为什么在C＃到Mono中将此变量列为未分配的局部变量

Question

我无法确定为什么这里的代码不能使用Mono 2.10.6在Win32上的MonoDevelop 2.8.2中编译。 Monodevelop表明found_image_paths是一个未分配的局部变量？

我在这里遗漏了什么吗？我是C＃

的新手

    string path = this.DirectoryChooser.CurrentFolder;

    Console.WriteLine ("Selected Path: " + path);

    //Iterate over all DAE files in this folder
    string[] model_paths =  Directory.GetFiles(path,"*.dae");
    HashSet<string> found_image_paths;

    foreach (string dae_path in model_paths)
    {

        XmlDocument xmlDoc= new XmlDocument(); //* create an xml document object.

        xmlDoc.Load(dae_path); //* load the XML document from the specified file.

        //* Get elements.
        XmlNodeList library_images = xmlDoc.GetElementsByTagName("library_images");

        System.Console.WriteLine(dae_path);
        foreach (XmlNode image_node in library_images[0].ChildNodes) {
            string image_path = image_node.FirstChild.InnerText;
            found_image_paths.Add(image_path);
            Console.WriteLine(image_path);
        }



    }
    //The next line returns the error "Use of unassigned local variable 'found_image_paths'
    foreach (var item in found_image_paths) {

Answer 1

因为它未分配;您需要实例化一个哈希集并将其分配给您的变量，或者至少为其分配null。

Answer 2

这是对的。你需要初始化它。