Android2.3之前的系统可以通过反射机制调用ITelephone的方法来挂断电话，因为Android2.3以后增加了对permission  android.permission.MODIFY_PHONE_STATE 的限制，之前的反射的方法不能用了，我们可以通过发送广播的方式来接听电话。

示例代码

package com.example.android_3gtest;import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import android.content.Context;
import android.content.Intent;
import android.media.AudioManager;
import android.net.Uri;
import android.os.Build;
import android.telephony.TelephonyManager;
import android.text.TextUtils;
import android.view.KeyEvent;public class PhoneUtil {public static String TAG = PhoneUtil.class.getSimpleName();  /*** 挂断电话* @param context*/public static void endCall(Context context) {  try {  Object telephonyObject = getTelephonyObject(context);  if (null != telephonyObject) {  Class telephonyClass = telephonyObject.getClass();  Method endCallMethod = telephonyClass.getMethod("endCall");  endCallMethod.setAccessible(true);  endCallMethod.invoke(telephonyObject);  }  } catch (SecurityException e) {  e.printStackTrace();  } catch (NoSuchMethodException e) {  e.printStackTrace();  } catch (IllegalArgumentException e) {  e.printStackTrace();  } catch (IllegalAccessException e) {  e.printStackTrace();  } catch (InvocationTargetException e) {  e.printStackTrace();  }  }  private static Object getTelephonyObject(Context context) {  Object telephonyObject = null;  try {  // 初始化iTelephony  TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);  // Will be used to invoke hidden methods with reflection  // Get the current object implementing ITelephony interface  Class telManager = telephonyManager.getClass();  Method getITelephony = telManager.getDeclaredMethod("getITelephony");  getITelephony.setAccessible(true);  telephonyObject = getITelephony.invoke(telephonyManager);  } catch (SecurityException e) {  e.printStackTrace();  } catch (NoSuchMethodException e) {  e.printStackTrace();  } catch (IllegalArgumentException e) {  e.printStackTrace();  } catch (IllegalAccessException e) {  e.printStackTrace();  } catch (InvocationTargetException e) {  e.printStackTrace();  }  return telephonyObject;  }  /*** 通过反射调用的方法，接听电话，该方法只在android 2.3之前的系统上有效。* @param context*/  private static void answerRingingCallWithReflect(Context context) {  try {  Object telephonyObject = getTelephonyObject(context);  if (null != telephonyObject) {  Class telephonyClass = telephonyObject.getClass();  Method endCallMethod = telephonyClass.getMethod("answerRingingCall");  endCallMethod.setAccessible(true);  endCallMethod.invoke(telephonyObject);  // ITelephony iTelephony = (ITelephony) telephonyObject;  // iTelephony.answerRingingCall();  }  } catch (SecurityException e) {  e.printStackTrace();  } catch (IllegalArgumentException e) {  e.printStackTrace();  } catch (IllegalAccessException e) {  e.printStackTrace();  } catch (InvocationTargetException e) {  e.printStackTrace();  } catch (NoSuchMethodException e) {  e.printStackTrace();  }  }  /*** 伪造一个有线耳机插入，并按接听键的广播，让系统开始接听电话。* @param context*/  private static void answerRingingCallWithBroadcast(Context context){  AudioManager localAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);  //判断是否插上了耳机  boolean isWiredHeadsetOn = localAudioManager.isWiredHeadsetOn();  if (!isWiredHeadsetOn) {  Intent headsetPluggedIntent = new Intent(Intent.ACTION_HEADSET_PLUG);  headsetPluggedIntent.putExtra("state", 1);  headsetPluggedIntent.putExtra("microphone", 0);  headsetPluggedIntent.putExtra("name", "");  context.sendBroadcast(headsetPluggedIntent);  Intent meidaButtonIntent = new Intent(Intent.ACTION_MEDIA_BUTTON);  KeyEvent keyEvent = new KeyEvent(KeyEvent.ACTION_UP, KeyEvent.KEYCODE_HEADSETHOOK);  meidaButtonIntent.putExtra(Intent.EXTRA_KEY_EVENT,keyEvent);  context.sendOrderedBroadcast(meidaButtonIntent, null);  Intent headsetUnpluggedIntent = new Intent(Intent.ACTION_HEADSET_PLUG);  headsetUnpluggedIntent.putExtra("state", 0);  headsetUnpluggedIntent.putExtra("microphone", 0);  headsetUnpluggedIntent.putExtra("name", "");  context.sendBroadcast(headsetUnpluggedIntent);  } else {  Intent meidaButtonIntent = new Intent(Intent.ACTION_MEDIA_BUTTON);  KeyEvent keyEvent = new KeyEvent(KeyEvent.ACTION_UP, KeyEvent.KEYCODE_HEADSETHOOK);  meidaButtonIntent.putExtra(Intent.EXTRA_KEY_EVENT,keyEvent);  context.sendOrderedBroadcast(meidaButtonIntent, null);  }  }  /*** 接听电话* @param context*/  public static void answerRingingCall(Context context) {  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {	//2.3或2.3以上系统answerRingingCallWithBroadcast(context);  } else {  answerRingingCallWithReflect(context);  }  }  /*** 打电话* @param context* @param phoneNumber*/  public static void callPhone(Context context, String phoneNumber) {  if(!TextUtils.isEmpty(phoneNumber)){  try {  Intent callIntent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:"+ phoneNumber));  context.startActivity(callIntent);  } catch (Exception e) {  e.printStackTrace();  }  }  }  /*** 拨电话* @param context* @param phoneNumber*/  public static void dialPhone(Context context, String phoneNumber){  if(!TextUtils.isEmpty(phoneNumber)){  try {  Intent callIntent = new Intent(Intent.ACTION_DIAL, Uri.parse("tel:"+ phoneNumber));  context.startActivity(callIntent);  } catch (Exception e) {  e.printStackTrace();  }  }  }  
}