我正在尝试通过电容器自定义插件提供android服务。但是我出错了。
这是android / src / main / java中的自定义电容器插件:
可以从离子应用程序调用。我还将@PluginMethod返回类型设置为none。包io.ionic.starter;
import com.getcapacitor.JSObject;
import com.getcapacitor.NativePlugin;
import com.getcapacitor.Plugin;
import com.getcapacitor.PluginCall;
import com.getcapacitor.PluginMethod;
@NativePlugin()
public class CustomNativePlugin extends Plugin {
@PluginMethod(returnType=PluginMethod.RETURN_NONE)
public void customService() {
MainActivity mainActivity = new MainActivity();
mainActivity.startService();
call.resolve();
}
}
android服务:这是MyService
package io.ionic.starter;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.widget.Toast;
public class MyService extends Service {
public MyService() {
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// Let it continue running until it is stopped.
Toast.makeText(this, "Service Started", Toast.LENGTH_LONG).show();
return START_STICKY;
}
@Override
public void onDestroy() {
super.onDestroy();
Toast.makeText(this, "Service Destroyed", Toast.LENGTH_LONG).show();
}
}
并且从MainActivity我叫MyService,startService将触发,但之后出现错误。可能是因为有回叫功能。我不知道。
public void startService() {
startService(new Intent(getBaseContext(), MyService.class));
}
// Method to stop the service
public void stopService(View view) {
stopService(new Intent(getBaseContext(), MyService.class));
}
从离子应用程序的调用方法如下:
import { Plugins } from "@capacitor/core";
const { CustomNativePlugin } = Plugins;
runService(){
CustomNativePlugin.customService();
}
错误是:
2020-02-19 16:25:34.988 28206-28338/io.ionic.starter E/Capacitor: Unable to execute plugin method
com.getcapacitor.PluginInvocationException: Unable to invoke method customService on plugin io.ionic.starter.CustomNativePlugin
at com.getcapacitor.PluginHandle.invoke(PluginHandle.java:101)
at com.getcapacitor.Bridge$2.run(Bridge.java:537)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.os.HandlerThread.run(HandlerThread.java:65)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at com.getcapacitor.PluginHandle.invoke(PluginHandle.java:99)
at com.getcapacitor.Bridge$2.run(Bridge.java:537)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.os.HandlerThread.run(HandlerThread.java:65)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.content.ComponentName.<init>(ComponentName.java:130)
at android.content.Intent.<init>(Intent.java:5780)
at io.ionic.starter.MainActivity.startService(MainActivity.java:26)
at io.ionic.starter.CustomNativePlugin.customService(CustomNativePlugin.java:37)
at java.lang.reflect.Method.invoke(Native Method)
at com.getcapacitor.PluginHandle.invoke(PluginHandle.java:99)
at com.getcapacitor.Bridge$2.run(Bridge.java:537)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.os.HandlerThread.run(HandlerThread.java:65)
因为Android组件(服务,接收器,活动)可以通过startService(intent)方法触发服务的执行。我必须从上下文中调用它;
@PluginMethod(returnType = PluginMethod.RETURN_NONE)
public void customService(PluginCall call) {
call.resolve();
Intent service = new Intent(getContext(), MyIntentService.class);
getContext().startService(service);
}