Android实现倒计时30分钟功能

以30分钟为例写的一个倒计时：
直接上代码

public class mainactivity extends appcompatactivity {

  private int minute = 30;//这是分钟
  private int second = 0;//这是分钟后面的秒数。这里是以30分钟为例的，所以，minute是30，second是0
  private textview timeview;
  private timer timer;
  private timertask timertask;
  //这是接收回来处理的消息
  private handler handler = new handler() {
    public void handlemessage(message msg) {
      if (minute == 0) {
        if (second == 0) {
          timeview.settext("time out !");
          if (timer != null) {
            timer.cancel();
            timer = null;
          }
          if (timertask != null) {
            timertask = null;
          }
        } else {
          second--;
          if (second >= 10) {
            timeview.settext("0" + minute + ":" + second);
          } else {
            timeview.settext("0" + minute + ":0" + second);
          }
        }
      } else {
        if (second == 0) {
          second = 59;
          minute--;
          if (minute >= 10) {
            timeview.settext(minute + ":" + second);
          } else {
            timeview.settext("0" + minute + ":" + second);
          }
        } else {
          second--;
          if (second >= 10) {
            if (minute >= 10) {
              timeview.settext(minute + ":" + second);
            } else {
              timeview.settext("0" + minute + ":" + second);
            }
          } else {
            if (minute >= 10) {
              timeview.settext(minute + ":0" + second);
            } else {
              timeview.settext("0" + minute + ":0" + second);
            }
          }
        }
      }
    }

  };


  @override
  protected void oncreate(bundle savedinstancestate) {
    requestwindowfeature(window.feature_no_title);
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_main);
    timeview = (textview) findviewbyid(r.id.tv);

    timeview.settext(minute + ":" + second);

    timertask = new timertask() {

      @override
      public void run() {
        message msg = new message();
        msg.what = 0;
        handler.sendmessage(msg);
      }
    };

    timer = new timer();
    timer.schedule(timertask, 0, 1000);

  }

  @override
  protected void ondestroy() {
    if (timer != null) {
      timer.cancel();
      timer = null;
    }
    if (timertask != null) {
      timertask = null;
    }
    minute = -1;
    second = -1;
    super.ondestroy();
  }

  @override
  protected void onstart() {
    super.onstart();
  }

  @override
  protected void onstop() {
    super.onstop();
  }

  @override
  protected void onresume() {
    super.onresume();
  }

  @override
  protected void onrestart() {
    super.onrestart();
  }

  @override
  protected void onpause() {
    super.onpause();
  }
}

ok，这就完成了。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。