获取找不到符号:来自 ant 的方法 getSystemService

问题描述

我刚刚开始使用 android 并且 ant 给了我以下错误:

I am just starting out with android and ant is giving me the following error:

-compile: java:44: cannot find symbol
[javac] symbol  : method getSystemService(java.lang.String)
[javac] AudioManager am = (AudioManager)this.getSystemService(Context.AUDIO_SERVICE);
                                            ^

我不明白这个问题，因为我正在导入 android.media.AudioManager;

I don't understand the problem since I am importing android.media.AudioManager;

我的代码如下:

package com.example.findme;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.SmsMessage;
import android.widget.Toast;
import android.media.AudioManager;

public class SMSReceiver extends BroadcastReceiver
{
public final static String EXTRA_MESSAGE = "com.example.RemoVol.MESSAGE";
public final static String SILENT_MESSAGE = "Your phone has been silenced";
public final static String VOLUME_MESSAGE = "Your phone volume is normal";

@Override
public void onReceive(Context context, Intent intent)
{
//---get the SMS message passed in---
    Bundle bundle = intent.getExtras();
    SmsMessage msgs[] = null;
    String str ="";
    String testString="";
    if (bundle != null)
    {
        //---retrieve the SMS message received---
        Object pdus[]=(Object[]) bundle.get("pdus");
        msgs = new SmsMessage[pdus.length];
        for (int i=0; i<msgs.length; i++)
            {
                msgs[i] = SmsMessage.createFromPdu((byte[])pdus[i]);
                str += "SMS from" + msgs[i].getOriginatingAddress();
                str += " :";
                str +=msgs[i].getMessageBody().toString();
                testString=msgs[i].getMessageBody().toString();
                str += "\n";
            }
    //---display the new SMS message---
    Toast.makeText(context, str, Toast.LENGTH_SHORT).show();
        if(testString.equals("#silent"))
        {
            intent.putExtra(EXTRA_MESSAGE, SILENT_MESSAGE);
            AudioManager am = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
            am.setRingerMode(AudioManager.RINGER_MODE_SILENT);
        }
        else if(testString.equals("#volume"))
        {
        AudioManager am = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
        am.setRingerMode(AudioManager.RINGER_MODE_NORMAL);
        intent.putExtra(EXTRA_MESSAGE, VOLUME_MESSAGE);
        }
    }
}
}

我正在使用我的 android 项目根目录中的ant debug"命令进行编译.

I am compiling using the command "ant debug" in the root of my android project.

我希望这不是愚蠢和显而易见的事情.如果浪费了您的时间，请提前道歉.

I hope this isn't really something stupid and obvious. Apologies in advance if I have wasted your time.

感谢您对此进行审核.

推荐答案

您需要传入 BroadcastReciever 提供的上下文(您不能使用 this)

You need to pass in the context in which the BroadcastReciever is supplying (you can't use this)

//---display the new SMS message---
Toast.makeText(context, str, Toast.LENGTH_SHORT).show();
if(testString.equals("#silent"))
{
    intent.putExtra(EXTRA_MESSAGE, SILENT_MESSAGE);
    AudioManager am = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
    am.setRingerMode(AudioManager.RINGER_MODE_SILENT);
}
else if(testString.equals("#volume"))
{
    AudioManager am = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
    am.setRingerMode(AudioManager.RINGER_MODE_NORMAL);
    intent.putExtra(EXTRA_MESSAGE, VOLUME_MESSAGE);
}

这篇关于获取找不到符号:来自 ant 的方法 getSystemService的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！