Asp.net core利用dynamic简化数据库访问
作者：天方
这篇文章介绍了Asp.net core利用dynamic简化数据库访问的方法，文中通过示例代码介绍的非常详细。对大家的学习或工作具有一定的参考借鉴价值，需要的朋友可以参考下
今天写了一个数据库的帮助类，代码如下。
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<string, object> _values = new Dictionary<string, object>(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<T>()
{
return (T)Convert.ChangeType(DbData, typeof(T));
}
public static implicit operator string(DbField data) => data.Value<string>();
public static implicit operator int(DbField data) => data.Value<int>();
public static implicit operator DateTime(DbField data) => data.Value<DateTime>();
public static implicit operator double(DbField data) => data.Value<double>();
public static implicit operator bool(DbField data) => data.Value<bool>();
}
}简单的来讲，可以把如下代码
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"]),
};
}转换为如下形式
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;
}到此这篇关于Asp.net core利用dynamic简化数据库访问的文章就介绍到这了。希望对大家的学习有所帮助，也希望大家多多支持脚本之家。