public static DataTable ToDataTable <T>(this IEnumerable <T> entities)
{
if (entities == null || entities.Count() == 0)
{
return(null);
}
DataTable result = new DataTable();
var infos = typeof(T).GetProperties().ToDictionary(p => p.Name);
if (TableAttribute.TryGetTableAttribute <T>(out TableAttribute tableAttribute))
{
result.TableName = tableAttribute.TableName;
}
else
{
result.TableName = typeof(T).Name;
}
if (ColumnAttribute.TryGetColumnAttributes <T>(out Dictionary <PropertyInfo, ColumnAttribute> columnAttributes))
{
//设置表头
List <DataColumn> keys = new List <DataColumn>();
foreach (var att in columnAttributes)
{
var value = att.Value;
DataColumn column = new DataColumn()
{
ColumnName = value.ColumnName ?? att.Key.Name,
Caption = value.Description,
AllowDBNull = value.Nullable,
AutoIncrement = value.IsIdentity,
DataType = infos[att.Key.Name].PropertyType,
Unique = value.Unique,
};
if (column.DataType == typeof(string) && value.Length > 0)
{
column.MaxLength = value.Length;
}
if (Leo.Util.Converter.TryParse(value.DefaultVal, infos[att.Key.Name].PropertyType, out object obj))
{
column.DefaultValue = obj;
}
if (value.IsPrimaryKey)
{
keys.Add(column);
}
result.Columns.Add(column);
}
result.PrimaryKey = keys.ToArray();
//设置值
foreach (var entity in entities)
{
var row = result.NewRow();
foreach (var att in columnAttributes)
{
var value = att.Value;
row[value.ColumnName ?? att.Key.Name] = infos[att.Key.Name].GetValue(entity);
}
result.Rows.Add(row);
}
}
return(result);
}
