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using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Web;
using System.Xml.Serialization;
namespace Hh.Mes.Common.DataTableTo
{
/// <summary>
/// DataTableHelp 的摘要说明
/// </summary>
public static class DataTableHelp
{
/// <summary>
/// 获取某一列的所有值 (字符串拼接手动 string.Join(",", x))
/// </summary>
/// <typeparam name="T">列数据类型</typeparam>
/// <param name="dtSource">数据表</param>
/// <param name="filedName">列名</param>
/// <returns></returns>
public static List<T> GetColumnValues<T>(this DataTable dtSource, string filedName)
{
return (from r in dtSource.AsEnumerable() select r.Field<T>(filedName)).ToList();
}
/// <summary>
/// 去重复数据方法
/// </summary>
public static DataTable Distinct(this DataTable dtSource, params string[] filedNames)
{
return dtSource.DefaultView.ToTable(true, filedNames);
}
/// <summary>
/// dt判断是否为null 或者 行数是否为0,true是为空，false存在数据
/// </summary>
public static bool IsEmpty(this DataTable dt)
{
return dt == null || dt.Rows.Count <= 0;
}
/// <summary>
/// string 空返回0，
/// </summary>
public static string IsEmpty(this object val, string retVal = "")
{
if (val == null) return "";
var temp = val.ToString();
return string.IsNullOrEmpty(temp) ? retVal : temp;
}
}
}
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