來源：https://www.cnblogs.com/shiyh/p/7478241.htmlhtml
1、List<T>/IEnumerable轉換到DataTable/DataViewpost
方法一：spa
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/// <summary>
/// Convert a List{T} to a DataTable.
/// </summary>
private
DataTable ToDataTable<T>(List<T> items)
{
var
tb =
new
DataTable(
typeof
(T).Name);
PropertyInfo[] props =
typeof
(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
foreach
(PropertyInfo prop
in
props)
{
Type t = GetCoreType(prop.PropertyType);
tb.Columns.Add(prop.Name, t);
}
foreach
(T item
in
items)
{
var
values =
new
object
[props.Length];
for
(
int
i = 0; i < props.Length; i++)
{
values[i] = props[i].GetValue(item,
null
);
}
tb.Rows.Add(values);
}
return
tb;
}
/// <summary>
/// Determine of specified type is nullable
/// </summary>
public
static
bool
IsNullable(Type t)
{
return
!t.IsValueType || (t.IsGenericType && t.GetGenericTypeDefinition() ==
typeof
(Nullable<>));
}
/// <summary>
/// Return underlying type if type is Nullable otherwise return the type
/// </summary>
public
static
Type GetCoreType(Type t)
{
if
(t !=
null
&& IsNullable(t))
{
if
(!t.IsValueType)
{
return
t;
}
else
{
return
Nullable.GetUnderlyingType(t);
}
}
else
{
return
t;
}
}
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方法二：code
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public
static
DataTable ToDataTable<T>(IEnumerable<T> collection)
{
var
props =
typeof
(T).GetProperties();
var
dt =
new
DataTable();
dt.Columns.AddRange(props.Select(p =>
new
DataColumn(p.Name, p.PropertyType)).ToArray());
if
(collection.Count() > 0)
{
for
(
int
i = 0; i < collection.Count(); i++)
{
ArrayList tempList =
new
ArrayList();
foreach
(PropertyInfo pi
in
props)
{
object
obj = pi.GetValue(collection.ElementAt(i),
null
);
tempList.Add(obj);
}
object
[] array = tempList.ToArray();
dt.LoadDataRow(array,
true
);
}
}
return
dt;
}
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2、DataTable轉換到Listhtm
方法一:blog
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public
static
IList<T> ConvertTo<T>(DataTable table)
{
if
(table ==
null
)
{
return
null
;
}
List<DataRow> rows =
new
List<DataRow>();
foreach
(DataRow row
in
table.Rows)
{
rows.Add(row);
}
return
ConvertTo<T>(rows);
}
public
static
IList<T> ConvertTo<T>(IList<DataRow> rows)
{
IList<T> list =
null
;
if
(rows !=
null
)
{
list =
new
List<T>();
foreach
(DataRow row
in
rows)
{
T item = CreateItem<T>(row);
list.Add(item);
}
}
return
list;
}
public
static
T CreateItem<T>(DataRow row)
{
T obj =
default
(T);
if
(row !=
null
)
{
obj = Activator.CreateInstance<T>();
foreach
(DataColumn column
in
row.Table.Columns)
{
PropertyInfo prop = obj.GetType().GetProperty(column.ColumnName);
try
{
object
value = row[column.ColumnName];
prop.SetValue(obj, value,
null
);
}
catch
{
//You can log something here
//throw;
}
}
}
return
obj;
}
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方法二:ci
把查詢結果以DataTable返回很方便，可是在檢索數據時又很麻煩，沒有模型類型檢索方便。 string
因此不少人都是按照如下方式作的： it
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// 得到查詢結果
DataTable dt = DbHelper.ExecuteDataTable(...);
// 把DataTable轉換爲IList<UserInfo>
IList<UserInfo> users = ConvertToUserInfo(dt);
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問題：若是此係統有幾十上百個模型，那不是每一個模型中都要寫個把DataTable轉換爲此模型的方法嗎？ io
解決：能不能寫個通用類，能夠把DataTable轉換爲任何模型，呵呵，這就須要利用反射和泛型了
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using
System;
using
System.Collections.Generic;
using
System.Text;
using
System.Data;
using
System.Reflection;
namespace
NCL.Data
{
/// <summary>
/// 實體轉換輔助類
/// </summary>
public
class
ModelConvertHelper<T>
where
T :
new
()
{
public
static
IList<T> ConvertToModel(DataTable dt)
{
// 定義集合
IList<T> ts =
new
List<T>();
// 得到此模型的類型
Type type =
typeof
(T);
string
tempName =
""
;
foreach
(DataRow dr
in
dt.Rows)
{
T t =
new
T();
// 得到此模型的公共屬性
PropertyInfo[] propertys = t.GetType().GetProperties();
foreach
(PropertyInfo pi
in
propertys)
{
tempName = pi.Name;
// 檢查DataTable是否包含此列
if
(dt.Columns.Contains(tempName))
{
// 判斷此屬性是否有Setter
if
(!pi.CanWrite)
continue
;
object
value = dr[tempName];
if
(value != DBNull.Value)
pi.SetValue(t, value,
null
);
}
}
ts.Add(t);
}
return
ts;
}
}
}
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使用方式：
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// 得到查詢結果
DataTable dt = DbHelper.ExecuteDataTable(...);
// 把DataTable轉換爲IList<UserInfo>
IList<UserInfo> users = ModelConvertHelper<UserInfo>.ConvertToModel(dt);
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