Question

我想遍历一个类并列出它的变量。在SO上已经多次询问了这个问题，我已经尝试了所有答案。

由于某种原因，我无法获得解决方案。当我运行下面的代码（该代码应该两次遍历该类，以尝试不同的方式）时，答案只是读取“ Test1”，这意味着它没有遍历该类。

有人知道为什么循环没有运行吗？

public partial class Tables : Form
{
  private void dataGridViewNodes_CellValueChanged(object sender, DataGridViewCellEventArgs e)
    {
        Debug.WriteLine("test1");
        //Simple Test
        foreach (PropertyInfo prop in typeof(NodeHeaders).GetProperties())
        {
            Debug.WriteLine("test2");
            Debug.WriteLine(prop.Name);
        }

        //the above should have looped through the class so let's try again
        var nodeHeaders = new NodeHeaders();
        Type t = nodeHeaders.GetType();
        string fieldName;
        object propertyValue;

        // Use each property of the object passed in
        foreach (PropertyInfo pi in t.GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic))
        {
            // Get the name of the property
            fieldName = pi.Name;

            // Get the value of the property
            propertyValue = pi.GetValue(nodeHeaders, null);
            Debug.WriteLine("test3");
            Debug.WriteLine(fieldName + ": " + (propertyValue == null ? "null" : propertyValue.ToString()));
        }

    }
}

public class NodeHeaders
{
    public static string node_name = "Conduit Name";
    public static string x = "Easting (m)";
    public static string y = "Northing (m)";
    public static string z_cover = "Cover Level (m)";

}

编辑：

基于Nico Schertler的评论表，他解释说我需要遍历字段而不是属性，我还尝试了以下相同的结果。

Type type = typeof(NodeHeaders);
foreach (var p in type.GetFields(System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic))
{
    var v = p.GetValue(null); // static classes cannot be instanced, so use null...
    Debug.WriteLine(v.ToString());
}

Answer 1

由于您要访问的内容是公共静态字段，因此应使用 t.GetFields(BindingFlags.Static | BindingFlags.Public)

foreach (var field in typeof(NodeHeaders).GetFields(BindingFlags.Static | BindingFlags.Public))
{        
    // Get the name of the property
    string fieldName = field.Name;
    // Get the value of the property
    object propertyValue = field.GetValue(null);
    Console.WriteLine("test3");
    Console.WriteLine(fieldName + ": " + (propertyValue == null ? "null" : propertyValue.ToString()));
}

这将正确访问字段值：

Answer 2

这对您有用吗？

public class NodeHeaders
{
    public static string node_name = "Conduit Name";
    public static string x = "Easting (m)";
    public static string y = "Northing (m)";
    public static string z_cover = "Cover Level (m)";

}

class Program
{




    static void Main(string[] args)
    {

        DataGridViewNodes_CellValueChanged();



    }

private static void DataGridViewNodes_CellValueChanged()
{
        try
        {


    foreach (FieldInfo prop in typeof(NodeHeaders).GetFields())
    {

        object item = prop.GetValue(null);
                Console.WriteLine($"{prop.Name} = {item.ToString()}");
    }

        }
        catch (Exception ex)
        {

            throw;
        }

        Console.ReadKey();

}

}

使用反射遍历类变量

2 个答案: