如何在Processing中获取草图的路径？ （dataPath无法正常工作）

Question

使用Processing 3-0-1（尚未更新），我遇到了dataPath（）函数的问题。

我的代码：

final String path = dataPath("");
//...
void setup(){
  //...
  println(path);
  //...
}

这将显示在控制台中：

/ media / ubuntu / Expansion Drive / Programmation / Java / Processing / Ubuntu / processing-3.0.1 / null / data

但它应该显示（根据文档和我在其他项目中的尝试）：

/ media / ubuntu / Expansion Drive / Programmation / Java / Processing / Projets / Time_Fighter / data

所以它似乎正在返回一个路径Processing而不是我的项目的路径？ 另外，为什么会出现“空”？

问题是，你知道一种方法可以使我的草图的路径？

PS。 我的一个朋友建议使用File类，我得到了这个结果：

File file = new File("data");
//...
void setup(){
  //...
  file.getAbsolutePath();
  //...
}

返回的是：

/ media / ubuntu / Expansion Drive / Programmation / Java / Processing / Ubuntu / processing-3.0.1 / data

PPS。 我正在使用Ubuntu（Mate）......

Answer 1

您不应该使用dataPath()函数。 您应该使用sketchPath()函数。

从dataPath()的处理源 ：

/**
   * <b>This function almost certainly does not do the thing you want it to.</b>
   * The data path is handled differently on each platform, and should not be
   * considered a location to write files. It should also not be assumed that
   * this location can be read from or listed. This function is used internally
   * as a possible location for reading files. It's still "public" as a
   * holdover from earlier code.
   * <p>
   * Libraries should use createInput() to get an InputStream or createOutput()
   * to get an OutputStream. sketchPath() can be used to get a location
   * relative to the sketch. Again, <b>do not</b> use this to get relative
   * locations of files. You'll be disappointed when your app runs on different
   * platforms.
   */
  public String dataPath(String where) {
    return dataFile(where).getAbsolutePath();
  }

这里是sketchPath() ：

/**
   * Prepend the sketch folder path to the filename (or path) that is
   * passed in. External libraries should use this function to save to
   * the sketch folder.
   * <p/>
   * Note that when running as an applet inside a web browser,
   * the sketchPath will be set to null, because security restrictions
   * prevent applets from accessing that information.
   * <p/>
   * This will also cause an error if the sketch is not inited properly,
   * meaning that init() was never called on the PApplet when hosted
   * my some other main() or by other code. For proper use of init(),
   * see the examples in the main description text for PApplet.
   */
  public String sketchPath(String where) {
    if (sketchPath() == null) {
      return where;
    }
    // isAbsolute() could throw an access exception, but so will writing
    // to the local disk using the sketch path, so this is safe here.
    // for 0120, added a try/catch anyways.
    try {
      if (new File(where).isAbsolute()) return where;
    } catch (Exception e) { }

    return sketchPath() + File.separator + where;
  }