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<QuestionEntity  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
}
*/
}