Android自定义短信倒计时view流程分析

 import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import androidx.annotation.NonNull;
import com.juexing.payassistant.activity.login.RegisterActivity;
import java.lang.ref.WeakReference;
//待优化为了保存倒计时状态线程延迟一秒关闭所有的子线程
//qq也是如此
public class CountDownTimeView extends androidx.appcompat.widget.AppCompatButton {
  private static volatile int i=60;
  //用来保存倒计时时间的中转变量
  private static volatile int j=0;
  private static TimeHandler handler;
//每次启动活动判断i是否为0来读取倒计时时间
  public static int getI() {
    return i;
  }
  //RegisterActivity是调用该控件的活动需要在oncreate中将对象传入
public void setActivity(RegisterActivity activity){
    handler=new TimeHandler(activity);
}
  public static void setI(int i) {
    CountDownTimeView.i = i;
  }
  //防止多次重复点击发送设置的变量
  private static volatile boolean send=true;
  private class TimeHandler extends Handler {
    WeakReference<RegisterActivity> timeActivityWeakReference;
 public TimeHandler(RegisterActivity registerActivity){
   this.timeActivityWeakReference = new WeakReference<>(registerActivity);
 }
    @Override
    public void handleMessage(@NonNull Message msg) {
      super.handleMessage(msg);
      RegisterActivity activity=timeActivityWeakReference.get();//获取活动
      switch (msg.what){
        case 1:
          if(i>0){
            activity.getmessage. setText(i+"s");
          }else {
          }
          break;
        case 2:
          activity.getmessage. setText("重新获取");
          break;
        case 3:
          i=j-1;
          j=0;
          send=false;
          handler.postDelayed(runnable,1000);
      }
    }
  };
  public CountDownTimeView(Context context) {
    super(context);
  }
  public CountDownTimeView(Context context, AttributeSet attrs) {
    super(context, attrs);
  }
//网络请求短信成功后调用
  public void onStart(CountDownTimeView view){
   if(send){
     if(i==0){
       i=60;
     }
     handler.postDelayed(runnable,1000);
     view.setText(i+"s");
     send=false;
   }else {
       //为了显示不突兀自动减去一秒
       view.setText(i-1+"s");
       j=i;
       //将i设置为0是将所有线程运行完毕关闭释放内存
       i=0;
       handler.removeCallbacksAndMessages(null);
       //因为线程调度随机性所以要延迟一秒发送保证子线程关闭
       Message message=Message.obtain();
       message.what=3;
       handler.sendMessageDelayed(message,1000);
//     i=j;
   }
  }
 //设置成静态保证唯一性
  public static Runnable runnable=new Runnable() {
    @Override
    public void run() {
      if(i>0){
        i--;
        Message message=new Message();
        message.what=1;
        handler.handleMessage(message);
        handler.postDelayed(runnable,1000);

      }else {
        if(j!=0){

        }else {
          send=true;
          Message message=new Message();
          message.what=2;
          handler.handleMessage(message);
        }

      }
    }
  };
}

 getmessage.setActivity(this);
    if(getmessage.getI()<60){
      if(getmessage.getI()>0){
        getmessage.onStart(getmessage);
      }else {
        getmessage.setText("重新获取");
      }

    }

  }