Question

这将返回strings：

的列表

var filesizes = from fd in files
                from tag in fd.Tags
                where tag.Id == ID.FILESIZE
                select tag.Value;

以下内容不起作用，但在查询过程中是否可以采用类似方法将string转换为int？

var filesizes = from fd in files
                from tag in fd.Tags
                where tag.Id == ID.FILESIZE
                select new { int.Parse(tag.Value) };

或者我应该使用ConvertAll as suggested here？

Answer 1

你可以这样做：

var filesizes = from fd in files
                from tag in fd.Tags
                where tag.Id == ID.FILESIZE
                select new { FileSize = int.Parse(tag.Value) };

或

var filesizes = from fd in files
                from tag in fd.Tags
                where tag.Id == ID.FILESIZE
                select int.Parse(tag.Value);

Answer 2

您可以将select int.Parse(tag)放在最后而不是select tag.Value：

var filesizes = from fd in files
                from tag in fd.Tags
                where tag.Id == ID.FILESIZE
                select int.Parse(tag.Value);

Answer 3

为什么需要用新的{...}包装整数？这很简单：

var filesizes = from fd in files
                from tag in fd.Tags
                where tag.Id == ID.FILESIZE
                select int.Parse(tag.Value);

LINQ：如何在select期间转换查询结果？

3 个答案: