help.txt

使用工具为.net2003

MVC architecture in ASP.net using C# and Microsoft Data Access Application block
In this article we will learn how to use Microsoft Data Access Application block 
in asp.net using C#. 

What is Microsoft Data Access Application Block?
It consist of single .Net based assembly, which contains all of the functionalities 
necessary to perform the most common data access task against microsoft SQL SERVER 7/2000
database.
Specifically the data access application block helps us in following:
1.	Calls stored procedure or SQL text command
2.	Specify parameter detail
3.	Return SqlDataReader, DataSet, XMLDataReader objects or signle values

In general Data Access Application block is designed to encapsulate microsofts recommended
best practices for data access.

What you can achieve with the use of Microsoft Data Access Application Block?
A)	Minimize the dataaccess code you need to write often to single line.
B)	Ensures that your data access logic is implemented in an effecient and effective
	manner.
Mainly it has got SqlHelper class provides set of static mehtods which you can use to 
execute a varity of different command types against the database.

DataBase work to do as below:

-- Table Creation
create table tbl_Member
(
	memberId	Int	primary key	identity(1,1) Not Null,
	firstName	varchar(50)	Not Null,
	lastName	varchar(50)	Not Null,
	contactNo	varchar(15)	Not Null,
	emailAddress	varchar(70)	Not Null
)
-- Stored Procedure Creation
create procedure usps_proInsMember
(
	@fName varchar(50),@lName varchar(50),@coNo varchar(15),@emailAddr varchar(70)	
)
AS 
INSERT INTO tbl_Member (firstName,lastName,contactNo,emailAddress)
VALUES(@fName,@lName,@coNo,@emailAddr)

-- Procedure to listAllMember
create procedure usps_proSelectMember
AS
SELECT * FROM tbl_Member

-- exec usps_proInsMember 'Munir','Shaikh','23423423','[e-mail]'
-- SELECT * FROM tbl_Member

What is MVC archeticture?

Let us start with actual topic as how to implement MVC with asp.net and c#
I will assume that you have installed Microsoft Data Access Block For .Net on your machine
you can download form microsoft site.

Follw the steps as 
Create new project with name "Mvc"
>>Right click on solution
	>>Add 
		>>New Project
		Select Class Library under Visual C# project
		Give Library Name as: AbstractLayer

Similarly you need to follow above steps for "BusinessLayer" and "DataLayer" please refer to the image
for the solution explorer how it look like.

In short we have added Three different libraries to MVC project, each these libraries themself
are acting as signle project.
Now let us follwo steps to add references of these class libraries
>>Right click on Business Layer
	>>Add References
		>>Under Project Tab
		>>Select Abstract Layer and Select Data Layer
		Click on ok, and references get added to the selected library
Similarly follow the steps for datalayer and add reference of Abstractlayer

STEPI:
Let us discuss what is AbstractLayer in our project?
In this project as we are dealing with the Member's basic functionalities like 
1.	AddnewMember	
2.	MemberList
In short i will call "ExecuteNonQuery" and "ExecuteDataset" methods from Microsoft Data
access Application block for .net

so all the getter and setter methods will be there in this which we can derive from the class and 
use it while passing to object
So let us add class to AbstractLayer called as "baseMember.cs" which will hold all the getter and setter methods
As this class is acting as abstract so we need access above method by deriving this class in the 
"DataLayer"

STEPII:
so let us have a look at DataLayer class library, we will add a class called as 
"Member.cs" which is derived from  baseMember main aim is to pass object to the respective methods
So entire code of this page look like below

using System;
using System.Data;
using System.Data.SqlClient;
using AbstractLayer;
using DataLayer;
namespace BusinessLayer
{
	/// <summary>
	/// Summary description for Member.
	/// </summary>
	public class Member : baseMember
	{
		public int AddnewMember(AbstractLayer.baseMember objMember)
		{
			IdataAccess MemberSqlDataAccess = new SqlDataAccess(System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"].ToString());
			return MemberSqlDataAccess.AddnewMember(objMember);
		}
		public DataSet MemberList()
		{
			DataSet dtSt;
			IdataAccess MemberListSqlDataAccess = new SqlDataAccess(System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"].ToString());
			dtSt = MemberListSqlDataAccess.ListAllMembers();
			return dtSt;
		}
	}
}


STEPIII:(when you install Microsoft Data Access Application block, you can find SqlHelper.cs to following location
under program files\Microsoft Application Blocks for .NET\Data Access\Code\CS\Microsoft.ApplicationBlocks.Data\SQLHelper.cs
)

DataLayer:
Copy SqlHelper.cs from above path and add under "DataLayer" in our project
We will add class called as "IdataAccess.cs" in "DataLayer" is basically acting as an interface
code goes as below
using System;
using System.Data;
using AbstractLayer;
namespace DataLayer
{
	/// <summary>
	/// Summary description for IdataAccess.
	/// </summary>
	public interface IdataAccess
	{
		//all the method signature goes here		
		int AddnewMember(AbstractLayer.baseMember  objMember);
		DataSet ListAllMembers();
	}
}
which will hold all the signatures to implement this interface signature we have to have another class so we will add 
another class "SqlDataAccess.cs" under the same layer
Code goes as below
using System;
using Microsoft.ApplicationBlocks.Data;
using AbstractLayer;
using System.Data;
using System.Data.SqlClient;
namespace DataLayer
{
	/// <summary>
	/// Summary description for sqlDataAccess.
	/// </summary>
	public class SqlDataAccess : IdataAccess
	{
		// All the implementation of signatures goes here 
		string m_Connection_String=System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"].ToString();
		public SqlDataAccess(string _ConnectionString)
		{
			m_Connection_String=_ConnectionString;	
		}
		public int AddnewMember(AbstractLayer.baseMember  objMember)
		{
			SqlTransaction objTrans=null;						
			SqlConnection myConnection =  new SqlConnection(m_Connection_String);
			try
			{
				// Insert Member Personal details only
				myConnection.Open();
				objTrans= myConnection.BeginTransaction();
				SqlParameter [] arrParam=new SqlParameter[4];

