从动态数据表中获取前10或20行 [英] take top 10 or 20 rows from dynamic datatable

问题描述

我在Datable中说有100条记录

I have 100 records in my Datable says to be in

DataTable dt=new DataTable();

dt 的记录中有 100 条记录，列名称为 sub_id(包含int数据类型)和 subheadername(包含nvarchar(150)))，我希望此 dt 的前 20条记录按升序顺序

dt have 100 of records say column name as sub_id(contain int datatype) and subheadername(contain nvarchar(150)) , I want top 20 records from this dt in ascending order

我将代码放置为

//dtlcategories.DataSource = dt.AsEnumerable().OrderBy(x => x["subheadername"]).Take(20).ToList();
dtlcategories.DataSource = dt.Rows.Cast<DataRow>().OrderBy(x => x["subheadername"]).Take(20).ToList();
dtlcategories.DataBind();

此处dtlcategories是数据列表"，但在运行时出现错误，因为"System.Data.DataRow"不包含名称为"subheadername"的属性.

Here dtlcategories is Datalist but on running error is coming as 'System.Data.DataRow' does not contain a property with the name 'subheadername'.

已解决答案

dtlcategories.DataSource = dt.Rows.Cast<DataRow>().OrderBy(x => x["subheadername"]).Take(20).copytodatatable();
dtlcategories.DataBind();

推荐答案

使用LINQ，有两种不同的方法可以做到这一点.这些都将返回相同的结果.

There's a couple different ways you can do this using LINQ. These will both return the same results.

dt.AsEnumerable().OrderBy(x => x["subheadername"]).Take(20);

dt.Rows.Cast<DataRow>().OrderBy(x => x["subheadername"]).Take(20);

如果要将结果用作另一个控件的数据源，则可能需要在 .Take(x)之后调用 .ToList().

If you're going to use the result as the source of data for another control, you may need to call .ToList() after .Take(x).

我根据您的修改更改了列名.如果要改为按ID排序(未指定)，只需将"subheadername"替换为"sub_id".

I changed the column name based on your edit. If you want to sort by id instead (you didn't specify), just replace "subheadername" with "sub_id".

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