LINQ To XML錯誤：select子句中的表達式類型不正確。 調用“選擇”時類型推斷失敗

Question

我正在嘗試讀取XML文件，但是type of the expression in the select clause is incorrect. Type inference failed in the call to 'Select'獲取type of the expression in the select clause is incorrect. Type inference failed in the call to 'Select' 由於以下查詢type of the expression in the select clause is incorrect. Type inference failed in the call to 'Select'錯誤type of the expression in the select clause is incorrect. Type inference failed in the call to 'Select' ：

List<Data> dogs = (from q in doc.Descendants("dog")
    where (string)q.Attribute("name") == dogName
        select new Data
        {
            name = q.Attribute("name").Value,
            breed = q.Element("breed").Value,
            sex = q.Element("sex").Value
        }.ToList<Data>);

資料類別：

public class Data
{
    public string name { get; set; }
    public string breed { get; set; }
    public string sex { get; set; }
    public List<string> dogs { get; set; }
}

Answer 1

問題在於右括號-當您打算將其放在對象初始化程序的末尾時，已將其放在ToList()調用的末尾。 另外，您實際上並沒有調用方法-您只是在指定方法組。 最后，您可以讓類型推斷為您算出type參數：

List<Data> dogs = (from q in doc.Descendants("dog")
                   where (string)q.Attribute("name") == dogName
                   select new Data
                   {
                       name = q.Attribute("name").Value,
                       breed = q.Element("breed").Value,
                       sex = q.Element("sex").Value
                   }).ToList();