				arrParam[0]=new SqlParameter("@fName", objMember.firstName); 
				arrParam[1]=new SqlParameter("@lName",objMember.lastName);
				arrParam[2]=new SqlParameter("@coNo",objMember.contactNo);
				arrParam[3]=new SqlParameter("@emailAddr",objMember.emailAddress);
				//pass connection string, storedprocedure name and parameter array
				SqlHelper.ExecuteNonQuery(m_Connection_String,CommandType.StoredProcedure,"usps_proInsMember",arrParam);
				
			}
			catch(Exception Ex)
			{	
				objTrans.Rollback();
				string sError=Ex.Message.ToString();  
				return -1;
			}
			finally
			{
				myConnection.Close(); 
			}
			return 1;
		}
		public DataSet ListAllMembers()
		{
			DataSet dtStMembers;
			dtStMembers = SqlHelper.ExecuteDataset(m_Connection_String,CommandType.StoredProcedure,"usps_proSelectMember");
			return dtStMembers;
		}
	}
}
Note We are making use of "Microsoft.ApplicationBlocks.Data" namespace in above class 
Now so far so good till now we have taken care of abstractlayer, businesslayer & Datalayers
Now let us discuss about our design i.e. HTML (Inline coding)
As this deals with look and feel so we will add folder "View" under "MVC" project
and to peroform Addition of new member we will add "AddMember.aspx" file, which is basically
Member Screen through which input values will be supplied
Now let us look at the code behid of the above page
basically we will instantiate the business class as 
protected BusinessLayer.Member objMember = new BusinessLayer.Member();
and pass value as an object.

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace Mvc
{
	/// <summary>
	/// Summary description for WebForm1.
	/// </summary>
	public class WebForm1 : System.Web.UI.Page
	{
		protected System.Web.UI.WebControls.Button btnSave;
		protected System.Web.UI.WebControls.TextBox txtFirstName;
		protected System.Web.UI.WebControls.TextBox txtLastName;
		protected System.Web.UI.WebControls.TextBox txtContactNo;
		protected System.Web.UI.WebControls.TextBox txtEmailAddress;
		protected System.Web.UI.WebControls.Label lblMessage;
		protected BusinessLayer.Member objMember = new BusinessLayer.Member();
		private void Page_Load(object sender, System.EventArgs e)
		{
			// Put user code to initialize the page here
		}

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN: This call is required by the ASP.NET Web Form Designer.
			//
			InitializeComponent();
			base.OnInit(e);
		}
		
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{    
			this.btnSave.Click += new System.EventHandler(this.btnSave_Click);
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion

		private void btnSave_Click(object sender, System.EventArgs e)
		{
			AddMember();
			int retVal = objMember.AddnewMember(objMember);
			if(retVal>0)
			{
				lblMessage.Text = "New record added successfully";
			}
			else
			{
				lblMessage.Text = "An error has occured while processing your request";
			}
		}
		public void AddMember()
		{
			objMember.firstName = txtFirstName.Text.Trim();
			objMember.lastName = txtLastName.Text.Trim();
			objMember.contactNo = txtContactNo.Text.Trim();
			objMember.emailAddress = txtEmailAddress.Text.Trim();
		}
	}
}
This will take care of your "Add New Member"

similarly we can add "MemberList.aspx" under "View" folder and add datagrid to this page
To display the member list code goes as below
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace Mvc.View
{
	/// <summary>
	/// Summary description for MemberList.
	/// </summary>
	public class MemberList : System.Web.UI.Page
	{
		protected System.Web.UI.WebControls.DataGrid dtGrdMember;
		protected BusinessLayer.Member objMember = new BusinessLayer.Member();

		private void Page_Load(object sender, System.EventArgs e)
		{
			// Put user code to initialize the page here
			if (!Page.IsPostBack)
			{
				//To load DataGrid Code goes here
				DataSet dtSt;
				dtSt = objMember.MemberList();
				dtGrdMember.DataSource = dtSt;
				dtGrdMember.DataBind();
			}
		}

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN: This call is required by the ASP.NET Web Form Designer.
			//
			InitializeComponent();
			base.OnInit(e);
		}
		
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{    
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion
	}
}

And that's all
As normal developer you will always think that this is very big and vast procedure, but remember
the benigits.

Advantages:

1.	Code will be seperated from the Data layer due to which it will be very easy to maintain
	for the logng run of the project, as every system kepp on going under modification / enhancement
	so at that time you will have to just go on adding view files and signature in the interface and it's implementation

2.	Easy to understand and code transfer. i.e. when want to implenment at client's server
	you just need to upload view files and dll fiels.

3.	It increases the system performance as there is no need to do connection pooling etc. 
4.	Easy to maintain documentation

I have implemented above MVC Archeticture for one the biggest system and woking much better than 
normal way.

So read this article, pass it on to your friends and rate this article

Finally: While building this project remember to build sequencially
1st: AbstractLayer
2nd: BusinessLayer
3rd: DataLayer
4th: MVC project
As these are seperate project's it self.

Troubleshooting: After doing all this next time you open MVC application you will find that
libraries are not oened by default so you need to add them under the solution as an exesting 
projects.