基于Android实现答题倒计时功能

package com.zking.sun.dao;

import android.support.v4.app.Fragment;
import android.util.Log;

/**
 * Created by sun on 2017/1/11.
 */

public abstract class LazyFragment extends Fragment {
  protected boolean isVisible;
  /**
   * 在这里实现Fragment数据的缓加载.
   * @param isVisibleToUser
   */
  @Override
  public void setUserVisibleHint(boolean isVisibleToUser) {
    super.setUserVisibleHint(isVisibleToUser);
    if(getUserVisibleHint()) {
      //可见时调用
      isVisible = true;
      onVisible();
    } else {
      isVisible = false;
      onInvisible();
    }
  }
  protected abstract void onVisible();
  //protected abstract void lazyLoad();
  protected abstract void onInvisible();
}

package com.zking.sun.android_06_project;

import android.content.Intent;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.os.Handler;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;

import com.zking.sun.dao.LazyFragment;
import com.zking.sun.dao.QusetionDao;
import com.zking.sun.entity.QuestionEntity;

import java.util.List;

import static com.zking.sun.android_06_project.R.id.tv_splash_01;

/**
 * Created by sun on 2016/12/21.
 */

public class FragmentActivity extends LazyFragment {
  private ViewPager viewpager_main_01;
  private TextView question_fragment_tv;
  private RadioButton answer_fragment_01,answer_fragment_02,answer_fragment_03,answer_fragment_04;
  private QusetionDao qusetiOnDao=new QusetionDao();
  private int i;
  private RadioGroup rg_fragment_qu;
  private String right_answer;
  private TextView count_fragment_down;
  private int SPLASH_DISPLAY_LENGHT = 10000; //延迟多少秒
  private TextView tv_splash_01;
  private Handler handler = new Handler();
  private Runnable runnbale ;
  private Intent intent;
  private MyCountdownTimer countdowntimer;
  private TextView questionR_fragment_tv;
  private boolean isPrepared;

  public FragmentActivity(){
  }
  public FragmentActivity(int i){
    this.i=i;
  }
  public int getI() {
    return i;
  }
  public void setI(int i) {
    this.i = i;
  }


  @Nullable
  @Override
  public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v=inflater.inflate(R.layout.fragment_1,null);
    //找到问题和答案的控件 
    question_fragment_tv = (TextView) v.findViewById(R.id.question_fragment_tv);
    questionR_fragment_tv = (TextView) v.findViewById(R.id.questionR_fragment_tv);
    questionR_fragment_tv.setVisibility(View.INVISIBLE);
    answer_fragment_01 = (RadioButton) v.findViewById(R.id.answer_fragment_01);
    answer_fragment_02 = (RadioButton) v.findViewById(R.id.answer_fragment_02);
    answer_fragment_03 = (RadioButton) v.findViewById(R.id.answer_fragment_03);
    answer_fragment_04 = (RadioButton) v.findViewById(R.id.answer_fragment_04);
    rg_fragment_qu = (RadioGroup) v.findViewById(R.id.rg_fragment_qu);
    count_fragment_down = (TextView) v.findViewById(R.id.count_fragment_down);
    //倒计时
    countdowntimer = new MyCountdownTimer(10000, 1000);
    //绑定值 获取页面的监听的i 传过来改变
    isPrepared = true;
    //懒加载
    getvalue(this.i);
    onVisible();//可见
    onInvisible();//不可见
    // lazyLoad();

    return v;
  }


  public void getvalue(int i){
    //查询数据
    /**
     * @param context 上下文
     * @param name  名字（数据库名），文件名
     * @param factory 游标工厂，多数情况：null
     * @param version 数据库版本
     */
    //DBHepler dbHepler=new DBHepler(this,"questions.db",null,1);
    List questiOnEntityList=qusetionDao.findAll(getContext());
    right_answer = questionEntityList.get(i).getRight_answer();
    questionR_fragment_tv.setText("答案："+right_answer);
    /* if (right_answer.equalsIgnoreCase("A")){
      right_answer = "answer_fragment_01";
    }*/


    //将查询出来的数据放到控件里面
    question_fragment_tv.setText(questionEntityList.get(i).getQusetion());
    answer_fragment_01.setText(questionEntityList.get(i).getAnswera());
    answer_fragment_02.setText(questionEntityList.get(i).getAnswerb());
    answer_fragment_03.setText(questionEntityList.get(i).getAnswerc());

