Question

我不明白这个引用另一种类型'System.Collections.Generic.List`1 [CES.Model.SearchResult]'以及如何解决这个问题。

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

也许这应该有效：

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，此代码假设“results”变量属于List<SearchResult>种类。序列化程序必须匹配它将序列化的对象类型。

无法转换'System.Collections.Generic.List`1类型的对象

1 个答案: