public static DataTableEntityBuilder <Entity> CreateBuilder(DataRow dataRecord)
{
DataTableEntityBuilder <Entity> dynamicBuilder = new DataTableEntityBuilder <Entity>();
DynamicMethod method = new DynamicMethod("DynamicCreateEntity", typeof(Entity), new Type[] { typeof(DataRow) }, typeof(Entity), true);
ILGenerator generator = method.GetILGenerator();
LocalBuilder result = generator.DeclareLocal(typeof(Entity));
generator.Emit(OpCodes.Newobj, typeof(Entity).GetConstructor(Type.EmptyTypes));
generator.Emit(OpCodes.Stloc, result);
for (int i = 0; i < dataRecord.ItemArray.Length; i++)
{
PropertyInfo propertyInfo = typeof(Entity).GetProperty(dataRecord.Table.Columns[i].ColumnName);
Label endIfLabel = generator.DefineLabel();
if (propertyInfo != null && propertyInfo.GetSetMethod() != null)
{
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldc_I4, i);
generator.Emit(OpCodes.Callvirt, isDBNullMethod);
generator.Emit(OpCodes.Brtrue, endIfLabel);
generator.Emit(OpCodes.Ldloc, result);
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldc_I4, i);
generator.Emit(OpCodes.Callvirt, getValueMethod);
generator.Emit(OpCodes.Unbox_Any, propertyInfo.PropertyType);
generator.Emit(OpCodes.Callvirt, propertyInfo.GetSetMethod());
generator.MarkLabel(endIfLabel);
}
}
generator.Emit(OpCodes.Ldloc, result);
generator.Emit(OpCodes.Ret);
dynamicBuilder.handler = (Load)method.CreateDelegate(typeof(Load));
return(dynamicBuilder);
}
/// <summary>
/// DataTable 转换为List 集合
/// </summary>
/// <typeparam name="TResult">类型</typeparam>
/// <param name="dt">DataTable</param>
/// <returns></returns>
//public static List<TResult> ToList<TResult>(this DataTable dt) where TResult : class, new()
//{
//#region 第一种方法
////第一种方法
////创建一个属性的列表
//List<PropertyInfo> prlist = new List<PropertyInfo>();
////获取TResult的类型实例 反射的入口
//Type t = typeof(TResult);
////获得TResult 的所有的Public 属性 并找出TResult属性和DataTable的列名称相同的属性(PropertyInfo) 并加入到属性列表
//Array.ForEach<PropertyInfo>(t.GetProperties(), p => { if (dt.Columns.IndexOf(p.Name) != -1) prlist.Add(p); });
////创建返回的集合
//List<TResult> oblist = new List<TResult>();
//foreach (DataRow row in dt.Rows)
//{
// //创建TResult的实例
// TResult ob = new TResult();
// //找到对应的数据 并赋值
// prlist.ForEach(p => { if (row[p.Name] != DBNull.Value) p.SetValue(ob, row[p.Name], null); });
// //放入到返回的集合中.