    String this04=questionEntityList.get(i).getAnswerd()+"";
    Log.i("answer_fragment_04","_____________"+this04+"_____________");
    if(this04.equals("")||this04.equals("null")){
      answer_fragment_04.setVisibility(View.INVISIBLE);
    }
    else{
      answer_fragment_04.setText(questionEntityList.get(i).getAnswerd());
      answer_fragment_04.setVisibility(View.VISIBLE);
    }



    //get组设点击事件
    rg_fragment_qu.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
      @Override
      public void onCheckedChanged(RadioGroup group, int checkedId) {
        rg_fragment_qu.setEnabled(false);
        int selectRadio = group.getCheckedRadioButtonId();
        switch (selectRadio){
          case R.id.answer_fragment_01:
            // countdowntimer.cancel();
            if (right_answer.equalsIgnoreCase("A")){
              answer_fragment_01.setBackgroundResource(R.drawable.examtxt_btn_right);
            }
            else{
              answer_fragment_01.setBackgroundResource(R.drawable.examtxt_btn_wrong);
              questionR_fragment_tv.setVisibility(View.VISIBLE);
            }
            answer_fragment_02.setEnabled(false);
            answer_fragment_03.setEnabled(false);
            answer_fragment_04.setEnabled(false);
            break;
          case R.id.answer_fragment_02:
            //countdowntimer.cancel();
            if (right_answer.equalsIgnoreCase("B")){
              answer_fragment_02.setBackgroundResource(R.drawable.examtxt_btn_right);
            }
            else{
              answer_fragment_02.setBackgroundResource(R.drawable.examtxt_btn_wrong);
              questionR_fragment_tv.setVisibility(View.VISIBLE);
            }
            answer_fragment_01.setEnabled(false);
            answer_fragment_03.setEnabled(false);
            answer_fragment_04.setEnabled(false);
            break;
          case R.id.answer_fragment_03:
            //countdowntimer.cancel();
            if (right_answer.equalsIgnoreCase("C")){
              answer_fragment_03.setBackgroundResource(R.drawable.examtxt_btn_right);
            }
            else{
              answer_fragment_03.setBackgroundResource(R.drawable.examtxt_btn_wrong);
              questionR_fragment_tv.setVisibility(View.VISIBLE);
            }
            answer_fragment_02.setEnabled(false);
            answer_fragment_01.setEnabled(false);
            answer_fragment_04.setEnabled(false);
            break;
          case R.id.answer_fragment_04:
            //countdowntimer.cancel();
            if (right_answer.equalsIgnoreCase("D")){
              answer_fragment_04.setBackgroundResource(R.drawable.examtxt_btn_right);
            }
            else{
              answer_fragment_04.setBackgroundResource(R.drawable.examtxt_btn_wrong);
              questionR_fragment_tv.setVisibility(View.VISIBLE);
            }
            answer_fragment_02.setEnabled(false);
            answer_fragment_03.setEnabled(false);
            answer_fragment_01.setEnabled(false);
            break;
        }


      }
    });
  }




  /**
   * Rewrite 'CountDownTimer' method.
   *
   * @param
   *      // 倒计时总数，单位为毫秒。
   * @param
   *      // 每隔多久调用onTick一次
   * @author DaiZhenWei
   *
   */
    protected class MyCountdownTimer extends CountDownTimer {

      public MyCountdownTimer(long millisInFuture, long countDownInterval) {
        super(millisInFuture, countDownInterval);
      }
      @Override
      public void onTick(long millisUntilFinished) {
        count_fragment_down.setText("倒计时: " + millisUntilFinished / 1000);
      }
      @Override
      public void onFinish() {
        //count_fragment_down.setText("Turning");
        FightActivity.getNext(null);
      }
    }

  //fragment的懒加载 重写
  @Override
  protected void onVisible() {
    //可见的
    if(!isPrepared || !isVisible) {
      //判断isPrepared和isVisible只要有一个不为true就不往下执行
      Log.i("isPrepared",isPrepared+"____________"+isVisible);
      return;
    }
    /**
     * 倒计时
     */
    countdowntimer.start();//开始倒计时
    Log.i("isPrepared",this.i+"_______4");
  }
  @Override
  protected void onInvisible() {
    //不可见的
    if(!isPrepared || isVisible) {
      return;
    }
    Log.i("isPrepared","____________我取消了"+this.i);
    countdowntimer.cancel();//将倒计时取消

  }
/*
   //主页面
  public void loadUI(Class c){
    //启动之后跳著页面
//    Intent intent=new Intent(SplashActivity.this,MainActivity.class);
    Intent intent=new Intent(FragmentActivity.this.getContext(),c);
//    SplashActivity.this.startActivity(intent);
//    SplashActivity.this.finish();//Toast.LENGTH_LONG
  }
*/

}