java - 无法在未调用 Looper.prepare android 的线程内创建处理程序

Question

我有一个问题，调用我在主题中编写的错误。我有 3 个类，其中一个是“主”类，而 Pavement 类则应根据 Level 类中的字符串在屏幕上添加路面对象。我该怎么做才能将该方法保留在 Pavement 类中并消除该错误。在这里我应用来源:开始:

package com.example.simplerpgdorid;

import java.util.ArrayList;
import java.util.Iterator;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Paint.Style;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.Window;
import android.view.WindowManager;

public class Start extends Activity implements OnTouchListener{
    Canvas c;
    OurView ov;
    Bitmap champ, grass, arrows;
    static Bitmap pave;
    Character character;
    Pavement pavement;
    float x, y;
    char direction = 'x';
    int topArrow[] = {370, 100, 430, 122};
    int bottomArrow[] = {370, 195, 430, 223};
    int leftArrow[] = {342, 130, 366, 184};
    int rightArrow[] = {434, 130, 464, 184};
    int lvlx;
    public static int gowno = 0;

    static Iterator<Locatable> itrLocatables;
    static ArrayList<Pavement> pavements = new ArrayList<Pavement>();
    static ArrayList<Locatable> locatables = new ArrayList<Locatable>();
    static ArrayList<Locatable> locatablesArray = new ArrayList<Locatable>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        Level lll = new Level();
        ov = new OurView(this);
        lvlx = 1;

        champ = BitmapFactory.decodeResource(getResources(), R.drawable.s1);
        grass = BitmapFactory.decodeResource(getResources(), R.drawable.grass);
        arrows = BitmapFactory.decodeResource(getResources(), R.drawable.arrows);
        pave = BitmapFactory.decodeResource(getResources(), R.drawable.pavement);



        character = new Character(ov, champ);
        pavement = new Pavement(3, 3, pave);
        pavement.setBitmap(pave);

        initLocatables();
        initLocatables2();

        ov.setOnTouchListener(this);
        setContentView(ov);
    }



    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        ov.pause();
    }



    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
        ov.resume();
    }



    @Override
    public boolean onTouch(View v, MotionEvent event) {
        // TODO Auto-generated method stub
        try {
            Thread.sleep(10);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        switch(event.getAction()){
            case MotionEvent.ACTION_MOVE:
                x = event.getX();
                y = event.getY();

                if(x > topArrow[0] && x < topArrow[2] && y > topArrow[1] && y < topArrow[3]){
                    direction = 'w';
                }
                else if(x > bottomArrow[0] && x < bottomArrow[2] && y > bottomArrow[1] && y < bottomArrow[3]){
                    direction = 's';
                }               
                else if(x > leftArrow[0] && x < leftArrow[2] && y > leftArrow[1] && y < leftArrow[3]){
                    direction = 'a';
                }
                else if(x > rightArrow[0] && x < rightArrow[2] && y > rightArrow[1] && y < rightArrow[3]){
                    direction = 'd';
                }else{
                    direction = 'x';
                }
                break;

            case MotionEvent.ACTION_DOWN:

                break;

            case MotionEvent.ACTION_UP:

                break;
        }

        return true;
    }


    public class OurView extends SurfaceView implements Runnable{

        Thread thread = null;
        boolean isGoing = false,    spriteLoaded = false;
        SurfaceHolder holder;

        public OurView(Context context) {
            super(context);
            // TODO Auto-generated constructor stub
            holder = getHolder();
        }

        @Override
        public void run() {
            // TODO Auto-generated method stub
            while(isGoing){
                if(!holder.getSurface().isValid()){
                    continue;
                }
                for(Locatable l : locatables)
                {
                    l.isDeInited();
                    l.isInited();
                }
                pavement.deInit(Level.lvl[lvlx]);
                pavement.init(Level.lvl[lvlx]);
                c = holder.lockCanvas();
                draw(c);
                holder.unlockCanvasAndPost(c);
            }
        }

        public void pause(){
            isGoing = false;
            while(true){
                try{
                    thread.join();
                }catch(InterruptedException e){
                    e.printStackTrace();
                }
                break;
            }
            thread = null;
        }

        public void resume(){
            isGoing = true;
            thread = new Thread(this);
            thread.start();     

