如何提取 Linq 表达式的结果
本文关键字:Linq 表达式 结果 提取 何提取 | 更新日期: 2023-09-27 18:31:18
我的结果表达式是
var result = dtFields.AsEnumerable().Join(dtCDGroup.AsEnumerable(),
fieldList=>fieldList.Field<string>("CDGroupID"),
cd=>cd.Field<string>("CDGroupID"),
(fieldList,cd) => new
{
FieldID = fieldList.Field<string>("FieldID"),
Name = cd.Field<string>("Name"),
CDCaption = fieldList.Field<string>("CDCaption"),
Priority = ((cd.Field<string>("Priority") == null) ? 99 : cd.Field<int>("Priority")),
fldIndex = fieldList.Field<string>("fldIndex")
}).OrderBy(result => result.Priority).ThenBy(result => result.fldIndex);
将上述结果强制转换为数组或列表会引发无效的强制转换异常。如何提取上述表达式的结果?
添加 .ToArray() 或 .ToList() 分别调用
尝试添加强类型类型:
public class NewModule
{
public int FieldID { get; set; }
public string Name { get; set; }
public string CDCaption { get; set; }
public int Priority { get; set; }
public int fldIndex { get; set; }
}
您可以使用如下所示ToList<NewModule>()
而不是匿名类型:
var result = dtFields.AsEnumerable().Join(dtCDGroup.AsEnumerable(),
fieldList=>fieldList.Field<string>("CDGroupID"),
cd=>cd.Field<string>("CDGroupID"),
(fieldList,cd) => new NewModule
{
FieldID = fieldList.Field<string>("FieldID"),
Name = cd.Field<string>("Name"),
CDCaption = fieldList.Field<string>("CDCaption"),
Priority = ((cd.Field<string>("Priority") == null) ? 99 : cd.Field<int>("Priority")),
fldIndex = fieldList.Field<string>("fldIndex")
}).OrderBy(result => result.Priority)
.ThenBy(result => result.fldIndex)
.ToList<NewModule>();