C#教程之c#中利用委托反射将DataTable转换为实体集

当前位置:

首页 > 编程开发 > 汇编语言 >

C#教程之c#中利用委托反射将DataTable转换为实体集

c#中利用委托反射将DataTable转换为实体集的代码，需要的朋友可以参考下类泛型的约束：

复制代码代码如下:

public static class ToModel<T> where T : class, new()

定义委托：

复制代码代码如下:

public delegate void SetString(string value);

创建委托方法：

复制代码代码如下:

private static SetString CreateStringDelegate(T model, string propertyName)

{

MethodInfo mi = model.GetType().GetProperty(propertyName).GetSetMethod();

Type type = typeof(SetString);

return Delegate.CreateDelegate(type, model, mi) as SetString;

}

利用反射和委托将DataTable转换为实体集：

复制代码代码如下:

public static IList<T> GetDelegate_ToModelList(DataTable dt)

{

IList<T> list = new List<T>();

if (dt == null || dt.Rows.Count < 1) return list;

SetString setDelegateString;

foreach (DataRow dr in dt.Rows)

{

T model = new T();

foreach (DataColumn dc in dt.Columns)

{

setDelegateString = CreateStringDelegate(model, dc.ColumnName);

setDelegateString(dr[dc.ColumnName].ToString());

}

list.Add(model);

}

return list;

}

这样写问题就来了，因为委托定义的参数时string类型的，因为我们实体中可能有int或者DateTime类型的，这时就需要用上泛型委托了
如果这样定义委托：

复制代码代码如下:

public delegate void SetString<PT>(PT value)

创建委托方法（这里有问题，不知如何处理）：

复制代码代码如下:

private static SetString CreateStringDelegate(T model, string propertyName)

{

MethodInfo mi = model.GetType().GetProperty(propertyName).GetSetMethod();

Type type = typeof(model).GetProperty(propertyName).PropertyType;

return Delegate.CreateDelegate(type, model, mi) as SetString<type>;

}

利用反射和委托将DataTable转换为实体集：

复制代码代码如下:

public static IList<T> GetDelegate_ToModelList(DataTable dt)

{

IList<T> list = new List<T>();

if (dt == null || dt.Rows.Count < 1) return list;

foreach (DataRow dr in dt.Rows)

{

T model = new T();

foreach (DataColumn dc in dt.Columns)

{

SetString<typeof(T).GetProperty(dc.ColumnName).PropertyType> setDelegateString = CreateStringDelegate(model, dc.ColumnName);

setDelegateString(dr[dc.ColumnName].ToString());

}

list.Add(model);

}

return list;

}

一直疑惑着，希望有人帮我解决疑惑，直接反射的方法我也有，但是这个问题不解决，心里一直有疙瘩，希望有人帮帮忙，谢谢
泛型可以动态构建的，你了解了这个，就能解决了，附上我的简略代码：

复制代码代码如下:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Data;

using System.Reflection;

namespace RftToModel {

class Program {

static void Main(string[] args) {

var result = ToModel<TestModel>.GetDelegate_ToModelList(BuildSampleTable());

foreach (var item in result) {

Console.WriteLine(item);

}

Console.Read();

}

static DataTable BuildSampleTable() {

DataTable result = new DataTable();

result.Columns.Add("ID", typeof(int));

result.Columns.Add("Name", typeof(string));

result.Columns.Add("IsDeleted", typeof(bool));

result.Rows.Add(new object[] { 1, "M.K", false });

result.Rows.Add(new object[] { 2, "B.G", true });

return result;

}

}

public class TestModel {

public int ID { get; set; }

public string Name { get; set; }

public bool IsDeleted { get; set; }

public override string ToString() {

return string.Format("ID:{0} Name:{1} IsDeleted:{2}", ID, Name, IsDeleted);

}

}

public delegate void SetValue<T>(T value);

public static class ToModel<T> where T : class, new() {

private static Delegate CreateSetDelegate(T model, string propertyName) {

MethodInfo mi = model.GetType().GetProperty(propertyName).GetSetMethod();

//这里构造泛型委托类型

Type delType = typeof(SetValue<>).MakeGenericType(GetPropertyType(propertyName));

return Delegate.CreateDelegate(delType, model, mi);

}

private static Type GetPropertyType(string propertyName) {

return typeof(T).GetProperty(propertyName).PropertyType;

}

public static IList<T> GetDelegate_ToModelList(DataTable dt) {

IList<T> list = new List<T>();

if (dt == null || dt.Rows.Count < 1) return list;

Delegate setDelegate;

foreach (DataRow dr in dt.Rows) {

T model = new T();

foreach (DataColumn dc in dt.Columns) {

setDelegate = CreateSetDelegate(model, dc.ColumnName);

//这里改变类型

setDelegate.DynamicInvoke(Convert.ChangeType(dr[dc.ColumnName], GetPropertyType(dc.ColumnName)));

}

list.Add(model);

}

return list;

}

}

}

栏目列表