Android问题记录

Messenger 是基于消息(Message)的进程间通信方式。使用Messenger为服务创建接口，服务可以这种方式定义对应于不同类型Message对象的Handler，此Handler是Messenger的基础，Messenger随后可与客户端分享一个IBinder，从而让客户端能利用Message对象向服务发送命令。客户端还可以自定义Messenger来实现双向通信。

客户端

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@Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      Intent intent = new Intent(this, XxxService.class);
      bindService(intent, mMessengerConnection, BIND_AUTO_CREATE);
  }

  private static final int MSG_ID_CLIENT = 1;
  private static final int MSG_ID_SERVER = 2;
  private static final String MSG_CONTENT = "getAddress";
  /**
   * 客户端的 Messenger
   */
  Messenger mClientMessenger = new Messenger(new Handler() {
      @Override
      public void handleMessage(final Message msg) {
          if (msg != null && msg.arg1 == MSG_ID_SERVER) {
              if (msg.getData() == null) {
                  return;
              }
              Map<String, Integer> locationMap= (Map<String, Integer>) msg.getData().get(MSG_CONTENT);
              Log.e("IPC", "Message from server: " + locationMap.size());
              prepareShow(locationMap);
          }
      }
  });

  //服务端的 Messenger
  private Messenger mServerMessenger;

  private ServiceConnection mMessengerConnection = new ServiceConnection() {
      @Override
      public void onServiceConnected(final ComponentName name, final IBinder service) {
          mServerMessenger = new Messenger(service);

          Message message = Message.obtain();
          message.arg1 = MSG_ID_CLIENT;
          Bundle bundle = new Bundle();
          bundle.putString(MSG_CONTENT, "测试信息");
          message.setData(bundle);
          message.replyTo = mClientMessenger;     //指定回信人是客户端定义的

          try {
              mServerMessenger.send(message);
          } catch (RemoteException e) {
              e.printStackTrace();
          }

      }

      @Override
      public void onServiceDisconnected(final ComponentName name) {
          mServerMessenger = null;
      }
  };


服务端

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private static final int MSG_ID_CLIENT = 1;
private static final int MSG_ID_SERVER = 2;
private static final String MSG_CONTENT = "getAddress";
private Messenger clientMessager = null;
// private Message clientMessage = null;


Messenger mMessenger = new Messenger(new Handler() {
    @Override
    public void handleMessage(Message msg) {
        if (msg != null && msg.arg1 == MSG_ID_CLIENT) {
            clientMessager = msg.replyTo;
            // clientMessage=msg
            getDataFromClient();
        }
    }
});

public void getDataFromClient() {
   if (mMessage.getData() == null) {
       return;
   }
   String content = (String) mMessage.getData().get(MSG_CONTENT);  //接收客户端的消息
   Log.e("IPC", "Message from client: " + content);
}

public void sendDataToClient(Map<String, Integer> locationMap) {
    //回复消息给客户端
    Message replyMsg = Message.obtain();
    replyMsg.arg1 = MSG_ID_SERVER;
    Bundle bundle = new Bundle();
    bundle.putSerializable(MSG_CONTENT, (Serializable) locationMap);
    replyMsg.setData(bundle);

    try {
        // clientMessage.replyTo.send(replyMsg);
        clientMessager.send(replyMsg);     //回信
    } catch (RemoteException e) {
        e.printStackTrace();
    }
}

@Nullable
@Override
public IBinder onBind(Intent intent) {
    return mMessenger.getBinder();
}

服务端被注释掉的这些代码如果在使用时会发生clientMessage.replyTo中的replyTo对象为Null的情况，但是如果在Handler中直接获取replyTo对象就没问题。

猜测Message的成员对象replyTo在离开Handler时如果没有被引用生命周期结束，有空再研究。

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//private Message clientMessage
// clientMessage=msg
// clientMessage.replyTo.send(replyMsg);

