Go C # Reflection, binding database query data and entity classes based on reflection, no entity class assignment

This article from: http://www.cnblogs.com/mrchenzh/archive/2010/05/31/1747937.html

/*****************************************
* Description: Use reflection to automatically bind the contents of a database query
* To entity class
*
* Time: 1:49 2009-9-19
*
* Programmer: Wang Wenjung
* ***************************************/
/**************** Database Script ***************
* CREATE DATABASE MySchool
* Go
* Use MySchool
* Go
* CREATE TABLE Student
* (
* ID int Identity primary KEY,
* Name varchar (10)
* )
* ****************************************/
Using System;
Using System.Reflection;
Using System.Data.SqlClient;
Using System.Data;
Using System.Collections.Generic;

Namespace Reflectiondemo
{
#region Main
Class Program
{
static void Main (string[] args)
{
DataSet ds = new DataSet ();

Building a DataSet #region connection database

SqlConnection con = new SqlConnection ("Data source=.;i Nitial catalog=myschool;integrated security=true ");
SqlDataAdapter objadapter = new SqlDataAdapter ("SELECT * from student", con);
Objadapter.fill (DS);

#endregion

#region Build a DataSet manually

DataTable dt = new DataTable ();
Dt. Columns.Add ("ID");
Dt. Columns.Add ("Name");
DataRow row = dt. NewRow ();
row["ID"] = 1;
row["Name"] = "grey too Wolf";
Dt. Rows.Add (row);
Ds. Tables.add (DT);
#endregion

list<student> students = new list<student> ();
foreach (DataRow DataRow in DS. Tables[0]. Rows)
{
Student stu = new Student ();
Utility.converttoentity (Stu, Row);
Students. ADD (Stu);
}
foreach (Student Student in students)
{
Console.WriteLine (student. Name);
}
}
}
#endregion

#region Entity Classes

<summary>
Entity class that needs to be in the property
Add custom attributes on
Each entity class corresponds to the data table
A field, note that the parameters in the custom attribute
Be sure to correspond to field one by one in the data table,
Otherwise it will not be reflected!
</summary>
public class Student
{
[Datacontextattribute ("ID")]
public int ID {get; set;}
[DataContext ("Name")]
public string Name {get; set;}
}

#endregion

#region Custom Attributes

<summary>
Custom Attributes
</summary>
[AttributeUsage (Attributetargets.property)]
public class Datacontextattribute:attribute
{
<summary>
Custom Attributes
</summary>
<param name= "FieldName" > Data table field name </param>
Public Datacontextattribute (string property) {this. Property = property; }
<summary>
Data table field properties (Entity properties)
</summary>
public string Property {get; set;}
}

#endregion

#region Reflection

public class Utility
{
<summary>
Convert a DataRow into an entity
</summary>
<param name= "obj" > Entities </param>
<param name= "Row" > Data table row Data </param>
public static void Converttoentity (Object obj, DataRow row)
{
Get the type of obj
Type type = obj. GetType ();
Returns all public properties of this type
propertyinfo[] Infos = type. GetProperties ();
Looping Public Property arrays
foreach (PropertyInfo info in infos)
{
Returns an array of custom attributes
object[] Attributes = info. GetCustomAttributes (typeof (Datacontextattribute), false);
Looping a custom property array
foreach (Datacontextattribute attribute in attributes)
{
If this column is included in the DataRow
if (row. Table.Columns.Contains (attribute. property))
{
Assigns the value of the DataRow specified column
Object value = Row[attribute. Property];
Returns if value is null
if (value = = DBNull.Value) continue;
Convert a value
if (info. Propertytype.equals (typeof (String)))
{
Value = Row[attribute. Property]. ToString ();
}
else if (info. Propertytype.equals (typeof (int)))
{
Value = Convert.ToInt32 (Row[attribute. Property]);
}
else if (info. Propertytype.equals (typeof (decimal)))
{
Value = Convert.todecimal (Row[attribute. Property]);
}
else if (info. Propertytype.equals (typeof (DateTime)))
{
Value = Convert.todatetime (Row[attribute. Property]);
}
else if (info. Propertytype.equals (typeof (Double)))
{
Value = Convert.todouble (Row[attribute. Property]);
}
else if (info. Propertytype.equals (typeof (BOOL)))
{
Value = Convert.toboolean (Row[attribute. Property]);
}
Use reflection to automatically assign value to the corresponding public property of obj
Info. SetValue (obj, value, null);
}
}
}
}
}

#endregion
}

Go C # Reflection, binding database query data and entity classes based on reflection, no entity class assignment