/// <summary>
/// 转化为DataTable
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="varlist"></param>
/// <param name="fn"></param>
/// <returns></returns>
/// 创建时间：2018-5-29
public static DataTable ToDataTable <T>(this IEnumerable <T> varlist, CreateRowDelegate <T> fn)
{
DataTable dtReturn = new DataTable();
// column names
PropertyInfo[] oProps = null;
// Could add a check to verify that there is an element 0
foreach (T rec in varlist)
{
// Use reflection to get property names, to create table, Only first time, others will follow
if (oProps == null)
{
oProps = ((Type)rec.GetType()).GetProperties();
foreach (PropertyInfo pi in oProps)
{
Type colType = pi.PropertyType; if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition() == typeof(Nullable <>)))
{
colType = colType.GetGenericArguments()[0];
}
dtReturn.Columns.Add(new DataColumn(pi.Name, colType));
}
}
DataRow dr = dtReturn.NewRow(); foreach (PropertyInfo pi in oProps)
{
dr[pi.Name] = pi.GetValue(rec, null) == null ? DBNull.Value : pi.GetValue(rec, null);
}
dtReturn.Rows.Add(dr);
}
return(dtReturn);
}
/// <summary>
/// T
/// </summary>
/// <param name="varlist">the IEnumerable list</param>
/// <param name="fn"> function to create new object such as rec => new object[] {query}</param>
/// <typeparam name="T"></typeparam>
/// <returns>DataTable Object</returns>
public static DataTable ToAdoTable <T>(this IEnumerable <T> varlist, CreateRowDelegate <T> fn)
{
var dtReturn = new DataTable();
// Could add a check to verify that there is an element 0
var enumerable = varlist as T[] ?? varlist.ToArray();
T topRec = enumerable.ElementAt(0);
// Use reflection to get property names, to create table
// column names
var oProps = topRec.GetType().GetProperties();
foreach (var pi in oProps)
{
var colType = pi.PropertyType; if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition() == typeof(Nullable <>)))
{
colType = colType.GetGenericArguments()[0];
}
dtReturn.Columns.Add(new DataColumn(pi.Name, colType));
}
foreach (var rec in enumerable)
{
var dr = dtReturn.NewRow(); foreach (PropertyInfo pi in oProps)
{
dr[pi.Name] = pi.GetValue(rec, null) ?? DBNull.Value;
}
dtReturn.Rows.Add(dr);
}
return(dtReturn);
}
public static DataTable ToDataTable <T>(this IEnumerable <T> varlist, CreateRowDelegate <T> fn, string[] fields = null)
{
//存表的列名
DataTable dtReturn = new DataTable();
// 访问属性元素
PropertyInfo[] oProps = null;
// 判断属性元素大于0就遍历
foreach (T rec in varlist)
{
// 用反射来获取属性名，创建表，只执行第一次
if (oProps == null)
{
//得到公有属性
oProps = ((Type)rec.GetType()).GetProperties();
//遍历属性中的数据
foreach (PropertyInfo pi in oProps)
{
if (fields != null && string.IsNullOrWhiteSpace(fields.FirstOrDefault(s => s.ToLower().Equals(pi.Name.ToLower()))))
{
continue;
}
//获取属性的名称与类型
Type colType = pi.PropertyType;
if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition() == typeof(Nullable <>)))
{
colType = colType.GetGenericArguments()[0];
}
dtReturn.Columns.Add(new DataColumn(pi.Name, colType));
}
}
//将数据填充到行中
DataRow dr = dtReturn.NewRow();
foreach (PropertyInfo pi in oProps)
{
if (fields != null && string.IsNullOrWhiteSpace(fields.FirstOrDefault(s => s.ToLower().Equals(pi.Name.ToLower()))))
{
continue;
}
dr[pi.Name] = pi.GetValue(rec, null) == null ? DBNull.Value : pi.GetValue(rec, null);
}
dtReturn.Rows.Add(dr);
}
return(dtReturn);
}
/// <summary>
/// Convert list to Data Table
/// </summary>
/// <typeparam name="T">Target Class</typeparam>
/// <param name="iEnumerable">list you want to convert it to Data Table</param>
/// <param name="fn">Delegate Function to Create Row</param>
/// <returns>Data Table That Represent List data</returns>
internal static DataTable ToDataTable <T>(IEnumerable <T> iEnumerable, CreateRowDelegate <T> fn)
{
if (fn is null)
{
throw new ArgumentNullException(nameof(fn));
}
using var toReturn = new DataTable();
// Could add a check to verify that there is an element 0
IEnumerable <T> enumerable = iEnumerable.ToList();
T topRec = enumerable.ElementAtOrDefault(0);
if (topRec == null)
{
return(toReturn);
}
// Use reflection to get property names, to create table
// column names
PropertyInfo[] oProps = topRec.GetType().GetProperties();
foreach (PropertyInfo pi in oProps)
{
Type pt = pi.PropertyType;
if (pt.IsGenericType && pt.GetGenericTypeDefinition() == typeof(Nullable <>))
{
pt = System.Nullable.GetUnderlyingType(pt);
}
toReturn.Columns.Add(pi.Name, pt);
}
foreach (T rec in enumerable)
{
DataRow dr = toReturn.NewRow();
foreach (PropertyInfo pi in oProps)
{
object o = pi.GetValue(rec, null);
if (o == null)
{
dr[pi.Name] = DBNull.Value;
}
else
{
dr[pi.Name] = o;
}
}
toReturn.Rows.Add(dr);
}
return(toReturn);
}
/// <summary>
/// Convert list to Data Table
/// </summary>
/// <typeparam name="T">Target Class</typeparam>
/// <param name="varlist">list you want to convert it to Data Table</param>
/// <param name="fn">Delegate Function to Create Row</param>
/// <returns>Data Table That Represent List data</returns>
public static DataTable ToADOTable <T>(this IEnumerable <T> varlist, CreateRowDelegate <T> fn)
{
DataTable toReturn = new DataTable();
// Could add a check to verify that there is an element 0
T TopRec = varlist.ElementAtOrDefault(0);
if (TopRec == null)
{
return(toReturn);
}
// Use reflection to get property names, to create table
// column names
PropertyInfo[] oProps = ((Type)TopRec.GetType()).GetProperties();
foreach (PropertyInfo pi in oProps)
{
Type pt = pi.PropertyType;
if (pt.IsGenericType && pt.GetGenericTypeDefinition() == typeof(Nullable <>))
{
pt = Nullable.GetUnderlyingType(pt);
}
toReturn.Columns.Add(pi.Name, pt);
}
foreach (T rec in varlist)
{
DataRow dr = toReturn.NewRow();
foreach (PropertyInfo pi in oProps)
{
object o = pi.GetValue(rec, null);
if (o == null)
{
dr[pi.Name] = DBNull.Value;
}
else
{
dr[pi.Name] = o;
}
}
toReturn.Rows.Add(dr);
}
return(toReturn);
}