        }

        public void draw(Canvas canvas){
            canvas.drawARGB(255, 100, 100, 100);
            canvas.drawBitmap(grass, 0, 0, null);


            Paint paint = new Paint();
            paint.setColor(Color.GRAY);
            paint.setStyle(Style.FILL);
            paint.setTextSize(15);
            Rect UI = new Rect();
            UI.set(320, 0, getWidth(), getHeight());
            canvas.drawRect(UI, paint);
            canvas.drawBitmap(arrows, getWidth() - arrows.getWidth() - 16, getHeight()/2 - arrows.getHeight()/2, null);




            initLocatables();
            initLocatables2();
            for (@SuppressWarnings("rawtypes")Iterator i = locatablesArray.listIterator(); i.hasNext();) 
            {
                Locatable l = (Locatable) i.next(); 
                l.draw(canvas);
            }
            locatablesArray.clear();




            pavement.draw(canvas);

            //Debug
            character.draw(canvas, direction);
            paint.setColor(Color.RED);
            canvas.drawText("x = " + x + " y = " + y + " " + gowno , 20, 20, paint);
            canvas.drawCircle(x, y, 5, paint);
        }
    }

    public void initLocatables()
    {
        locatables.add(pavement);
    }
    public void initLocatables2()
    {
        locatablesArray.addAll(pavements);
        itrLocatables = locatablesArray.listIterator();
    }

}

路面:

package com.example.simplerpgdorid;

import com.example.simplerpgdorid.Start.OurView;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.util.Log;

public class Pavement extends Activity implements Locatable{

    OurView v;
    Bitmap b = null;
    int x, y, size;
    boolean isInited = false,   isDeInited;

    public Pavement(int x, int y, Bitmap bit){
        this.x = x * 32;
        this.y = y * 32;
        this.b = bit;
    }



    public void init(String[] xlevel){
        Start.pavements.add(new Pavement(32, 32, getbitmap()));
        Start.pavements.add(new Pavement(52, 52, getbitmap()));
        Start.pavements.add(new Pavement(22 , 66, getbitmap()));
        if(!isInited){
            for(int z = 0; y < Level.lvl.length; y++){
                for(int s = 0; x < Level.lvl.length; x++){
                    if(xlevel[z].charAt(s) == 'p'){
                        Start.pavements.add(new Pavement(z, s, getbitmap()));

                    }
                    Start.gowno ++;
                }
            }
        }   
        isInited = true;
    }

    public void deInit(String[] xlevel)
    {
        if(!isDeInited)
        for(int y = 0; y < Start.pavements.size(); y++)
        {
            Start.pavements.get(y).x = -100;
            Start.pavements.get(y).y = -100;
        }
        isDeInited = true;
    }

    @Override
    public void draw(Canvas canvas) {
        // TODO Auto-generated method stub
        canvas.drawBitmap(getbitmap(), x, y, null);
    }
    @Override
    public void isInited() {
        // TODO Auto-generated method stub
        isInited = false;
    }
    @Override
    public void isDeInited() {
        // TODO Auto-generated method stub
        isDeInited = false;
    }

    @Override
    public Bitmap getbitmap() {
        // TODO Auto-generated method stub
        Bitmap bmp = null;
        bmp = b;
        return bmp;
    }

    @Override
    public void setBitmap(Bitmap bmp) {
        // TODO Auto-generated method stub
        this.b = bmp;
    }

}

和级别:

package com.example.simplerpgdorid;

public class Level {
    public static String lvl[][] = new String[2][];
    public Level(){
        lvl[0] = new String[]{
                "...p.....p",
                "...p.....p",
                "...p.....p",
                "...p.....p",
                "...p.....p",
                "...p.....p",
                "...p.....p",
                "...p.....p",
                "...p.....p",
                "...p.....p",
            };
        lvl[1] = new String[]{
                "...p.....p",
                "...p.....p",
                "...p.....p",
                "...p.....p",
                "...p.pp..p",
                "...p.....p",
                "...p.....p",
                "...p.....p",
                "...p.....p",
                "...p.....p",
            };
    }
}

Answer 1

当我的 Android 库在某些 native 引擎(如 Unity)中使用时，我遇到了这些问题。

当我不确定代码何时在需要循环器的线程上执行时，我使用了以下方法:

    if (Looper.myLooper() == null) {
        Looper.prepare();
    }