自定义类型的 GetEnumerator 错误

Question

我有以下 Class...

class gridRecord
{
    //Constructor
    public gridRecord()
    {
        Quantity = new quantityField();
        Title = new titleField();
        Pages = new pagesField();
    }
    private quantityField quantity;
    private titleField title;
    private pagesField pages;



    internal quantityField Quantity
    {
        get { return quantity; }
        set { quantity = value; }
    }

    internal titleField Title
    {
        get { return title; }
        set { title = value; }
    }

    internal pagesField Pages
    {
        get { return pages; }
        set { pages = value; }
    }
}

我希望能够将每个字段的名称作为字符串获取，这样我以后就可以创建一个数据表而不必指定每一列。

List<gridRecord> lgr = new List<gridRecord>();
lgr = populatedList();

foreach(gridField gf in lgr[0])
    MessageBox.Show(gf.ToString());

但是我得到这个错误：

Error 1 foreach statement cannot operate on variables of type 'XML__Console.gridRecord' because 'XML__Console.gridRecord' does not contain a public definition for 'GetEnumerator'

我假设我需要继承表单和界面之类的东西，但不确定如何继承或继承哪一个。

已添加网格字段...

class gridField : Validateit
{
    public gridField()
    {
        Value = "---";
        isValid = false;
        message = "";
    }
    private string value;
    protected bool isValid;
    private string message;

    public string Value
    {
        get { return this.value; }
        set { this.value = value; }
    }
    public bool IsValid
    {
        get { return isValid; }
        set { isValid = value; }
    }
    public string Message
    {
        get { return message; }
        set { message = value; }
    }
    public override void Validate()
    {

    }
}

下面添加的quantityField其他字段大同小异

class quantityField : gridField
    {

        public void validate()
        {            
            if (isQuantityValid(Value) == false) { Value = "Invalid";}           
        }

        public static bool isQuantityValid(string quantity)
        {

            if (quantity.Length > 3)
            {
                return true;
            }
            else
            {
                return false;
            }
        }

    }

Answer 1

您正在尝试迭代集合中的一个元素。

foreach(gridField gf in lgr[0])
{
    MessageBox.Show(gf.ToString());
}

如果您的目标是检索 class 中每个属性的名称，那么请执行此操作。

PropertyInfo[] props = typeof(gridRecord).GetProperties();
foreach(PropertyInfo prop in props) 
{
    object[] attrs = prop.GetCustomAttributes(true);
    foreach(object attr in attrs) 
    {
        AuthorAttribute authAttr = attr as AuthorAttribute;
        if (authAttr != null) 
        {
            string propName = prop.Name;
            string auth = authAttr.Name;
        }
    }
}

Answer 2

据我了解，您想从 gridRecord class 中获取属性的名称（根据您的示例："Quantity"、"Title"、"Pages")?

为此，您需要使用反射：

var properties = typeof(gridRecord).GetProperties();
foreach (PropertyInfo propInfo in properties) {
    MessageBox.Show(propInfo.Name);
}

Answer 3

如果您想获取每个字段的名称，您应该使用 reflection。
PropertyInfo class 应该会有帮助

自定义类型的 GetEnumerator 错误

GetEnumerator Error with Custom Type

c#

oop

ienumerable