Question

我正在尝试显示以下状态：

电池电量（t / f） USB收费（t / f）电池交流电（t / f）电池电量（百分比）

在扩展控件中更改充电器连接后。

在onResume（）中，广播接收器状态

无法解析方法 'registerReceiver（android.content.BroadcastReceiver）

它在onPause（）中注册没有问题。感谢您的帮助，这似乎是一个很难解决的问题。

MainActivity：

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.BatteryManager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    BroadcastReceiver broadcastReceiver;
    StringBuilder stringBuilder;
    public MyReciever myReciever= new MyReciever();
    Intent intent;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        broadcastReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                myReciever.onReceive(MainActivity.this, intent);
                StringBuilder stringBuilder = new StringBuilder();

                IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
                intent = registerReceiver(null, ifilter);
                int status = intent.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
                boolean isCharging = status == BatteryManager.BATTERY_STATUS_CHARGING ||status == BatteryManager.BATTERY_STATUS_FULL;
                int chargePlug = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
                boolean usbCharge = chargePlug == BatteryManager.BATTERY_PLUGGED_USB;
                boolean acCharge = chargePlug == BatteryManager.BATTERY_PLUGGED_AC;
                int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
                int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
                float batteryPct = level / (float)scale;

                stringBuilder.append(String.valueOf(isCharging));
                stringBuilder.append(String.valueOf(usbCharge));
                stringBuilder.append(String.valueOf(acCharge));
                stringBuilder.append(String.valueOf(batteryPct));

                String str = stringBuilder.toString();
                TextView display = (TextView)findViewById(R.id.results);
                display.setText(str);

            }
        };
    }
///Not Registering here
    @Override
    protected void onResume() {
        super.onResume();
        registerReceiver(broadcastReceiver);
    }

    @Override
   protected void onPause() {
        super.onPause();
        unregisterReceiver(broadcastReceiver);
    }
}

MyReceiver：

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class MyReciever extends BroadcastReceiver {
    @Override

            public void onReceive(Context context, Intent intent) {

                Intent newintent = new Intent(context.getApplicationContext(), MainActivity.class);
                newintent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
                context.startActivity(newintent);



            }
        }

activity_main.XML：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:id="@+id/results"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

Answer 1

您的问题是方法registerReciever接受2个参数，而不是1。

这些参数是

要注册的广播接收器
意图过滤器

由于您仅提供第一个参数，因此找不到该方法，并且因为没有版本的方法（重载方法）仅采用一个参数。

因此，要解决此问题，您必须调用如下方法：

protected void onResume() {
    registerReceiver(broadcastReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
    super.onResume();
}

此处https://developer.android.com/reference/android/content/IntentFilter.html

提供了创建IntentFilter的文档。

Answer 2

尝试

@Override
protected void onResume() {
    registerReceiver(broadcastReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
    super.onResume();
}

有关更多信息，请参阅https://developer.android.com/training/monitoring-device-state/battery-monitoring.html

广播接收器未在onPause（）进行时向onResume（）注册

2 个答案: