Processing 数组中处理时出现空指针异常。什么都试过了

我正在做一个2d侧滚游戏，我被卡住了。我正在为越来越多的对象编写类，玩家必须避免这些对象。但遗憾的是，我得到了一个Nullpointerexception，我不知道为什么。在我清理主代码并将其转换为类之前，整个过程都正常工作。我认为我正确初始化了数组，没有未定义的变量。在过去的几个月里，我一直在使用处理，所以我可能会监督一些事情

非常感谢你的帮助

 public class Blockfield {
    private int Blockcount;
    private PImage Blockpic;
    private Block block[];

  //Constructor
  public Blockfield (int Blockcount) {
    this.Blockcount = Blockcount; 
    //new array
    block = new Block [Blockcount];
    for ( int i=0; i < Blockcount; i++) {
      block[i] = new Block( width+Blockpic.width, random (height));
    }
  }


  //Draw method for this class
  public void draw () {
    for (int i =frameCount/100; i >0; i--) {
      image ( Blockpic, block[i].x, block[i].y);
      //moves blocks right to left
      block[i].x -=7 ;
      //spawns block when they leave the screen
      if (block[i].x < 0) {
        block[i] = new Block( width+Blockpic.width, random (height));
      }
    }
  }
}

class Block {
float x, y;

Block ( float x, float y) {
this.x= x;
this.y= y;
}
}

---

问题是，在分配

Blockpic

之前，我正在尝试访问

Blockpic.width

中的

Blockfield

构造函数。解决方案是在类的构造函数中加载映像

工作代码：

public class Blockfield {
    private int Blockcount;
    private PImage Blockpic;
    private Block block[];

  //Constructor
  public Blockfield (int Blockcount) {
    this.Blockcount = Blockcount; 
    Blockpic = loadImage("block2.png");
    //new array
    block = new Block [Blockcount];
    for ( int i=0; i < Blockcount; i++) {
      block[i] = new Block( width+Blockpic.width, random (height));
    }
  }


  //Draw method for this class
  public void draw () {
    for (int i =frameCount/100; i >0; i--) {
      image ( Blockpic, block[i].x, block[i].y);
      //moves blocks right to left
      block[i].x -=7 ;
      //spawns block when they leave the screen
      if (block[i].x < 0) {
        block[i] = new Block( width+Blockpic.width, random (height));
      }
    }
  }
}

class Block {
float x, y;

Block ( float x, float y) {
this.x= x;
this.y= y;
}
}

公共类区块字段{
私有int区块计数；
私人PImage Blockpic；
私人大厦【】；
//建造师
公共区块字段（int Blockcount）{
this.Blockcount=Blockcount；
Blockpic=loadImage（“block2.png”）；
//新阵列
块=新块[块计数]；
for（int i=0；i0；i--）{
图像（块pic，块[i].x，块[i].y）；
//从右向左移动块
块[i].x-=7；
//当它们离开屏幕时生成块
if（块[i].x<0）{
块[i]=新块（宽度+块图片宽度，随机（高度））；
}
}
}
}
类块{
浮动x，y；
块（浮动x、浮动y）{
这个.x=x；
这个。y=y；
}
}

---

谢谢大家的帮助

您使用的编程语言有名称吗？空指针发生在哪里？在分配

Blockpic

之前，您正在访问

Blockfield

构造函数中的

Blockpic.width

。您好。即时通讯使用处理2.2.1。空指针出现在块[i]=新块（宽度+块pic.width，random（高度））；这是否意味着我必须在课堂上加载图像？我已经编写了类似的代码，足以在主循环中加载图像。我尝试将Blockpic设置为公共int，但仍然出现错误。

public class Blockfield {
    private int Blockcount;
    private PImage Blockpic;
    private Block block[];

  //Constructor
  public Blockfield (int Blockcount) {
    this.Blockcount = Blockcount; 
    Blockpic = loadImage("block2.png");
    //new array
    block = new Block [Blockcount];
    for ( int i=0; i < Blockcount; i++) {
      block[i] = new Block( width+Blockpic.width, random (height));
    }
  }


  //Draw method for this class
  public void draw () {
    for (int i =frameCount/100; i >0; i--) {
      image ( Blockpic, block[i].x, block[i].y);
      //moves blocks right to left
      block[i].x -=7 ;
      //spawns block when they leave the screen
      if (block[i].x < 0) {
        block[i] = new Block( width+Blockpic.width, random (height));
      }
    }
  }
}

class Block {
float x, y;

Block ( float x, float y) {
this.x= x;
this.y= y;
}
}