using System;
using System.Data;
using System.Data.SqlClient;
using System.Collections.Generic;
using System.Reflection;
using System.Collections;
namespace Utility
{
public static class Utility
{
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1026:DefaultParametersShouldNotBeUsed")]
public static IList<T> ToList<T>(this SqlDataReader reader, bool isNeedCloseDataReader = true) where T : class, new()
{
var resultList = new List<T>();
if (reader != null && !reader.IsClosed)
{
int columnLength = 0;
object data = null;
while (reader.Read())
{
T entity = new T();
var modelType = entity.GetType();
if (columnLength == 0)
columnLength = reader.FieldCount;
for (int i = 0; i < columnLength; i++)
{
data = reader.GetValue(i);
if (data == null || data == DBNull.Value)
continue;
var modelPropertyInfo = modelType.GetProperty(reader.GetName(i));
if (modelPropertyInfo == null)
continue;
modelPropertyInfo.SetValue(entity, data, modelPropertyInfo.GetIndexParameters());
}
resultList.Add(entity);
}
if (isNeedCloseDataReader)
{
reader.Close();
reader.Dispose();
}
}
return resultList;
}
public static IList<T> ToList<T>(this DataSet dataSet, int tableIndex) where T : class, new()
{
if (dataSet == null || dataSet.Tables.Count < 0) throw new ArgumentNullException("dataSet");
if (tableIndex > dataSet.Tables.Count - 1) return null;
if (tableIndex < 0) tableIndex = 0;
DataTable dataTable = dataSet.Tables[tableIndex];
// The return value initialization
IList<T> resultList = new List<T>();
for (int j = 0; j < dataTable.Rows.Count; j++)
{
T entity = new T();
PropertyInfo[] propertys = entity.GetType().GetProperties();
foreach (PropertyInfo pi in propertys)
{
for (int i = 0; i < dataTable.Columns.Count; i++)
{
// Attributes and field names consistent assignment
if (pi.Name.Equals(dataTable.Columns[i].ColumnName))
{
var val = dataTable.Rows[j][i];
if (val == null || val == DBNull.Value)
continue;
pi.SetValue(entity, val, null);
break;
}
}
}
resultList.Add(entity);
}
return resultList;
}
public static T ToEntity<T>(this DataRow dataRow, string[] columnNames) where T : class, new()
{
if (dataRow == null) throw new ArgumentNullException("dataRow");
if (columnNames == null || columnNames.Length == 0) throw new ArgumentNullException("columnNames");
T entity = new T();
PropertyInfo[] propertys = entity.GetType().GetProperties();
foreach (PropertyInfo pi in propertys)
{
foreach (string columnName in columnNames)
{
// Attributes and field names consistent assignment
if (pi.Name.Equals(columnName))
{
object val = dataRow[columnName];
if (val == DBNull.Value)
val = null;
pi.SetValue(entity, val, null);
break;
}
}
}
return entity;
}
public static DataTable ToDataTable(this System.Collections.IList list)
{
DataTable result = new DataTable();
Type type = null;
if (list != null)
{
if (list.Count > 0)
{
type = list[0].GetType();
}
else
{
Type[] types = list.GetType().GetGenericArguments();
if (types.Length > 0)
{
type = types[0];
}
}
}
if (type == null)
{
return result;
}
PropertyInfo[] propertys = type.GetProperties();
foreach (PropertyInfo pi in propertys)
{
Type pt = pi.PropertyType;
if (pt.IsGenericType && pt.GetGenericTypeDefinition() == typeof(Nullable<>))
pt = Nullable.GetUnderlyingType(pt);
result.Columns.Add(pi.Name, pt);
}
for (int i = 0; i < list.Count; i++)
{
ArrayList tempList = new ArrayList();
foreach (PropertyInfo pi in propertys)
{
object obj = pi.GetValue(list[i], null);
tempList.Add(obj);
}
object[] array = tempList.ToArray();
result.LoadDataRow(array, true);
}
return result;
}
}
}
DataSet,DataTable转换为list的几个实用方法
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转载自blog.csdn.net/u010833391/article/details/85052056
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