/// <summary>
/// 将DataTable转化成List对象
/// </summary>
/// <param name="dt"></param>
/// <returns></returns>
public static List <T> ConvertToList(DataTable dt)
{
List <T> list = new List <T>();
DynamicBuilder <T> builder;
Dictionary <string, string> columns = new Dictionary <string, string>(StringComparer.InvariantCultureIgnoreCase);
#if CheckColumnExists
for (int i = 0; i < dt.Columns.Count; i++)
{
string name = dt.Columns[i].ColumnName;
if (!columns.ContainsKey(name))
{
columns.Add(name, name);
}
}
#endif
if (dictBuilderDt.ContainsKey(typeof(T)))
{
builder = dictBuilderDt[typeof(T)];
}
else
{
builder = DynamicBuilder <T> .CreateBuilder(dt.NewRow());
dictBuilderDt.Add(typeof(T), builder);
}
foreach (DataRow dr in dt.Rows)
{
list.Add(builder.BuildT(dr, columns));
}
return(list);
}
/// <summary>
/// 把IDataReader转化为List对象列表
/// </summary>
/// <param name="reader"></param>
/// <returns></returns>
public static List <T> ConvertToList(IDataReader reader)
{
List <T> list = new List <T>();
DynamicBuilder <T> builder;
Dictionary <string, string> columns = new Dictionary <string, string>(StringComparer.InvariantCultureIgnoreCase);
#if CheckColumnExists
for (int i = 0; i < reader.FieldCount; i++)
{
string name = reader.GetName(i);
if (!columns.ContainsKey(name))
{
columns.Add(name, name);
}
}
#endif
if (dictBuilder.ContainsKey(typeof(T)))
{
builder = dictBuilder[typeof(T)];
}
else
{
builder = DynamicBuilder <T> .CreateBuilder(reader);
lock (dictBuilder)
{
if (!dictBuilder.ContainsKey(typeof(T)))
{
dictBuilder.Add(typeof(T), builder);
}
}
}
while (reader.Read())
{
list.Add(builder.Build(reader, columns));
}
return(list);
}
/// <summary>
/// 创建 DataRow
/// </summary>
/// <param name="dataRecord"></param>
/// <returns></returns>
private static DynamicBuilder <T> CreateBuilder(DataRow dataRecord)
{
DynamicBuilder <T> dynamicBuilder = new DynamicBuilder <T>();
DynamicMethod method = new DynamicMethod("DynamicCreateEntity", typeof(T), new Type[] { typeof(DataRow), typeof(Dictionary <string, string>) }, 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);
PropertyInfo[] props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);
foreach (var prop in props)
{
#if CheckColumnExists
//if(dictionary.ContainsKey(prop.Name){
Label endIfLabel = generator.DefineLabel();
generator.Emit(OpCodes.Ldarg_1);
generator.Emit(OpCodes.Ldstr, prop.Name);
generator.Emit(OpCodes.Callvirt, hasColumnMethod);
generator.Emit(OpCodes.Brfalse, endIfLabel);
#endif
//if(TypeOf.IsDBNull(iDataRecord,prop.Name){
Label endIfLabel2 = generator.DefineLabel();
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldstr, prop.Name);
generator.Emit(OpCodes.Call, isDBNullMethodDT);
generator.Emit(OpCodes.Brtrue, endIfLabel2);
// Depending on the type of the property, convert the datareader column value to the type
switch (prop.PropertyType.Name)
{
case "Int16":
case "Int32":
case "Int64":
case "UInt16":
case "UInt32":
case "UInt64":
case "Byte":
case "SByte":
case "Boolean":
case "String":
case "DateTime":
case "Single":
case "Double":
case "Decimal":
case "Char":
// Load the T instance, SqlDataReader parameter and the field name onto the stack
generator.Emit(OpCodes.Ldloc_0);
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldstr, prop.Name);
// Push the column value onto the stack
generator.Emit(OpCodes.Callvirt, getValueMethodDT);
//Convert Common Type
generator.Emit(OpCodes.Call, typeof(Convert).GetMethod("To" + prop.PropertyType.Name, new Type[] { typeof(object) }));
break;
case "Nullable`1":
// Load the T instance, SqlDataReader parameter and the field name onto the stack
generator.Emit(OpCodes.Ldloc_0);
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldstr, prop.Name);
// Push the column value onto the stack
generator.Emit(OpCodes.Callvirt, getValueMethodDT);
//Convert Nullable Type
generator.Emit(OpCodes.Unbox_Any, prop.PropertyType);
break;
default:
#if CheckColumnExists
generator.MarkLabel(endIfLabel);
//}
#endif
generator.MarkLabel(endIfLabel2);
// Don't set the field value as it's an unsupported type
continue;
}
generator.Emit(OpCodes.Callvirt, prop.GetSetMethod());
//}
generator.MarkLabel(endIfLabel2);
#if CheckColumnExists
generator.MarkLabel(endIfLabel);
//}
#endif
}
generator.Emit(OpCodes.Ldloc, result);
generator.Emit(OpCodes.Ret);
dynamicBuilder.handlerT = (LoadT)method.CreateDelegate(typeof(LoadT));
return(dynamicBuilder);
}