java - 非静态变量pRefix不能从静态上下文中引用

Question

我正在尝试使用setFavoritePicture (Picture pRef)方法设置图片。
该方法应该设置一个在主方法中要调用的收藏图片，但是我一直收到表示nonstatic variable pRef cannot be referenced from a static context的编译器错误。我对Java还是比较陌生，因此非常感谢您能提供的任何帮助

public class House
{
 String owner;
 Picture pRef;
 Picture [] picArray;
 Picture favPic;

 public void showArtCollection ()
  {

   ArtWall aWall = new ArtWall(600,600);
   aWall.copyPictureIntoWhere(favPic,250,100);
   aWall.copyPictureIntoWhere(picArray[0],51,330);
   aWall.copyPictureIntoWhere(picArray[1],151,330);
   aWall.copyPictureIntoWhere(picArray[2],351,280);
   aWall.show();

  }



 public House (String param)
 {

  this.owner = param;
  this.picArray = new Picture [3];
  this.favPic = new Picture (FileChooser.pickAFile ());
  this.picArray [0] = new Picture (FileChooser.pickAFile ());
  this.picArray [1] = new Picture (FileChooser.pickAFile ());
  this.picArray [2] = new Picture (FileChooser.pickAFile ());




 }

public void setFavoritePicture (Picture pRef)
{
 pRef = favPic;
}

public void setOneOtherPicture (int which,Picture pRef)
{

}


public void swapGivenOtherWithFavorite (int which)
 {
  Picture tempSaver;
  tempSaver = pRef;
  pRef = picArray [which];
  picArray [which] = tempSaver;
 }


public void addPicture (Picture pictureAdded)
{
 pRef = pictureAdded;


}

public void showPicture ()
{

 picArray [0].explore ();
 picArray [1].explore ();
 picArray [2].explore ();
 favPic.explore ();


}


public static void main (String [] args)
 {
  House PhDsHouse = new House ("Mad PH.D.");
  PhDsHouse.setFavoritePicture (pRef);
  PhDsHouse.swapGivenOtherWithFavorite (2);
  PhDsHouse.showArtCollection ();


 }

}

Answer 1

我看到的错误如下:
PhDsHouse.setFavoritePicture (pRef);在pRef中定义了main的位置？因此，您在该语句处出错。

我猜，您想创建新的Picture对象，然后使用PhDsHouse将其分配给setFavoritePicture。这是真的？如果是，则需要在Picture pRef = new Picture();之前执行类似setFavoritePicture的操作……那么您应该很好。

另外，以下功能对我来说非常可疑

public void setFavoritePicture (Picture pRef)
{
 pRef = favPic;
}

应该是

 public void setFavoritePicture (Picture  favPic)
    {
     pRef = favPic;
    }

因为，我看不到在您的代码中 favPic的定义/初始化位置...。否则，当您访问 NULL pointer exceptions时，您将得到 pRef，因为 favPic是 NULL，它将被分配给 pRef。