// oblist.Add(ob);
//}
//return oblist;
////*/
//#endregion
///////////////////////////////////////////////////////////
//#region 第二种方法
//第二种方法
// 定义集合
//List<TResult> ts = new List<TResult>();
//// 获得此模型的类型
//Type type = typeof(TResult);
//List<PropertyInfo> propertys = null;
//foreach (DataRow dr in dt.Rows)
//{
// TResult _t = new TResult();
// // 获得此模型的公共属性
// if (propertys == null)
// {
// propertys = new List<PropertyInfo>();
// PropertyInfo[] propertysA = _t.GetType().GetProperties();
// foreach (PropertyInfo pi in propertysA)
// {
// if (pi.CanWrite && dt.Columns.Contains(pi.Name))
// propertys.Add(pi);
// }
// }
// foreach (PropertyInfo _PropertyInfo in propertys)
// {
// object value = dr[_PropertyInfo.Name];
// if (value != DBNull.Value)
// _PropertyInfo.SetValue(_t, value, null);
// }
// ts.Add(_t);
//}
//return ts;
//#endregion
///////////////////////////////////////////////////////////
//#region 第三种方法
// List<TResult> list = new List<TResult>();
// if (dt == null || dt.Rows.Count < 1) return list;
// DataTableEntityBuilder<TResult> eblist = DataTableEntityBuilder<TResult>.CreateBuilder(dt.Rows[0]);
// foreach (DataRow info in dt.Rows) list.Add(eblist.Build(info));
// dt.Dispose(); dt = null;
// return list;
// //#endregion
//}
public static List <TResult> ToList <TResult>(this DataTable dt) where TResult : EntityBase <TResult>, new()
{
//第一种方法
//获取TResult的类型实例 反射的入口
Type t = typeof(TResult);
if (t.BaseType != typeof(EntityBase <TResult>))
{
List <TResult> list = new List <TResult>();
if (dt == null || dt.Rows.Count < 1)
{
return(list);
}
DataTableEntityBuilder <TResult> eblist = DataTableEntityBuilder <TResult> .CreateBuilder(dt.Rows[0]);
foreach (DataRow info in dt.Rows)
{
list.Add(eblist.Build(info));
}
dt.Dispose(); dt = null;
return(list);
}
else
{
//创建一个属性的列表
List <PropertyInfo2> prlist = new List <PropertyInfo2>();
Hashtable Ht = new Hashtable();
//获得TResult 的所有的Public 属性 并找出TResult属性和DataTable的列名称相同的属性(PropertyInfo) 并加入到属性列表
Array.ForEach <PropertyInfo>(t.GetProperties(), p => { if (dt.Columns.IndexOf(p.Name) != -1)
{
prlist.Add(new PropertyInfo2(p.Name));
}
});
List <TResult> oblist = new List <TResult>();
foreach (DataRow row in dt.Rows)
{
EntityBase <TResult> ob = new TResult() as EntityBase <TResult>;
ob._Prlist = prlist;
Dictionary <string, object> result = new Dictionary <string, object>();
foreach (DataColumn dc in dt.Columns)
{
result.Add(dc.ColumnName, row[dc]);
}
ob._DataRow = result;
oblist.Add(ob as TResult);
}
return(oblist);
}
}
public static List <TResult> ToList <TResult>(this DataTable dt) where TResult : class, new()
{
List <TResult> list = new List <TResult>();
if (dt == null)
{
return(list);
}
DataTableEntityBuilder <TResult> eblist = DataTableEntityBuilder <TResult> .CreateBuilder(dt.Rows[0]);
foreach (DataRow info in dt.Rows)
{
list.Add(eblist.Build(info));
}
dt.Dispose(); dt = null;
return(list);
}
public static List <T> ToListByEmit <T>(this DataTable dt) where T : class, new()
{
List <T> list = new List <T>();
if (dt == null || dt.Rows.Count == 0)
{
return(list);
}
var eblist = DataTableEntityBuilder <T> .CreateBuilder(dt.Rows[0]);
foreach (DataRow info in dt.Rows)
{
list.Add(eblist.Build(info));
}
dt.Dispose();
dt = null;
return(list);
}
/// <summary>
/// DataTable转换List
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="dt"></param>
/// <returns></returns>
public List <T> DataTableToList <T>(DataTable dt)
{
if (dt != null && dt.Rows.Count > 0)
{
List <T> list = new List <T>();
DataTableEntityBuilder <T> eblist = DataTableEntityBuilder <T> .CreateBuilder(dt.Rows[0]);
foreach (DataRow info in dt.Rows)
{
list.Add(eblist.Build(info));
}
dt.Dispose();
dt = null;
return(list);
}
else
{
return(null);
}
}
/// <summary>
/// DataRow转实体
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="dr"></param>
/// <returns></returns>
public T DataRowToEntity <T>(DataRow dr)
{
DataTableEntityBuilder <T> eblist = DataTableEntityBuilder <T> .CreateBuilder(dr);
return(eblist.Build(dr));
}
