有没有把IEnumerable转换成DataTable的好方法?
我可以使用反射来获取属性和值,但这似乎有点低效,有什么内置的东西吗?
(我知道下面的例子: ObtainDataTableFromIEnumerable)
编辑
这个question通知我一个处理空值的问题。
我在下面写的代码正确地处理了空值。
public static DataTable ToDataTable<T>(this IEnumerable<T> items) {
// Create the result table, and gather all properties of a T
DataTable table = new DataTable(typeof(T).Name);
PropertyInfo[] props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
// Add the properties as columns to the datatable
foreach (var prop in props) {
Type propType = prop.PropertyType;
// Is it a nullable type? Get the underlying type
if (propType.IsGenericType && propType.GetGenericTypeDefinition().Equals(typeof(Nullable<>)))
propType = new NullableConverter(propType).UnderlyingType;
table.Columns.Add(prop.Name, propType);
}
// Add the property values per T as rows to the datatable
foreach (var item in items) {
var values = new object[props.Length];
for (var i = 0; i < props.Length; i++)
values[i] = props[i].GetValue(item, null);
table.Rows.Add(values);
}
return table;
}
发布于 2009-08-10 08:36:21
看看这个:Convert List/IEnumerable to DataTable/DataView
在我的代码中,我将其更改为扩展方法:
public static DataTable ToDataTable<T>(this List<T> items)
{
var tb = new DataTable(typeof(T).Name);
PropertyInfo[] props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
foreach(var prop in props)
{
tb.Columns.Add(prop.Name, prop.PropertyType);
}
foreach (var item in items)
{
var values = new object[props.Length];
for (var i=0; i<props.Length; i++)
{
values[i] = props[i].GetValue(item, null);
}
tb.Rows.Add(values);
}
return tb;
}
发布于 2010-02-15 10:08:09
致所有人:
请注意,接受的答案中有一个与可空类型和DataTable相关的错误。可以在链接站点(http://www.chinhdo.com/20090402/convert-list-to-datatable/)或我修改后的以下代码中找到该修复程序:
///###############################################################
/// <summary>
/// Convert a List to a DataTable.
/// </summary>
/// <remarks>
/// Based on MIT-licensed code presented at http://www.chinhdo.com/20090402/convert-list-to-datatable/ as "ToDataTable"
/// <para/>Code modifications made by Nick Campbell.
/// <para/>Source code provided on this web site (chinhdo.com) is under the MIT license.
/// <para/>Copyright © 2010 Chinh Do
/// <para/>Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
/// <para/>The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
/// <para/>THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
/// <para/>(As per http://www.chinhdo.com/20080825/transactional-file-manager/)
/// </remarks>
/// <typeparam name="T">Type representing the type to convert.</typeparam>
/// <param name="l_oItems">List of requested type representing the values to convert.</param>
/// <returns></returns>
///###############################################################
/// <LastUpdated>February 15, 2010</LastUpdated>
public static DataTable ToDataTable<T>(List<T> l_oItems) {
DataTable oReturn = new DataTable(typeof(T).Name);
object[] a_oValues;
int i;
//#### Collect the a_oProperties for the passed T
PropertyInfo[] a_oProperties = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
//#### Traverse each oProperty, .Add'ing each .Name/.BaseType into our oReturn value
//#### NOTE: The call to .BaseType is required as DataTables/DataSets do not support nullable types, so it's non-nullable counterpart Type is required in the .Column definition
foreach(PropertyInfo oProperty in a_oProperties) {
oReturn.Columns.Add(oProperty.Name, BaseType(oProperty.PropertyType));
}
//#### Traverse the l_oItems
foreach (T oItem in l_oItems) {
//#### Collect the a_oValues for this loop
a_oValues = new object[a_oProperties.Length];
//#### Traverse the a_oProperties, populating each a_oValues as we go
for (i = 0; i < a_oProperties.Length; i++) {
a_oValues[i] = a_oProperties[i].GetValue(oItem, null);
}
//#### .Add the .Row that represents the current a_oValues into our oReturn value
oReturn.Rows.Add(a_oValues);
}
//#### Return the above determined oReturn value to the caller
return oReturn;
}
///###############################################################
/// <summary>
/// Returns the underlying/base type of nullable types.
/// </summary>
/// <remarks>
/// Based on MIT-licensed code presented at http://www.chinhdo.com/20090402/convert-list-to-datatable/ as "GetCoreType"
/// <para/>Code modifications made by Nick Campbell.
/// <para/>Source code provided on this web site (chinhdo.com) is under the MIT license.
/// <para/>Copyright © 2010 Chinh Do
/// <para/>Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
/// <para/>The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
/// <para/>THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
/// <para/>(As per http://www.chinhdo.com/20080825/transactional-file-manager/)
/// </remarks>
/// <param name="oType">Type representing the type to query.</param>
/// <returns>Type representing the underlying/base type.</returns>
///###############################################################
/// <LastUpdated>February 15, 2010</LastUpdated>
public static Type BaseType(Type oType) {
//#### If the passed oType is valid, .IsValueType and is logicially nullable, .Get(its)UnderlyingType
if (oType != null && oType.IsValueType &&
oType.IsGenericType && oType.GetGenericTypeDefinition() == typeof(Nullable<>)
) {
return Nullable.GetUnderlyingType(oType);
}
//#### Else the passed oType was null or was not logicially nullable, so simply return the passed oType
else {
return oType;
}
}
请注意,这两个示例都是,而不是像上面示例那样的扩展方法。
最后..。为我过多/过多的评论道歉(我被一个无礼/刻薄的教授痛打了一顿!;)
发布于 2013-02-03 03:31:49
我已经编写了一个库来为我处理这个问题。它名为DataTableProxy,可作为NuGet package使用。代码和文档在Github上
https://stackoverflow.com/questions/1253725
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