如何使用dynamic
DataTable dt = new DataTable("TableOne");
dt.Columns.Add("ID", typeof(int));
dt.Columns.Add("Name", typeof(string));
dt.Columns.Add("Age", typeof(int));
dt.Rows.Add(1, "zyb", 24);
dt.Rows.Add(2, "sjn", 22);
dt.Rows.Add(3, "zybsjn", 46);
string name = string.Empty;
List<dynamic> dylit = new List<dynamic>();
foreach (DataRow row in dt.Rows)
{
dynamic dy = new DynamicData();
foreach (DataColumn col in dt.Columns)
{
dy[col.ColumnName] = row[col.ColumnName];
}
dylit.Add(dy);
}
实例化dynamic前需要写一个类,该类继承自DynamicObject如下:
public class DynamicData : DynamicObject
{
/// <summary>
/// 内置集合参数
/// </summary>
private readonly Dictionary<string, object> _objEntity = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
/// <summary>
/// Provides the implementation of getting a member. Derived classes can override
/// this method to customize behavior. When not overridden the call site requesting the
/// binder determines the behavior.
/// </summary>
/// <param name="binder">The binder provided by the call site.</param>
/// <param name="result">The result of the get operation.</param>
/// <returns>true if the operation is complete, false if the call site should determine behavior.</returns>
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
//object objValue;
//_objEntity.TryGetValue(binder.Name, out objValue);
//result = objValue;
_objEntity.TryGetValue(binder.Name, out result);
return true;
}
/// <summary>
/// Provides the implementation of setting a member. Derived classes can override
/// this method to customize behavior. When not overridden the call site requesting the
/// binder determines the behavior.
/// </summary>
/// <param name="binder">The binder provided by the call site.</param>
/// <param name="value">The value to set.</param>
/// <returns>true if the operation is complete, false if the call site should determine behavior.</returns>
public override bool TrySetMember(SetMemberBinder binder, object value)
{
//Dictionary<string, object>总是可以设置value,不管key存不存在
_objEntity[binder.Name] = value;
return true;
}
/// <summary>
/// 返回所有动态成员的Name的列表
/// </summary>
/// <returns>动态成员名称的列表</returns>
public override IEnumerable<string> GetDynamicMemberNames()
{
return _objEntity.Keys;
}
/// <summary>
/// 通过动态类型的成员名称获取值
/// </summary>
/// <param name="name">成员的名称</param>
/// <returns>该成员的值,key不存在时返回null</returns>
public object this[string name]
{
get
{
object value;
_objEntity.TryGetValue(name, out value);
return value;
}
set
{
_objEntity[name] = value;
}
}
}
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