我的PhoneStateListener没有被调用来显示信号强度

Question

我想显示当前的信号强度和当前的细胞ID和Lac在我的应用程序3g网络。由于它必须兼容API-8，因此我使用android.telephony的SignalStrength类。当我点击一个按钮时，现在我想让它显示当前单元的CID，Lac和信号强度。我得到的CID和LAC但信号强度始终显示为0。下面的代码给出：

public void onClick(View v) { 
    switch (v.getId()) { 
    case R.id.bShowCell: 
     GsmCellLocation location; 
     String cellID = ""; 
     String lac = ""; 
     Context context = (Context) getApplicationContext(); 
     TelephonyManager tm = (TelephonyManager) context 
       .getSystemService(Context.TELEPHONY_SERVICE); 
     location = (GsmCellLocation) tm.getCellLocation(); 
     cellID = String.valueOf(location.getCid()); 
     lac = String.valueOf(location.getLac()); 
     CurCell.setText(cellID); 
     CellLac.setText(lac); 
     CurStrgth.setText(getRSSI()); 
    } 
} 

public String getRSSI() { 
    MyListener = new MyPhoneStateListener(); 
    Tel = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE); 
    Tel.listen(MyListener, PhoneStateListener.LISTEN_SIGNAL_STRENGTHS); 
    String strength = MyListener.getStrength(); 
    return strength; 
} 

class MyPhoneStateListener extends PhoneStateListener { 

    public int singalStrengths; 

    @Override 
    public void onSignalStrengthsChanged(SignalStrength signalStrength) { 
     super.onSignalStrengthsChanged(signalStrength); 
     int asu = signalStrength.getGsmSignalStrength(); 
     singalStrengths = -113 + 2 * asu; 
    } 

    public String getStrength() { 
     return String.valueOf(singalStrengths); 
    } 
} 

我在网上查很多例子，我想我的代码是好的。但是当我在调试模式下检查它时，我发现当我点击按钮时，程序永远不会进入onSignalStrengthsChanged。有什么我失踪？

Answer 1

嗯，这是我以后的尝试，它工作正常。我必须使CurStrgth.setText（）独立于Button和PhoneStateListener内部，并从OnCreate（）方法调用侦听器。它工作正常，每当它获得信号强度的变化时更新CurStrgth TextView。我下面的代码给出：

public class MainActivity extends Activity implements OnClickListener { 


TextView CurStrgth; 
MyPhoneStateListener MyListener; 
TelephonyManager Tel; 

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

    CurStrgth = (TextView) findViewById(R.id.tvCurCellStrength); 

    MyListener = new MyPhoneStateListener(); 

    Tel = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE); 
    Tel.listen(MyListener, PhoneStateListener.LISTEN_SIGNAL_STRENGTHS); 


} 


@Override 
protected void onPause() { 
    super.onPause(); 
    Tel.listen(MyListener, PhoneStateListener.LISTEN_NONE); 
} 

@Override 
protected void onResume() { 
    super.onResume(); 
    Tel.listen(MyListener, PhoneStateListener.LISTEN_SIGNAL_STRENGTHS); 
} 

private class MyPhoneStateListener extends PhoneStateListener { 
    String gsmStrength = ""; 

    @Override 
    public void onSignalStrengthsChanged(SignalStrength signalStrength) { 
     super.onSignalStrengthsChanged(signalStrength); 
      gsmStrength = String 
       .valueOf(signalStrength.getGsmSignalStrength() * 2 - 113); 
     CurStrgth.setText(MyListener.getStrength() + "dBm"); 
    } 

    public String getStrength() { 
     return gsmStrength; 
    } 

} 
} 

现在，我检查只是调用

CurStrgth.setText(MyListener.getStrength() + "dBm"); 

一个按钮的OnClick（）方法中，它显示了一次性的价值，但如果我以后按下按钮它从不更新力量并不断显示初始值。