Question

public PImage[] images;
public static File[] wallTiles = loadFolder("data/tiles/walls");
public static File[] floorTiles = loadFolder("data/tiles/floors");
public static int totalFiles = wallTiles.length+floorTiles.length;

private static File[] loadFolder(String string)
{
    File files = new File(string);

    File[] pngFiles = files.listFiles(new FilenameFilter()
    {
        public boolean accept(File directory, String fileName)
        {
            return fileName.endsWith(".png");
        };
    });
    return pngFiles;
}

第4行（其中分配了totalFiles）始终失败，因为wallTiles为null。我想在这个类（称为Art）中返回totalFiles，这样我就可以为我正在进行的游戏随机选择墙或地板纹理。谢谢收听。

Answer 1

来自API http://docs.oracle.com/javase/6/docs/api/java/io/File.html#listFiles()

...如果此抽象路径名不表示目录，则返回null ...

因此，检查目录是否存在以及是否有文件。

private static File[] loadFolder(String string)
{
    File files = new File(string);
    if(!files.exists() || !files.isDirectory()){
        System.out.println("Directory: "+string+" does not exists");       
        return new File[0];
    }

    File[] pngFiles = files.listFiles(new FilenameFilter()
    {
        public boolean accept(File directory, String fileName)
        {
            return fileName.endsWith(".png");
        };
    });
    return pngFiles;
}

Answer 2

尝试使用目录的绝对路径，而不是相对

public static File [] wallTiles = loadFolder（“data / tiles / walls”）;

- ＆GT;

public static File [] wallTiles = loadFolder（“/ whatever_path / data / tiles / walls”）;

获取静态文件数组的长度？永远回来无效

2 个答案: