderScript(25417): Application requested CPU execution
11-19 20:13:11.580: V/RenderScript(25417): 0xb90a7850 Launching thread(s), CPUs 4
11-19 20:13:17.158: E/Thanks For the checking(25417): checking:chkd
如果您有任何疑问，请告诉我。
