Android编程实现添加低电流提醒功能的方法

本文实例讲述了android编程实现添加低电流提醒功能的方法。分享给大家供大家参考，具体如下：

特殊需求，检测电流是否正常。

监听如下广播：

intent.action_battery_changed
plugtype = intent.getintextra(batterymanager.extra_plugged, 0);
if(mlowelectricityremind == null){
  mlowelectricityremind = new lowelectricityremind(batterymeterview.this.getcontext());
}
mlowelectricityremind.changeplugtype(plugtype);

添加lowelectricityremind类

package com.android.systemui;
import android.content.context;
import android.content.dialoginterface;
import android.os.batterymanager;
import android.os.handler;
import android.util.slog;
import java.io.bufferedreader;
import java.io.file;
import java.io.filenotfoundexception;
import java.io.filereader;
import java.io.ioexception;
import com.android.systemui.statusbar.phone.systemuidialog;
/**
 * add low electricity remind
 * created by fanlj on 2017-2-18.
 */
public class lowelectricityremind {
  private static final string tag = lowelectricityremind.class.getsimplename();
  private static final int low_electricity_remind_delayed = 50000;
  private static final long remind_interval = 3 * 1000 * 60; //three minutes
  private static final int max_current_count = 3;
  private static final boolean debug = true;
  private boolean isfirstinitialize = true;
  private context mcontext;
  private handler mhandler;
  private int[] mcurrent = new int[max_current_count];
  private file mcurrentnowfile = null;
  private systemuidialog mremiddialog;
  private long mlastplugcurrent = 0;
  private long mlastremindtime = 0; //if mremiddialog is showed, mlastremindtime != 0
  private boolean isignore = false;
  lowelectricityremind(context context){
    mcontext = context;
    mhandler = new handler();
    mcurrentnowfile = new file("/sys/class/power_supply/battery/current_now");
  }
  public void changeplugtype(int type){
    if(debug) {
      slog.e(tag, "change plug type to " + type);
    }
    mhandler.removecallbacks(lowelectricityremindrunnable);
    if(type == batterymanager.battery_plugged_ac || (debug && type == batterymanager.battery_plugged_usb)){
      if(debug) {
        slog.e(tag, "start runnable");
      }
      if(isfirstinitialize){
        isfirstinitialize = false;
      }
      mhandler.postdelayed(lowelectricityremindrunnable, low_electricity_remind_delayed);
    } else {
      cleanallcache();
    }
  }
  private runnable lowelectricityremindrunnable = new runnable() {
    @override
    public void run() {
      if(!needshowreminddialog(true)){
        postdelayed();
        return;
      }
      boolean isfull = true;
      int cbattnow = readcurrent();
      if(mlastplugcurrent == cbattnow){
        postdelayed();
        return;
      }
      mlastplugcurrent = cbattnow;
      if(mcurrent[max_current_count - 1] != 0){
        int minindex = 0;
        int maxindex = 0;
        for (int i = max_current_count; i > 1; i--){
          int curr = mcurrent[i];
          if(mcurrent[minindex] > curr){
            minindex = i;
          }
          if(mcurrent[maxindex] < curr){
            maxindex = i;
          }
        }
        if(cbattnow < 0){ //in the charging
          int min = mcurrent[minindex];
          int max = mcurrent[maxindex];
          if((min < 0 && min < cbattnow) || (min > 0 && min > cbattnow)){ //-1600 < -1400 900 > 800 if true, replace min value.
            mcurrent[minindex] = cbattnow;
          } else if((max < 0 && max < cbattnow) || (max > 0 && max > cbattnow)){ //-1600 < -1400 900 > 800
            mcurrent[maxindex] = cbattnow;
          }
        }
      } else {
        for (int i = 0; i < max_current_count; i++){
          if(mcurrent[i] == 0){
            mcurrent[i] = cbattnow;
            if(i != max_current_count - 1) {
              isfull = false;
            } else {
              isfull = true;
            }
            break;
          }
        }
      }
      //if(isfull && needshowreminddialog(false)){
      if(isfull && needshowreminddialog(true)){
        if(mremiddialog == null){
          mremiddialog = new systemuidialog(mcontext);
          mremiddialog.settitle(r.string.charge_current_warning_title);
          mremiddialog.setpositivebutton(r.string.charge_current_warning_yes, null);
          mremiddialog.setnegativebutton(r.string.charge_current_warning_ignore, new dialoginterface.onclicklistener() {
            @override
            public void onclick(dialoginterface dialog, int which) {
              isignore = true;
            }
          });
        }
        if(debug && mremiddialog.isshowing()){
          mremiddialog.dismiss();
        }
        if(!mremiddialog.isshowing()){
          string message = mcontext.getstring(r.string.charge_current_warning_content);
          if(debug){
            message += "\n";
            for (int i = 0; i < max_current_count; i++){
              message += mcurrent[i];
              message += "  ";
            }
          }
          mremiddialog.setmessage(message);
          mremiddialog.show();
        }
        //clean all save
        cleanallcache();
        mlastremindtime = system.currenttimemillis();
      }
      postdelayed();
    }
  };
  private void postdelayed(){
    mhandler.removecallbacks(lowelectricityremindrunnable);
    mhandler.postdelayed(lowelectricityremindrunnable, low_electricity_remind_delayed);
  }
  private void cleanallcache(){
    for (int i = 0; i < max_current_count; i++){
      mcurrent[i] = 0;
    }
    mlastplugcurrent = 0;
  }
  /**
   * read battery current
   * @return battery current
   */
  private int readcurrent(){
    int cbattnow = 0;
    filereader filereader;
    bufferedreader br;
    try {
      filereader = new filereader(mcurrentnowfile);
      br = new bufferedreader(filereader);
      cbattnow = integer.parseint(br.readline());
      cbattnow = cbattnow / 1000;  //ua to ma
      br.close();
      filereader.close();
      if(debug) {
        slog.e(tag, "last plug current : " + cbattnow);
      }
    } catch (filenotfoundexception e) {
      slog.e(tag, "failure in reading battery current", e);
    } catch (ioexception e) {
      slog.e(tag, "failure in reading battery current", e);
    }
    return cbattnow;
  }
  private boolean needshowreminddialog(boolean filterdata){
    if(isignore){
      return false;
    }
    boolean isneedshow = true;
    if(!filterdata){
      for (int i = 0; i < max_current_count; i++){
        if(mcurrent[i] <= 0){
          isneedshow = false;
          break;
        }
      }
    }
    if(isneedshow){
      long currtime = system.currenttimemillis();
      if(debug){
        slog.e(tag, "mlastremindtime = " + mlastremindtime + "  currtime = " + currtime);
      }
      if(mlastremindtime == 0){
        isneedshow = true;
      } else if(mlastremindtime + remind_interval <= currtime){
        isneedshow = true;
      } else{
        isneedshow = false;
      }
    }
    if(debug){
      slog.e(tag, "need show remind dialog = " + isneedshow);
    }
    return isneedshow;
  }
}

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希望本文所述对大家android程序设计有所帮助。