如何从扩展的BroadcastReceiver类调用MainActivity函数

Question

I can not find answer for this problem. I am building some Android application based on sms services and I found callback very difficult. I want/need to call my primary application class MainActivity from inside function onReceive (class SMSReceiver ). Toast works perfectly but any attempt to call public void OnSmsReceived() (class MainActivity ) is unsuccessful.

// Main class
public class MainActivity extends Activity {
  public void OnSmsReceived() {
    System.out.println(TAG + ": OnSmsReceived " + "OK ");
  }
  /* more not important at this moment code bellow */
}


// Brodcast class
public class SMSReceiver extends BroadcastReceiver {
  private static final String TAG = "SMSReceiver";
  @Override
  public void onReceive(Context context, Intent intent) {
    Toast.makeText(context, "SMS received.", Toast.LENGTH_LONG).show();
    System.out.println(TAG + ": " + "onReceive");

    //How to call MainActivity form here?

  }
}

Answer 1

This is really working code
Thank you for intent ...

//Android Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="sms.pack.sms201"
    android:versionCode="1"
    android:versionName="1.0" >
    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="8" />
    <uses-permission android:name="android.permission.BROADCAST_SMS"/>
    <uses-permission android:name="android.permission.READ_SMS" />
    <uses-permission android:name="android.permission.SEND_SMS" />
    <uses-permission android:name="android.permission.RECEIVE_SMS" />
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="sms.pack.sms201.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>        
        <receiver 
            android:name="sms.pack.sms201.SMSReceiver" 
            android:enabled="true" 
            android:exported="true" 
            android:permission="android.permission.BROADCAST_SMS"> 
            <intent-filter android:priority="1000"> 
                <action android:name="android.provider.Telephony.SMS_RECEIVED"/> 
            </intent-filter> 
        </receiver>        
    </application>
</manifest>

//SMSReceiver class
public class SMSReceiver extends BroadcastReceiver {
  private static final String TAG = "SMSReceiver";
  public static String Test = "empty";
  @Override
  public void onReceive(Context context, Intent intent) {
    Log.v(TAG, "onReceive");
    Toast.makeText(context, "SMS received.", Toast.LENGTH_LONG).show();
    Bundle bundle = intent.getExtras();
    if( bundle != null) {
      Log.v(TAG, "onReceive.bundle != null");
      Test = String.valueOf(bundle.size());
    }    
    Intent callingIntent = new Intent(context, MainActivity.class);
    callingIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    callingIntent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
    String value = "Extra val=" + Test;
    callingIntent.putExtra("SMSR", value);
    context.startActivity(callingIntent);    
  }
}

//MainActivity class
public class MainActivity extends Activity {
  private static final String TAG = "MainActivity";
  TextView tvGenLog;    
    protected void appendGenLog(String txt) {
      txt = tvGenLog.getText() + txt + "\r\n";
        tvGenLog.setText(txt);
    }
    private String memberFieldString;
    @Override
  protected void onNewIntent(Intent intent) {
    appendGenLog(TAG + ".onNewIntent");
    memberFieldString = intent.getStringExtra("SMSR");
    appendGenLog("memberFieldString=" + memberFieldString);    
    appendGenLog("Take data from SMSReceiver,");    
    appendGenLog("SMSR=" + SMSReceiver.Test);    
    super.onNewIntent(intent);
    } // End of onNewIntent(Intent intent)
  @Override
  protected void onResume() { 
    super.onResume();   
    //appendGenLog(TAG + ".onResume");   
    if (getIntent()!=null && getIntent().getExtras()!=null) {
      appendGenLog(TAG + ".onResume" + ":" + getIntent().getExtras().getString("SMSR"));  
    }
      else {
      appendGenLog(TAG + ".onResume" + ": null");  
    }
  }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);     
        Log.v(TAG, ".onCreate");        
        tvGenLog = (TextView) findViewById(R.id.tvGenLog);        
        appendGenLog(TAG + " Created");
    }   
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
  }    
}

Answer 2

在onReceive方法中使用上下文并调用context.startActivity（context，yourActivity.class）;

Answer 3

you can't use context.startActivity(context , MainActivity.class);

but you can choose below method to resolve this issue:

intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent);
context.startActivity(intent, bundle)

Answer 4

I experimented lots of approaches.

I did not say but it is for targetSdkVersion="8"
and some of those functions you gave me did not work on this old system
I could not find working way with use of context and intent. This always caused crash.

I found way with static fields and function in MainActivity,
even that works and print something, it crushed after that....

After all this works for me very well.
Of course it is draft but this allow to work with main class.

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="sms.pack.sms0"
        android:versionCode="1"
        android:versionName="1.0" >
    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="8" /> 
    <uses-permission android:name="android.permission.BROADCAST_SMS"/>
    <uses-permission android:name="android.permission.RECEIVE_SMS" />
    <uses-permission android:name="android.permission.READ_SMS" />
    <uses-permission android:name="android.permission.SEND_SMS" />
    <uses-permission android:name="android.permission.CALL_PHONE" />
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="sms.pack.sms0.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>         
    </application>
</manifest>

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">sms0</string>
    <string name="action_settings">Settings</string>
    <string name="sGenInfo">GenInfo</string>
</resources>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res/sms.pack.sms0"
    android:id="@layout/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <TextView
        android:id="@+id/tvGenInfo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/sGenInfo" />    
</LinearLayout>

MainActivity.java

package sms.pack.sms0;

import android.util.Log;
import android.os.Bundle;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.view.Menu;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {
  private static final String TAG = "MainActivity";
  private static final String SMS_RECEIVED = "android.provider.Telephony.SMS_RECEIVED";
  TextView tvGenInfo;  
  public void appendGenInfo(String txt) {  
    Log.v(TAG, "genLog, txt=" + txt);
    txt = tvGenInfo.getText() + txt + "\r\n";
    tvGenInfo.setText(txt);
  }  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);    
    Log.v(TAG, "onCreate");
    tvGenInfo = (TextView) findViewById(R.id.tvGenInfo);    
    IntentFilter filter = new IntentFilter(Intent.ACTION_DEFAULT);
    filter.addAction(SMS_RECEIVED);
    filter.setPriority(1000);
    this.registerReceiver(this.smsReceiver, filter);    
    appendGenInfo("Created");
  }
  private BroadcastReceiver smsReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) { 
      Log.v(TAG, "smsReceiver.onReceive, " + "");
      Toast.makeText(context, "smsReceiver.onReceive, " + "", Toast.LENGTH_SHORT).show();
      System.out.println(TAG + ", smsReceiver.onReceive, " + "");
      Bundle bundle = intent.getExtras();
      if( bundle != null) {
        System.out.println(TAG + ", smsReceiver.onReceive.bundle, size=" + bundle.size());
        appendGenInfo(TAG + ", smsReceiver.onReceive.bundle, " + "bundle.size=" + bundle.size());//this works
      }
    }
  };   
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
  }
}