java - 如何在导致运行时的 libgdx 中编写计时器

Question

我最近用这个 QuizDialog 界面创建了一个 libgdx 游戏并且我添加了 CountDownTimer，这是我从这里的不同教程中遵循的，但是当我执行游戏时，它告诉

Exception in thread "LWJGL Application" java.lang.RuntimeException: Stub!
at android.os.CountDownTimer.<init>(CountDownTimer.java:4)
at com.boontaran.games.SICT.LevelQuizDialog$2$1.<init>(LevelQuizDialog.java:184)
at com.boontaran.games.SICT.LevelQuizDialog$2.clicked(LevelQuizDialog.java:184)
at com.badlogic.gdx.scenes.scene2d.utils.ClickListener.touchUp(ClickListener.java:89)
at com.badlogic.gdx.scenes.scene2d.InputListener.handle(InputListener.java:57)
at com.badlogic.gdx.scenes.scene2d.Stage.touchUp(Stage.java:346)
at com.boontaran.games.StageGame.touchUp(StageGame.java:300)
at com.badlogic.gdx.backends.lwjgl.LwjglInput.processEvents(LwjglInput.java:325)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:199)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:114)

到目前为止，这是我的代码，

package com.boontaran.games.SICT;
import java.util.Random;
import java.util.Timer;
import java.util.TimerTask;
import java.util.logging.Handler;
import android.os.CountDownTimer;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.g2d.NinePatch;
import com.badlogic.gdx.scenes.scene2d.Group;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.ui.Image;
import com.badlogic.gdx.scenes.scene2d.ui.ImageButton;
import com.badlogic.gdx.scenes.scene2d.ui.Label;
import com.badlogic.gdx.scenes.scene2d.ui.Label.LabelStyle;
import com.badlogic.gdx.scenes.scene2d.utils.ClickListener;
import com.badlogic.gdx.scenes.scene2d.utils.TextureRegionDrawable;
import com.boontaran.MessageEvent;
public class LevelQuizDialog extends Group {
public static final int ON_CLOSE = 1;
public static final int ON_OPEN = 2;
public static final int LevelCompleted2 = 1;
public static final int LevelFailed2 = 2;

//private Timer timer;





    public LevelQuizDialog( int score) {

            // final int score2 = score;

    NinePatch patch = new NinePatch(SICT.atlas.findRegion("dialog_bg"),60,60,60,60);
    Image bg = new Image(patch);
    bg.setSize(980, 670);
    setSize(bg.getWidth() , bg.getHeight());
    addActor(bg);


    final Image title = new Image(SICT.atlas.findRegion("quiz"));
    addActor(title);
    title.setX((getWidth() - title.getWidth())/2);
    title.setY(getHeight() - title.getHeight() - 100);

    final Image title2 = new Image(SICT.atlas.findRegion("level_completed"));
    //addActor(title2);
    title2.setX((getWidth() - title2.getWidth())/2);
    title2.setY(getHeight() - title2.getHeight() - 100);

    final Image title3 = new Image(SICT.atlas.findRegion("level_failed"));
//  addActor(title3);
    title3.setX((getWidth() - title3.getWidth())/2);
    title3.setY(getHeight() - title3.getHeight() - 100);

    Image image2 = new Image(SICT.atlas.findRegion("border"));
    image2.setSize(300,120);
    addActor(image2);
    image2.setPosition(390,300);
    //score label
    LabelStyle style = new LabelStyle();
    style.font = SICT.font1;
    style.fontColor = new Color(0x624601ff);


    Label label = new Label("Score :", style);
    addActor(label);
    label.setPosition(590, 600);
    LabelStyle style2 = new LabelStyle();
    style2.font = SICT.font2;
    style2.fontColor = new Color(0x624601ff);

    //the score 
    Label scoreLabel = new Label(String.valueOf(score) , style2);
    addActor(scoreLabel);
    scoreLabel.setPosition(800, 600);


    //Label array1 = new Label("", array1); and the checking

    Random random = new Random();
    int array = random.nextInt(10) + 1;
    int array2 = random.nextInt(10) +1;
    final int answer = random.nextInt(20) +5;
    final int checker = array + array2;



    Label StringArray = new Label(String.valueOf(array), style2);
    addActor(StringArray);
    StringArray.setPosition(417,325);

    Label StringArray2 = new Label(String.valueOf(array2), style2);
    addActor(StringArray2);
    StringArray2.setPosition(520, 325);

    Label StringArray3 = new Label(String.valueOf(answer), style2);
    addActor(StringArray3);
    StringArray3.setPosition(620, 325);

    //timer
     //setPosition(20, 600);



    final ImageButton CheckBtn = new ImageButton(
            new TextureRegionDrawable(SICT.atlas.findRegion("check1")), 
            new TextureRegionDrawable(SICT.atlas.findRegion("check2")));

    addActor(CheckBtn);
    //CheckBtn.setSize(120, 120);
    CheckBtn.setX(400);
    CheckBtn.setY(70);

    final ImageButton WrongBtn = new ImageButton(
            new TextureRegionDrawable(SICT.atlas.findRegion("wrong1")), 
            new TextureRegionDrawable(SICT.atlas.findRegion("wrong2")));

    addActor(WrongBtn);
    //WrongBtn.setSize(120, 120);
    WrongBtn.setX(550);
    WrongBtn.setY(70);




    CheckBtn.addListener(new ClickListener(){


        @Override
        public void clicked(InputEvent event, float x, float y) {
            WrongBtn.clearListeners();
            if(checker == answer  )
            {
                removeActor(title);
                addActor(title2);
            }

             if(checker != answer)
            {
                 removeActor(title);
                addActor(title3);
            }




        }
    });

    //fire event on button click
    WrongBtn.addListener(new ClickListener(){
        @Override
        public void clicked(InputEvent event, float x, float y) {
            CheckBtn.clearListeners();
            if(checker != answer  )
            {
                removeActor(title);
                addActor(title2);

            }

             if(checker == answer)
            {
                 removeActor(title);
                addActor(title3);
            }

             new CountDownTimer(4000, 4000) {
                    public void onTick(long millisUntilFinished) {

                    }

                    public void onFinish() {
                      fire(new MessageEvent(ON_CLOSE));
                    }
                }.start();

        }           

    });

}

Answer 1

您不需要任何花哨的东西。您可以从 LibGDX 中的任何位置访问帧时间，它称为增量或 Gdx.graphics.getRawDeltaTime() 因为 Gdx.graphics.getDeltaTime() 提供了平滑版本。因此，您需要做的就是拥有一个按此增量递增的计数器和一个固定值(例如 10 秒)。

既然你可能想倒数，我们应该减少计数器:

float time, counter = 10f;

public void update(float delta)
{
  counter -= Gdx.graphics.getRawDeltaTime();
  //if you have delta passed as a overload you can do
  counter -= delta; //This is smoothed but should not matter for a quiz game

  if (counter <= 3)
  {
    //Play annoying sound to make you stress even more
  }

  if (counter <= 0)
  {
    //Time is up!

    //You can just reset the counter by setting it equal to time again.
    //But there will almost always be left over (counter will be less then 0)
    //So if this is important (probably not for a quiz game)
    counter = time + -counter; //Add the time this round took too long.
  }
}

这就是它的全部。如果您想以秒为单位绘制时间，您应该将计数器四舍五入。