小编God*_*God的帖子

我试图从AsyncTask我的搜索活动中显示一个结果.

我有一个以前的应用程序的例子,这是在一位同事的帮助下完成的(我是那里的实习生).

我根据这个应用程序的需要调整了示例,但现在我得到了NullPointerException:

03-04 03:50:23.865: E/AndroidRuntime(8224): FATAL EXCEPTION: main 
03-04 03:50:23.865: E/AndroidRuntime(8224): Process: com.cyberdog.what2watch, PID: 8224
03-04 03:50:23.865: E/AndroidRuntime(8224): java.lang.NullPointerException: Attempt to invoke interface method 'void com.cyberdog.what2watch.JsonHandling$IOnFinish.onGetData(org.json.JSONObject)' on a null object reference
03-04 03:50:23.865: E/AndroidRuntime(8224):     at com.cyberdog.what2watch.JsonHandlingTMDBAsync.onPostExecute(JsonHandling.java:321)
03-04 03:50:23.865: E/AndroidRuntime(8224):     at com.cyberdog.what2watch.JsonHandlingTMDBAsync.onPostExecute(JsonHandling.java:1)
03-04 03:50:23.865: E/AndroidRuntime(8224):     at android.os.AsyncTask.finish(AsyncTask.java:632)
03-04 03:50:23.865: E/AndroidRuntime(8224):     at android.os.AsyncTask.access$600(AsyncTask.java:177)
03-04 03:50:23.865: E/AndroidRuntime(8224):     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
03-04 03:50:23.865: E/AndroidRuntime(8224):     at android.os.Handler.dispatchMessage(Handler.java:102)
03-04 03:50:23.865: E/AndroidRuntime(8224):     at android.os.Looper.loop(Looper.java:135)
03-04 03:50:23.865: E/AndroidRuntime(8224):     at android.app.ActivityThread.main(ActivityThread.java:5274)
03-04 03:50:23.865: E/AndroidRuntime(8224):     at …

我有2 Thread秒做一些网络计算.当我运行我的应用程序并开始我的第二个后,Thread我得到一个:

Suspending all threads took: ms 警告后跟:

Background sticky concurrent mark sweep GC freed 246745(21MB) AllocSpace objects, 169(6MB) LOS objects, 33% free, 31MB/47MB, paused 1.972ms total 127.267ms 警告.

有时候我会得到那两个警告,有时我会收到很多这两个警告,直到我决定终止应用程序运行.在这一点上,它只是运行主要Thread,基本上什么都不做.这是相关代码:

MainActivity.java:

protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Getting html page through a thread
    this.getHtmlPageThread = new GetHtmlPageThread(URL_STRING);
    this.getHtmlPageThread.start();

    // The thread that will search the web for data
    this.getDataFromTheWebThread = new GetDataFromTheWebThread();

    // Search button click listener
    searchButton.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public …

我收到以下代码的错误,这是不可能的.

我检查了程序,它运行得很完美,包括那种方法.

有关无法访问的代码错误的来源是什么的任何建议？

public static string GetStringNumber(Card a)
{
    switch (a.number)
    {
        case Number.Ace:
            return "Ace";
            break;
        case Number.Two:
            return "Two";
            break;
        case Number.Three:
            return "Three";
            break;
        case Number.Four:
            return "Four";
            break;
        case Number.Five:
            return "Five";
            break;
        case Number.Six:
            return "Six";
            break;
        case Number.Seven:
            return "Seven";
            break;
        case Number.Eight:
            return "Eight";
            break;
        case Number.Ten:
            return "Ten";
            break;
        case Number.Jack:
            return "Jack";
            break;
        case Number.Queen:
            return "Queen";
            break;
        case Number.King:
            return "King";
        default:
            return "Somthing got wrong";
            break;
    }
}

我要添加到ArrayList的Thread协调的,其代表具有(X,Y)球和move()方法的新球Thread每5秒.所以我的JPanel工具Runnable和那里我添加了ArrayList一个新的球Thread.在paintComponent()方法中,我使用foreach循环迭代ArrayList球Thread的并开始Thread移动它们并呼叫repaint().问题是ii根本看不到任何绘图(只有玩家绘图).

MyPanel.java:

public class MyPanel extends JPanel implements KeyListener,Runnable
{
    private static final long serialVersionUID = 1L;

    private static final Color BACKGROUND_COLOR = Color.WHITE; 
    private static final Color NPC_BALLS_COLOR = Color.RED;

    // The player is an oval
    private int playerRadius = 20;
    private int playerX;
    private int playerY;

    // True - …

我有这个代码:

num = range(1,33)
num[0]=1
num[1]=2
for i in range(2,32):
    num[i]=num[i-1]+num[i-2]


total=0
for i in range(0,32):
    print num[i]
    if num[i]%2==0:
    total=total+num[i]
    else:
    num[i]=num[i+1]

我想找到num数组中偶数的总和.任何人都可以建议我在这里做错了吗？

我正在尝试制作一个演示飞船射击游戏.每当我按空格键时,我Image在paintComponent(Graphics g)方法中绘制一个新的抛射物()并调用moveProjectile()方法.问题是该moveProjectile()方法似乎已关闭.

MyJPanel.java

import java.awt.Cursor;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.image.BufferedImage;
import java.util.ArrayList;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;

public class MyJPanel extends JPanel implements ActionListener
{
    private static final long serialVersionUID = 1L;

    private Timer timer;
    private Image backgroundImage;
    private Image player;
    private int playerX, playerY;
    private int projectileX,projectileY;
    private Image projectileImage;
    private …