Asp.net core利用dynamic简化数据库访问_实用技巧_

public static class DbEx { public static dynamic ReadToObject(this IDataReader reader) { var obj = new DbObject(); for (int i = 0; i < reader.FieldCount; i++) { obj[reader.GetName(i)] = new DbField() { DbData = reader[i] }; } return obj; } public class DbObject : DynamicObject { //自己实现一个，不用ExpandoObject， 以支持无视大小写读取 public override bool TryGetMember(GetMemberBinder binder, out object result) { result = this[binder.Name]; return true; } Dictionary _values = new Dictionary(StringComparer.CurrentCultureIgnoreCase); public object this[string index] { get => _values[index]; set => _values[index] = value; } } public class DbField { public object DbData { get; set; } public T Value() { return (T)Convert.ChangeType(DbData, typeof(T)); } public static implicit operator string(DbField data) => data.Value(); public static implicit operator int(DbField data) => data.Value(); public static implicit operator DateTime(DbField data) => data.Value(); public static implicit operator double(DbField data) => data.Value(); public static implicit operator bool(DbField data) => data.Value(); } }

GpsData parse(IDataReader reader) { return new GpsData() { IsValid = (bool)reader["IsValid"], Location = new Location () { Lon = (double)reader["Lon"], Lat = (double)reader["Lat"], }, Angle = (double)reader["Angle"], Speed = (double)reader["Speed"]), UpdateTime = (double)reader["Speed"]), }; }

GpsData parse(IDataReader reader) { var obj = reader.ReadToObject(); var state = new GpsData() { IsValid = obj.IsValid, Location = new Location() { Lon = obj.Lon, Lat = obj.Lat, }, Angle = obj.Angle, Speed = obj.Speed, UpdateTime = obj.UpdateTime, }; return state; }