在到达某个位置时在 Android 中发送短信

Posted 2023-02-19

【中文标题】在到达某个位置时在 Android 中发送短信

【英文标题】：Sending Sms in Android on reaching a Location

【发布时间】：2017-08-09 06:59:45

【问题描述】：

我是 android 的绝对初学者。在这段代码中，我想在到达特定位置时发送短信。如果我将短信管理器放在 onlocationchange() 函数之外，我的应用程序会崩溃。所以如果我没有离开 10 米的距离，它会发送连续的短信。我只想让它只发送一条短信。请帮忙！！

MainActivity.java

    protected void onCreate(Bundle savedInstanceState) 
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    txtLat = (TextView) findViewById(R.id.textview1);

    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    try 
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0,10, this);
     catch (SecurityException e)
    
        txtLat = (TextView) findViewById(R.id.textview1);
        txtLat.setText("Security Exception");

    


@Override
public void onLocationChanged(Location location) 
    txtLat = (TextView) findViewById(R.id.textview1);
    txtLat.setText("Latitude:" + location.getLatitude() + ", Longitude:" + location.getLongitude());
    float dist1=getsignaldistance(location);
    tx=(TextView)findViewById((R.id.textview2));
    tx.setText("Distance for next signal:"+Float.toString(dist1)+"m");
    checksendsms(location);


private void checksendsms(Location location) 
    Location strpoint=new Location("strpoint");
    strpoint.setLatitude(location.getLatitude());
    strpoint.setLongitude(location.getLongitude());
    Location endpoint=new Location("endpoint");
    endpoint.setLatitude(10.813763);
    endpoint.setLongitude(78.644309);
    float dist=strpoint.distanceTo(endpoint);
    tx=(TextView)findViewById((R.id.textview3));
    tx.setText("Distance between points:"+Float.toString(dist)+"m");
    if(dist<=10.0)
    
        SmsManager sms = SmsManager.getDefault();
        sms.sendTextMessage(phonenumber, null, message, null, null);
        finish();
    

【问题讨论】：

您需要保留一个标志（布尔值），指示短信是否已发送。

【参考方案1】：

您需要保留一个标志（布尔值）来指示短信是否已发送。

private boolean mHasSmsBeenSent = false; // <--- HERE

protected void onCreate(Bundle savedInstanceState) 
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    txtLat = (TextView) findViewById(R.id.textview1);

    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    try 
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0,10, this);
     catch (SecurityException e)
    
        txtLat = (TextView) findViewById(R.id.textview1);
        txtLat.setText("Security Exception");

    


@Override
public void onLocationChanged(Location location) 
    txtLat = (TextView) findViewById(R.id.textview1);
    txtLat.setText("Latitude:" + location.getLatitude() + ", Longitude:" + location.getLongitude());
    float dist1=getsignaldistance(location);
    tx=(TextView)findViewById((R.id.textview2));
    tx.setText("Distance for next signal:"+Float.toString(dist1)+"m");
    if(!mSmsHasBeenSent)         // <-- HERE
        checksendsms(location);
    


private void checksendsms(Location location) 
    Location strpoint=new Location("strpoint");
    strpoint.setLatitude(location.getLatitude());
    strpoint.setLongitude(location.getLongitude());
    Location endpoint=new Location("endpoint");
    endpoint.setLatitude(10.813763);
    endpoint.setLongitude(78.644309);
    float dist=strpoint.distanceTo(endpoint);
    tx=(TextView)findViewById((R.id.textview3));
    tx.setText("Distance between points:"+Float.toString(dist)+"m");
    if(dist<=10.0)
    
        SmsManager sms = SmsManager.getDefault();
        sms.sendTextMessage(phonenumber, null, message, null, null);
        mHasSmsBeenSent = true; // <--- HERE
        finish();
    

【讨论】：

哎呀一个错误！谢谢你解决了我的问题！！

【参考方案2】：

你好去掉Activity的onDestroy中的位置回调..

protected void onCreate(Bundle savedInstanceState) 
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    txtLat = (TextView) findViewById(R.id.textview1);

    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    try 
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0,10, this);
     catch (SecurityException e)
    
        txtLat = (TextView) findViewById(R.id.textview1);
        txtLat.setText("Security Exception");

    


@Override
protected void onDestroy() 
    super.onDestroy();
    locationManager.removeUpdates(this);



@Override
public void onLocationChanged(Location location) 
    txtLat = (TextView) findViewById(R.id.textview1);
    txtLat.setText("Latitude:" + location.getLatitude() + ", Longitude:" + location.getLongitude());
    float dist1=getsignaldistance(location);
    tx=(TextView)findViewById((R.id.textview2));
    tx.setText("Distance for next signal:"+Float.toString(dist1)+"m");
    checksendsms(location);


private void checksendsms(Location location) 
    Location strpoint=new Location("strpoint");
    strpoint.setLatitude(location.getLatitude());
    strpoint.setLongitude(location.getLongitude());
    Location endpoint=new Location("endpoint");
    endpoint.setLatitude(10.813763);
    endpoint.setLongitude(78.644309);
    float dist=strpoint.distanceTo(endpoint);
    tx=(TextView)findViewById((R.id.textview3));
    tx.setText("Distance between points:"+Float.toString(dist)+"m");
    if(dist<=10.0)
    
        SmsManager sms = SmsManager.getDefault();
        sms.sendTextMessage(phonenumber, null, message, null, null);
        finish();
    

【讨论】：

非常感谢您的帮助！