嗨，我正在尝试制作一个 android 小部件。在这个小部件中，我试图通过调用 Web 服务并从中获取数据并在特定的关系间隔后将其显示在文本视图中来更新我的文本视图的值，但我遇到了异常。
Exception:java.lang.RuntimeException: Unable to start service com.example.newwidget.UpdateService@40ce9518withIntent{cmp=com.example.newwidget
/.UpdateService (has extras) }: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
这是我尝试过的代码，
小部件.java
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.widget.RemoteViews;
import android.widget.RemoteViews.RemoteView;
import android.widget.Toast;
public class Widget extends AppWidgetProvider {
@Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,
int[] appWidgetIds) {
Toast.makeText(context, "OnUpdate", Toast.LENGTH_LONG).show();
ComponentName thisWidget = new ComponentName(context,
Widget.class);
int[] allWidgetIds = appWidgetManager.getAppWidgetIds(thisWidget);
Toast.makeText(context, "allWidgetIds", Toast.LENGTH_LONG).show();
// Build the intent to call the service
Intent intent = new Intent(context.getApplicationContext(),
UpdateService.class);
Toast.makeText(context, "call UpdateService", Toast.LENGTH_LONG).show();
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, allWidgetIds);
Toast.makeText(context, "", Toast.LENGTH_LONG).show();
// Update the widgets via the service
context.startService(intent);
}
}
更新服务.java
import java.io.IOException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.ProgressDialog;
import android.app.Service;
import android.appwidget.AppWidgetManager;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;
import android.widget.RemoteViews;
import android.widget.Toast;
public class UpdateWidget extends Service {
private RemoteViews views;
private String url;
private String strAPIRender;
private final HttpClient Client = new DefaultHttpClient();
private String Content;
private String Error = null;
private ProgressDialog Dialog = new ProgressDialog(null);
private HttpResponse response;
private HttpEntity httpEntity;
@Override
public void onStart(Intent intent, int startId) {
Log.d("AppWidget.UpdateService", "onStart()");
Toast.makeText(UpdateWidget.this, "Onstart", Toast.LENGTH_LONG).show();
// Build the widget update for today
Toast.makeText(UpdateWidget.this, "Updateviews", Toast.LENGTH_LONG).show();
RemoteViews updateViews = buildUpdate(this);
Log.d("WordWidget.UpdateService", "update built");
Toast.makeText(UpdateWidget.this, "buildupdate finish", Toast.LENGTH_LONG).show();
// Push update for this widget to the home screen
ComponentName thisWidget = new ComponentName(this, WidgetAppActivity.class);
AppWidgetManager manager = AppWidgetManager.getInstance(this);
Toast.makeText(UpdateWidget.this, "final update", Toast.LENGTH_LONG).show();
manager.updateAppWidget(thisWidget, updateViews);
Log.d("WordWidget.UpdateService", "widget updated");
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
public RemoteViews buildUpdate(Context context) {
// Pick out month names from resources
Toast.makeText(UpdateWidget.this, "buildupdate", Toast.LENGTH_LONG).show();
url = "http://www.webservicex.net/currencyconvertor.asmx/ConversionRate?FromCurrency=USD&ToCurrency=INR";
grabURL(url);
Toast.makeText(UpdateWidget.this, "grabURL finish", Toast.LENGTH_LONG).show();
String result = strAPIRender;
views = new RemoteViews(context.getPackageName(), R.layout.activity_widget_app);
views.setTextViewText(R.id.update, result);
return views;
}
public void grabURL(String url) {
Toast.makeText(UpdateWidget.this, "in grabURL method", Toast.LENGTH_LONG).show();
Toast.makeText(null, "execute url", Toast.LENGTH_LONG).show();
try {
HttpGet httpget = new HttpGet(url);
ResponseHandler<String> responseHandler = new BasicResponseHandler();
Content = Client.execute(httpget, responseHandler);
} catch (ClientProtocolException e) {
Error = e.getMessage();
//cancel(true);
} catch (IOException e) {
Error = e.getMessage();
//cancel(true);
}
parseXml(Content);
}
public String parseXml(String content) {
try {
System.out.println(content);
try {
strAPIRender = XMLHandler.GetTagValue("double",content);
} catch (Exception e) {
System.out.println(" catch b");
}
} catch (Exception e) {
System.out.println(" exception in parseXML");
}
return strAPIRender;
}
}
清单文件
<uses-sdk android:minSdkVersion="8" />
<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" >
<receiver
android:name=".Widget"
android:icon="@drawable/ic_launcher"
android:label="A Widget" >
<intent-filter>
<action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
</intent-filter>
<meta-data
android:name="android.appwidget.provider"
android:resource="@xml/widget_info" />
</receiver>
<service android:name="com.example.newwidget.UpdateService"></service>
</application>