c# - 无法转换类型为“System.Collections.Generic.List”的对象 1

Question

我不明白对另一种类型“System.Collections.Generic.List`1[CES.Model.SearchResult]”的引用以及如何解决此问题。

Unable to cast object of type 'System.Collections.Generic.List`1[CES.Model.SearchResult]' to type 'CES.Model.SearchResult'. 
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.InvalidCastException: Unable to cast object of type 'System.Collections.Generic.List`1[CES.Model.SearchResult]' to type 'CES.Model.SearchResult'.

Source Error: 


Line 1069:            XmlSerializer xs = new XmlSerializer(typeof(SearchResult));
Line 1070:            TextWriter textWriter = new StreamWriter(@"C:\temp\results.xml");
Line 1071:            xs.Serialize(textWriter, results);
Line 1072:            ViewState["eventList"] = textWriter.ToString();
Line 1073:            textWriter.Close();

这是 searchResult 类，它包含 SearchResultAttribute 类。

public class SearchResult
{
    private List<SearchResultAttribute> _attributes = null;
    private List<SearchResult> _linkedSearchResults = null;

    public string this[string key]
    {
        get
        {
            int resultIndex = _attributes.BinarySearch(new SearchResultAttribute(key, ""));

            if (resultIndex < 0)
                return "";
            else
                return _attributes[resultIndex].Value;
        }
        set
        {
            int resultIndex = _attributes.BinarySearch(new SearchResultAttribute(key, ""));

            if (resultIndex < 0)
                return;
            else
                _attributes[resultIndex].Value = value;
        }
    }

    public List<SearchResultAttribute> Attributes
    {
        get
        {
            return _attributes;
        }
        set
        {
            _attributes = value;
        }
    }
    public List<SearchResult> LinkedSearchResults
    {
        get
        {
            return _linkedSearchResults;
        }
        set
        {
            _linkedSearchResults = value;
        }
    }

    public SearchResult()
    {
        _attributes = new List<SearchResultAttribute>();
        _linkedSearchResults = new List<SearchResult>();
    }
}

public class SearchResultAttribute:IComparer<SearchResultAttribute>,IComparable<SearchResultAttribute>
{
    public string Key { get; set; }
    public string Value { get; set; }

    public SearchResultAttribute()
    {
        Key = System.String.Empty;
        Value = System.String.Empty;
    }

    public SearchResultAttribute(string key, string value)
    {
        Key = key;
        Value = value;
    }

    public int Compare(SearchResultAttribute x, SearchResultAttribute y)
    {
        return (x.Key.CompareTo(y.Key));
    }

    public int CompareTo(SearchResultAttribute other)
    {
        return this.Key.CompareTo(other.Key);
    }

}

感谢您的时间。

Answer 1

也许这应该工作：

XmlSerializer xs = new XmlSerializer(typeof(List<SearchResult>));

事实上，该消息让我认为 xml 包含 searchrestult 的集合，而不是单个搜索结果。

[编辑] DJ KRAZE 是对的，这段代码假设“结果”变量是 kind List<SearchResult>。序列化程序必须匹配它将序列化的对象类型。