/// <summary>
/// 数据实体转换类
/// </summary>
public class EntityHelper
{
/// <summary>
/// 判断DataSet默认表是否为空:true:不为空 false:为空。
/// </summary>
/// <param name="ds"></param>
/// <returns></returns>
public static bool CheckDataSet(DataSet ds)
{
bool isNull = CheckDataSet(ds, 0);
return isNull;
}
/// <summary>
/// 判断DataSet指定索引表是否为空:true:不为空 false:为空。
/// </summary>
/// <param name="ds">DataSet</param>
/// <param name="tableIndex">表的索引值</param>
/// <returns></returns>
public static bool CheckDataSet(DataSet ds, int tableIndex)
{
bool isNull = false;
if (ds != null && ds.Tables != null && ds.Tables.Count > tableIndex && ds.Tables[tableIndex] != null && ds.Tables[tableIndex].Rows != null && ds.Tables[tableIndex].Rows.Count > 0)
{
isNull = true;
}
return isNull;
}
/// <summary>
/// 根据数据表生成相应的实体对象列表
/// </summary>
/// <typeparam name="T">实体类型</typeparam>
/// <param name="srcDT">数据</param>
/// <param name="relation">数据库表列名与对象属性名对应关系；如果列名与实体对象属性名相同，该参数可为空</param>
/// <returns>对象列表</returns>
public static List<T> GetEntityListByDT<T>(DataTable srcDT, Hashtable relation)
{
List<T> list = null;
T destObj = default(T);
if (srcDT != null && srcDT.Rows.Count > 0)
{
list = new List<T>();
foreach (DataRow row in srcDT.Rows)
{
destObj = GetEntityListByDT<T>(row, relation);
list.Add(destObj);
}
}
return list;
}
/// <summary>
/// 将SqlDataReader转换成数据实体 add by trenhui
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="row"></param>
/// <param name="relation"></param>
/// <returns></returns>
public static T GetEntityListByDT<T>(SqlDataReader dr)
{
Type type = typeof(T);
T destObj = Activator.CreateInstance<T>();
foreach (PropertyInfo prop in type.GetProperties())
{
try
{
if (dr[prop.Name] != null && dr[prop.Name] != DBNull.Value)
{
SetPropertyValue(prop, destObj, dr[prop.Name]);
}
}
catch { }
}
return destObj;
}
/// <summary>
/// 将数据行转换成数据实体
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="ds"></param>
/// <returns></returns>
public static T GetEntityListByDT<T>(DataSet ds)
{
Type type = typeof(T);
T destObj = Activator.CreateInstance<T>();
try
{
DataRow row = ds.Tables[0].Rows[0];
foreach (PropertyInfo prop in type.GetProperties())
{
if (row.Table.Columns.Contains(prop.Name) &&
row[prop.Name] != DBNull.Value)
{
SetPropertyValue(prop, destObj, row[prop.Name]);
}
}
}
catch (Exception ex)
{
}
return destObj;
}
/// <summary>
/// 将数据行转换成数据实体
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="row"></param>
/// <param name="relation"></param>
/// <returns></returns>
public static T GetEntityListByDT<T>(DataRow row, Hashtable relation)
{
Type type = typeof(T);
T destObj = Activator.CreateInstance<T>();
PropertyInfo temp = null;
foreach (PropertyInfo prop in type.GetProperties())
{
if (row.Table.Columns.Contains(prop.Name) &&
row[prop.Name] != DBNull.Value)
{
SetPropertyValue(prop, destObj, row[prop.Name]);
}
}
if (relation != null)
{
foreach (string name in relation.Keys)
{
temp = type.GetProperty(relation[name].ToString());
if (temp != null &&
row[name] != DBNull.Value)
{
SetPropertyValue(temp, destObj, row[name]);
}
}
}
return destObj;
}
/// <summary>
/// 将多数据行转换成数据实体列表
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="row"></param>
/// <param name="relation"></param>
/// <returns></returns>
public static List<T> GetEntityListByDT<T>(DataRow[] rows, Hashtable relation)
{
List<T> list = null;
T destObj = default(T);
if (rows != null && rows.Length > 0)
{
list = new List<T>();
foreach (DataRow row in rows)
{
destObj = GetEntityListByDT<T>(row, relation);
list.Add(destObj);
}
}
return list;
}
/// <summary>
/// 为对象的属性赋值
/// </summary>
/// <param name="prop">属性</param>
/// <param name="destObj">目标对象</param>
/// <param name="value">源值</param>
private static void SetPropertyValue(PropertyInfo prop, object destObj, object value)
{
object temp = ChangeType(prop.PropertyType, value);
prop.SetValue(destObj, temp, null);
}
/// <summary>
/// 用于类型数据的赋值
/// </summary>
/// <param name="type">目标类型</param>
/// <param name="value">原值</param>
/// <returns></returns>
private static object ChangeType(Type type, object value)
{
int temp = 0;
if ((value == null) && type.IsGenericType)
{
return Activator.CreateInstance(type);
}
if (value == null)
{
return null;
}
if (type == value.GetType())
{
return value;
}
if (type.IsEnum)
{
if (value is string)
{
return Enum.Parse(type, value as string);
}
return Enum.ToObject(type, value);
}
if (type == typeof(bool) && typeof(int).IsInstanceOfType(value))
{
temp = int.Parse(value.ToString());
return temp != 0;
}
if (!type.IsInterface && type.IsGenericType)
{
Type type1 = type.GetGenericArguments()[0];
object obj1 = ChangeType(type1, value);
return Activator.CreateInstance(type, new object[] { obj1 });
}
if ((value is string) && (type == typeof(Guid)))
{
return new Guid(value as string);
}
if ((value is string) && (type == typeof(Version)))
{
return new Version(value as string);
}
if (!(value is IConvertible))
{
return value;
}
return Convert.ChangeType(value, type);
}
}
