为什么这个简单的代码在手机上运行太慢? [英] Why this simple code running too slowly on mobile phone?

问题描述

package MyGame;

import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.lcdui.game.Sprite;
import javax.microedition.lcdui.*;
///////

public class clsCanvas extends GameCanvas implements Runnable {

    private boolean isRunning = true;
    private Graphics g;
    private midMain fParent;

    ////////
    public Sprite cursor;
    public GameDesign gameDesign;
    ////
    public clsCanvas(midMain m) {
        super(true);
        fParent = m;
    }

        public void start(){
        Thread runner = new Thread(this);
        runner.start();
    }


    public void run() {
        this.gameDesign = new GameDesign();
        try{
        this.cursor = this.gameDesign.getCurs();
        this.cursor.defineReferencePixel(cursor.getWidth(), cursor.getHeight());
        }
        catch(Exception x){}
        int iKey = 0;
        g = getGraphics();
        g.setColor(200);
        g.fillRect(0, 0, 50, 50);
        cursor.paint(g);
        while (isRunning) {
            iKey = getKeyStates();

            if ((iKey & GameCanvas.FIRE_PRESSED) != 0) {
                isRunning = false;
            }

            if ((iKey & GameCanvas.RIGHT_PRESSED) != 0) {
        g.setColor(200);
        g.fillRect(0, 0, getWidth(), getHeight());
                cursor.setPosition(cursor.getX()+5, cursor.getY());
                cursor.paint(g);
            }
            if ((iKey & GameCanvas.LEFT_PRESSED) != 0) {
        g.setColor(200);
        g.fillRect(0, 0, getWidth(), getHeight());
                cursor.setPosition(cursor.getX()-5, cursor.getY());
                cursor.paint(g);
            }
            if ((iKey & GameCanvas.DOWN_PRESSED) != 0) {
        g.setColor(200);
        g.fillRect(0, 0, getWidth(), getHeight());
                cursor.setPosition(cursor.getX(), cursor.getY()+5);
                cursor.paint(g);
            }
            if ((iKey & GameCanvas.UP_PRESSED) != 0) {
        g.setColor(200);
        g.fillRect(0, 0, getWidth(), getHeight());
                cursor.setPosition(cursor.getX(), cursor.getY()-5);
                cursor.paint(g);
            }
            flushGraphics();
            try {
                Thread.sleep(10);
            } catch (Exception ex) {
            }
        }
        g = null;
       fParent.destroyApp(false);
       fParent = null;
    }

}

移动光标我正在等待〜每1步250ms.哪里有问题?
我尝试使用Thread.sleep(50)，30和10-都一样:(
(全屏填充不会影响速度)
请帮忙.


我将IF替换为所有其他区别.

Moving cursor I''m waiting ~ 250ms per 1 step. Where is a problem?
I tried with Thread.sleep(50), 30 and 10 - all the same:(
(Filling full screen not affect on speed)
Please, help.


I replace IFs with this and any difference.

     while ((iKey & GameCanvas.RIGHT_PRESSED) != 0) {
                g.setColor(200);
                g.fillRect(0, 0, width, height);
                cursor.setPosition(cursor.getX()+5, cursor.getY());
                cursor.paint(g);
                flushGraphics();
                try{
                Thread.sleep(10);}
                catch(Exception x){}
            iKey = getKeyStates();
}

而且，如果我快速按RIGHT，光标移动的速度将比按住RIGHT键的速度快.

And if I quickly pressing RIGHT, cursor moving faster than I press and hold RIGHT key.

推荐答案

您的代码是否依赖于异常?

为什么Thread.Sleep会抛出异常?

我建议您对代码的每个部分进行一些分析，以找出每个部分有多长时间.

循环中的Sleep(10)应该足够.

Is you code relying on an exception?

Why would Thread.Sleep ever throw an exception?

I suggest you do some analysis on each section of your code to findout how long it is in each section.

Sleep(10) in a loop should be enough.

我将重构代码:

I would refactor the code:

int height = getHeight();
int width  = getWidth();
while (isRunning) 
{
    iKey = getKeyStates();
    isRunning = ((iKey & GameCanvas.FIRE_PRESSED) != 0);
    if (isRunning)
    {
        int cursorX = cursor.GetX();
        int cursorY = cursor.GetY();
        bool refresh = false;
        if ((iKey & GameCanvas.RIGHT_PRESSED) != 0) 
        {
            refresh = true;
            cursorX += 5;
        }
        if ((iKey & GameCanvas.LEFT_PRESSED) != 0) 
        {
            refresh = true;
            cursorX -= 5;
        }
        if ((iKey & GameCanvas.DOWN_PRESSED) != 0) 
        {
            refresh = true;
            cursorY += 5;
        }
        if ((iKey & GameCanvas.UP_PRESSED) != 0) 
        {
            refresh = true;
            cursorY -= 5;
        }
	if (refresh)
        {
            g.setColor(200);
            g.fillRect(0, 0, width, height);
            cursor.setPosition(cursorX, cursorY);
            cursor.paint(g);
            flushGraphics();            
        }
    } 
    Thread.sleep(10);
}

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