参考文献
Android进程间通信之Messenger
Android 进阶10：进程通信之 Messenger 使用与解析

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Android获取蓝牙MAC地址

谷歌文档：
为给用户提供更严格的数据保护，从此版本开始，对于使用 WLAN API 和 Bluetooth API 的应用，Android 移除了对设备本地硬件标识符的编程访问权。WifiInfo.getMacAddress() 方法和 BluetoothAdapter.getAddress() 方法现在会返回常量值 02:00:00:00:00:00。

手动填写 设置-》全部参数-》状态信息-》可以获取到

！！！！！！！！！！！！！！！！！！！！！！！！！下面的方法在某些手机上失效了！！！！！！！！！！！！！！！！！！！！！！！

不严谨的拿了几个手机看了下WIFI MAC地址和蓝牙MAC地址，发现蓝牙MAC地址比WIFI MAC地址小1,因此尝试使用WIFI MAC地址计算蓝牙的MAC地址。（未经过大范围设备测试，这里的方法不严谨）

先使用传统方法获取蓝牙MAC地址，如果失败了，就使用WIFI MAC地址计算（不严谨）。

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import android.bluetooth.BluetoothAdapter;
import android.content.Context;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.os.Build;
import android.text.TextUtils;
import android.util.Log;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.NetworkInterface;
import java.util.Collections;
import java.util.List;
import java.util.Locale;

public class MacAddress {

    public static String getBluetoothMAC(Context context) {
        String mac = MacAddress.getBtAddressByReflection();
        if (mac != null) {
            Log.e("Bluetooth MAC address:", mac);
        } else {
            mac = MacAddress.getMacAddress(context);
            String prefix = mac.substring(0, 15);
            String sufix = mac.substring(15, 17);
            Integer value = Integer.parseInt(sufix, 16);
            value--;
            sufix = value.toHexString(value);
            mac = prefix + sufix.toUpperCase();
            Log.e("Bluetooth MAC address:", mac);
        }
        return mac;

    }

    public static String getMacAddress(Context context) {
        String mac = "02:00:00:00:00:00";
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
            mac = getMacDefault(context);
        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
            mac = getMacFromFile();
        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            mac = getMacFromHardware();
        }
        return mac;
    }


    public static String getBtAddressByReflection() {
        BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        Field field = null;
        try {
            field = BluetoothAdapter.class.getDeclaredField("mService");
            field.setAccessible(true);
            Object bluetoothManagerService = field.get(bluetoothAdapter);
            if (bluetoothManagerService == null) {
                return null;
            }
            Method method = bluetoothManagerService.getClass().getMethod("getAddress");
            if (method != null) {
                Object obj = method.invoke(bluetoothManagerService);
                if (obj != null) {
                    return obj.toString();
                }
            }
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        return null;
    }


    /**
     * Android  6.0 之前（不包括6.0）
     * 必须的权限  <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
     *
     * @param context
     * @return
     */
    private static String getMacDefault(Context context) {
        String mac = "02:00:00:00:00:00";
        if (context == null) {
            return mac;
        }

        WifiManager wifi = (WifiManager) context.getApplicationContext()
                .getSystemService(Context.WIFI_SERVICE);
        if (wifi == null) {
            return mac;
        }
        WifiInfo info = null;
        try {
            info = wifi.getConnectionInfo();
        } catch (Exception e) {
        }
        if (info == null) {
            return null;
        }
        mac = info.getMacAddress();
        if (!TextUtils.isEmpty(mac)) {
            mac = mac.toUpperCase(Locale.ENGLISH);
        }
        return mac;
    }

    /**
     * Android 6.0（包括） - Android 7.0（不包括）
     *
     * @return
     */
    private static String getMacFromFile() {
        String WifiAddress = "02:00:00:00:00:00";
        try {
            WifiAddress = new BufferedReader(new FileReader(new File("/sys/class/net/wlan0/address"))).readLine();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return WifiAddress;
    }

