C# CopyToDataTable不工作…生成错误
我从msdn获得了一个示例,代码是:C# CopyToDataTable不工作…生成错误,c#,linq,C#,Linq,我从msdn获得了一个示例,代码是: using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; namespace LINQTest { public partial class
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace LINQTest
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Item[] items = new Item[]
{ new Book{Id = 1, Price = 13.50, Genre = "Comedy", Author = "Gustavo Achong"},
new Book{Id = 2, Price = 8.50, Genre = "Drama", Author = "Jessie Zeng"},
new Movie{Id = 1, Price = 22.99, Genre = "Comedy", Director = "Marissa Barnes"},
new Movie{Id = 1, Price = 13.40, Genre = "Action", Director = "Emmanuel Fernandez"}};
// Load into an existing DataTable, expand the schema and
// autogenerate a new Id.
DataTable table = new DataTable();
DataColumn dc = table.Columns.Add("NewId", typeof(int));
dc.AutoIncrement = true;
table.Columns.Add("ExtraColumn", typeof(string));
var query = from i in items
where i.Price > 9.99
orderby i.Price
select new { i.Price, i.Genre };
query.CopyToDataTable(table, LoadOption.PreserveChanges);
}
}
public class Item
{
public int Id { get; set; }
public double Price { get; set; }
public string Genre { get; set; }
}
public class Book : Item
{
public string Author { get; set; }
}
public class Movie : Item
{
public string Director { get; set; }
}
}
CopyToDataTable出现错误。我遗漏了什么吗?您必须将对象强制转换为数据行 试试这个:
query.Select(el =>
{
DataRow row =
table.NewRow();
row["ExtraColumn"] = el.Genre;
return row;
}
).CopyToDataTable(table, LoadOption.PreserveChanges);
你遇到了什么类型的错误?你问了263个问题,但你仍然发布了一个只有一堵墙的代码b没有正确的格式c没有错误详细信息?我自己尝试过,因为我可以学到一些东西。但是给我们你所犯的错误会让事情变得容易很多。