public static class DataTableHelper
{
/// /// 将datatable转换为泛型集合 ///
///
///
///
public static List ToList(this DataTable inputDataTable) where TEntity : class, new()
{
if (inputDataTable == null)
{
throw new ArgumentNullException(“input datatable is null”);
}
Type type = typeof(TEntity);
PropertyInfo[] propertyInfos = type.GetProperties();
List lstEntitys = new List();
foreach (DataRow row in inputDataTable.Rows)
{
object obj = Activator.CreateInstance(type);
foreach (PropertyInfo pro in propertyInfos)
{
foreach (DataColumn col in inputDataTable.Columns)
{
//如果直接查询的数据库，数据库是不区别大小写的，所以转换为小写忽略大小写的问题
if (col.ColumnName.ToLower().Equals(pro.Name.ToLower()))
{
//属性是否是可写的，如果是只读的属性跳过。
if (pro.CanWrite)
{
//判断类型，基本类型，如果是其他的类属性
if (pro.PropertyType == typeof(System.Int32))
{
pro.SetValue(obj, Convert.ToInt32(row[pro.Name.ToLower()]));
}
else if (pro.PropertyType == typeof(System.String))
{
pro.SetValue(obj, row[pro.Name.ToLower()].ToString());
}
else if (pro.PropertyType == typeof(System.Boolean))
{
pro.SetValue(obj, Convert.ToBoolean(row[pro.Name.ToLower()]));
}
else if (pro.PropertyType == typeof(System.DateTime))
{
pro.SetValue(obj, Convert.ToDateTime(row[pro.Name.ToLower()]));
}
else if (pro.PropertyType == typeof(System.Int64))
{
pro.SetValue(obj, Convert.ToInt64(row[pro.Name.ToLower()]));
}
else
{
pro.SetValue(obj, row[pro.Name.ToLower()]);
}
/// /// DataTable转成List ///
public static List ToDataList(this DataTable dt)
{
var list = new List();
var plist = new List(typeof(T).GetProperties());
if (dt == null || dt.Rows.Count == 0)
{
return null;
}
foreach (DataRow item in dt.Rows)
{
T s = Activator.CreateInstance<T>();
for (int i = 0; i < dt.Columns.Count; i++)
{
PropertyInfo info = plist.Find(p => p.Name == dt.Columns[i].ColumnName);
if (info != null)
{
try
{
if (!Convert.IsDBNull(item[i]))
{
object v = null;
if (info.PropertyType.ToString().Contains("System.Nullable"))
{
v = Convert.ChangeType(item[i], Nullable.GetUnderlyingType(info.PropertyType));
}
else
{
v = Convert.ChangeType(item[i], info.PropertyType);
}
info.SetValue(s, v, null);
}
}
catch (Exception ex)
{
throw new Exception("字段[" + info.Name + "]转换出错," + ex.Message);
}
}
}
list.Add(s);
}
return list;
}
/// <summary>
/// DataTable转成实体对象
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="dt"></param>
/// <returns></returns>
public static T ToDataEntity<T>(this DataTable dt)
{
T s = Activator.CreateInstance<T>();
if (dt == null || dt.Rows.Count == 0)
{
return default(T);
}
var plist = new List<PropertyInfo>(typeof(T).GetProperties());
for (int i = 0; i < dt.Columns.Count; i++)
{
PropertyInfo info = plist.Find(p => p.Name == dt.Columns[i].ColumnName);
if (info != null)
{
try
{
if (!Convert.IsDBNull(dt.Rows[0][i]))
{
object v = null;
if (info.PropertyType.ToString().Contains("System.Nullable"))
{
v = Convert.ChangeType(dt.Rows[0][i], Nullable.GetUnderlyingType(info.PropertyType));
}
else
{
v = Convert.ChangeType(dt.Rows[0][i], info.PropertyType);
}
info.SetValue(s, v, null);
}
}
catch (Exception ex)
{
throw new Exception("字段[" + info.Name + "]转换出错," + ex.Message);
}
}
}
return s;
}
/// <summary>
/// List转成DataTable
/// </summary>
/// <typeparam name="T">实体类型</typeparam>
/// <param name="entities">实体集合</param>
public static DataTable ToDataTable<T>(List<T> entities)
{
if (entities == null || entities.Count == 0)
{
return null;
}
var result = CreateTable<T>();
FillData(result, entities);
return result;
}
/// <summary>
/// 创建表
/// </summary>
private static DataTable CreateTable<T>()
{
var result = new DataTable();
var type = typeof(T);
foreach (var property in type.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance))
{
var propertyType = property.PropertyType;
if ((propertyType.IsGenericType) && (propertyType.GetGenericTypeDefinition() == typeof(Nullable<>)))
propertyType = propertyType.GetGenericArguments()[0];
result.Columns.Add(property.Name, propertyType);
}
return result;
}
/// <summary>
/// 填充数据
/// </summary>
private static void FillData<T>(DataTable dt, IEnumerable<T> entities)
{
foreach (var entity in entities)
{
dt.Rows.Add(CreateRow(dt, entity));
}
}
/// <summary>
/// 创建行
/// </summary>
private static DataRow CreateRow<T>(DataTable dt, T entity)
{
DataRow row = dt.NewRow();
var type = typeof(T);
foreach (var property in type.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance))
{
row[property.Name] = property.GetValue(entity) ?? DBNull.Value;
}
return row;
}
}
}
}
}
TEntity tEntity = obj as TEntity;
lstEntitys.Add(tEntity);
}
return lstEntitys;
}
/// <summary>
/// 将list转换为datatable
/// </summary>
/// <typeparam name="TEntity"></typeparam>
/// <param name="inputList"></param>
/// <returns></returns>
public static DataTable ToDataTable<TEntity>(this List<TEntity> inputList) where TEntity : class, new()
{
if (inputList == null)
{
throw new ArgumentNullException("inputList");
}
DataTable dt = null;
Type type = typeof(TEntity);
if (inputList.Count == 0)
{
dt = new DataTable(type.Name);
return dt;
}
else { dt = new DataTable(); }
PropertyInfo[] propertyInfos = type.GetProperties();
foreach (var item in propertyInfos)
{
dt.Columns.Add(new DataColumn() { ColumnName = item.Name, DataType = item.PropertyType });
}
foreach (var item in inputList)
{
DataRow row = dt.NewRow();
foreach (var pro in propertyInfos)
{
row[pro.Name] = pro.GetValue(item);
}
dt.Rows.Add(row);
}
return dt;
}