    /**
     * 遍历循环所有的网络接口，找到接口是 wlan0
     * 必须的权限 <uses-permission android:name="android.permission.INTERNET" />
     *
     * @return
     */
    private static String getMacFromHardware() {
        try {
            List<NetworkInterface> all = Collections.list(NetworkInterface.getNetworkInterfaces());
            for (NetworkInterface nif : all) {
                if (!nif.getName().equalsIgnoreCase("wlan0")) continue;

                byte[] macBytes = nif.getHardwareAddress();
                if (macBytes == null) {
                    return "";
                }

                StringBuilder res1 = new StringBuilder();
                for (byte b : macBytes) {
                    res1.append(String.format("%02X:", b));
                }

                if (res1.length() > 0) {
                    res1.deleteCharAt(res1.length() - 1);
                }
                return res1.toString();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "02:00:00:00:00:00";
    }
}


参考文献
Android 版本兼容 — Android 6.0 和 7.0后获取Mac地址

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安卓平添AAChartModel pie chart添加动态数据

安卓平添AAChartModel pie chart添加动态数据

开发者没有给动态数据的示例，某些图的动态数据设置需要思考一下，转换成Object[]类型

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public void showChart(Object[][] data) {
    AAChartModel aaChartModel = new AAChartModel()
            .chartType(AAChartType.Pie)
            .backgroundColor("#ffffff")
            .title("14天内到访地点")
            .subtitle("")
            .dataLabelsEnabled(true)//是否直接显示扇形图数据
            .yAxisTitle("℃")
            .series(new AAPie[]{
                    new AAPie()
                            .name("到访地点")
                            .innerSize("20%")
                            .size(150f)
                            .dataLabels(new AADataLabels()
                                    .enabled(true)
                                    .useHTML(true)
                                    .distance(5f)
                                    .format("<b>{point.name}</b>: <br> {point.percentage:.1f} %"))
                            .data(data),
            });
    //The chart view object calls the instance object of AAChartModel and draws the final graphic
    aaChartView.aa_drawChartWithChartModel(aaChartModel);
}

pie chart需要传入的data数据是Object[]类型的，开发者给的Demo中的数据是写死的,如下：

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new AAChartModel()
             .chartType(AAChartType.Pie)
             .backgroundColor("#ffffff")
             .title("LANGUAGE MARKET SHARES JANUARY,2020 TO MAY")
             .subtitle("virtual data")
             .dataLabelsEnabled(true)//是否直接显示扇形图数据
             .yAxisTitle("℃")
             .series(new AAPie[] {
                     new AAPie()
                             .name("Language market shares")
                             .innerSize("20%")
                             .size(150f)
                             .dataLabels(new AADataLabels()
                                     .enabled(true)
                                     .useHTML(true)
                                     .distance(5f)
                                     .format("<b>{point.name}</b>: <br> {point.percentage:.1f} %"))
                             .data(new Object[][] {
                             {"Java"  ,67},
                             {"Swift",999},
                             {"Python",83},
                             {"OC"    ,11},
                             {"Go"    ,30},
                     })
                     ,
                     }
             );

java中如果使用Map保存数据那么数据预处理方法如下：

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public Object[][] processRawData() {

    Object[][] data = new Object[locationMap.size()][2];
    int index = 0;
    for (Map.Entry<String, Integer> entry : locationMap.entrySet()) {
        data[index][0] = entry.getKey();
        data[index][1] = entry.getValue();
    }
    return data;
}

其中locationMap为java中的Map数据，将其替换成自己的Map就可以了

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tag:

    缺失模块。
    1、请确保node版本大于6.2
    2、在博客根目录（注意不是yilia根目录）执行以下命令：
    npm i hexo-generator-json-content --save

    3、在根目录_config.yml里添加配置： 

      jsonContent:
    meta: false
    pages: false
    posts:
      title: true
      date: true
      path: true
      text: false
      raw: false
      content: false
      slug: false
      updated: false
      comments: false
      link: false
      permalink: false
      excerpt: false
      categories: false
      tags: true

我是一只<br>又水又笨又菜的<br>菜狗子<br>希望有一天被领走