/// <summary>
/// DataReader转换为list
/// </summary>
/// <typeparam name="T">要转换的类型</typeparam>
/// <param name="reader">DataReader对象</param>
/// <returns></returns>
public static IList <T> DataReaderToList <T>(IDataReader reader) where T : new()
{
DynamicBuilder <T> builder = DynamicBuilder <T> .CreateBuilder(reader);
IList <T> list = new List <T>();
while (reader.Read())
{
list.Add(builder.Build(reader));
}
reader.Close();
return(list);
}
/// <summary>
/// DataReader转换为实体
/// </summary>
/// <typeparam name="T">转换的类型</typeparam>
/// <param name="reader">DataReader对象</param>
/// <returns></returns>
public static T DataReaderToObject <T>(IDataReader reader) where T : new()
{
var obj = new T();
if (reader.Read())
{
DynamicBuilder <T> builder = DynamicBuilder <T> .CreateBuilder(reader);
obj = builder.Build(reader);
}
else
{
obj = default(T);
}
reader.Close();
return(obj);
}
public static DynamicBuilder <T> CreateBuilder(IDataRecord dataRecord)
{
var dynamicBuilder = new DynamicBuilder <T>();
var method = new DynamicMethod("DynamicCreate", typeof(T), new[] { typeof(IDataRecord) }, typeof(T), true);
ILGenerator generator = method.GetILGenerator();
LocalBuilder result = generator.DeclareLocal(typeof(T));
generator.Emit(OpCodes.Newobj, typeof(T).GetConstructor(Type.EmptyTypes));
generator.Emit(OpCodes.Stloc, result);
for (int i = 0; i < dataRecord.FieldCount; i++)
{
PropertyInfo propertyInfo = typeof(T).GetProperty(dataRecord.GetName(i),
BindingFlags.Instance | BindingFlags.Public |
BindingFlags.IgnoreCase);
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, dataRecord.GetFieldType(i));
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);
}
