WCF learning journey-Example 3 () and Example 3

WCF learning journey-Example 3 () and Example 3
I. Preface

Based on the previous 20 chapters, we know what it is: WCF; A, B, and C in WCF; the transfer mode of WCF; the boarding mode of WCF; and Exception Handling of WCF. This article combines the above knowledge points and writes a small WCF application-BookMgr ).

This example is a very simple book management system with functions such as query, modification, addition and deletion (excluding security and optimization issues) and exception handling. Addition, deletion, modification, and query of WCF are almost the same as that of WinForm. WCF only writes the specific "Implementation" in "server", while "call" is placed in "client ".

Ii. BookMgr description

1) The "server" of the Demo takes the local console application as the host, and the "client" takes the WinForm project as an example.

2) Demo's "server" extracts data using a layered structure that is more acceptable to beginners, which can be divided into the service layer, entity layer, and data layer.

Shows the reference relationship:

3) the Demo database is SqlServer and the table is Books (the SQL statement is "initialization script. SQL" in the downloaded Package). The table structure is as follows:

Field name	Column name	Data Type	Constraints	Generation Method
Book No.	BookID	Int	Primary Key, required	Auto-Increment
Title	Name	Nvarchar (200)	Required	Manual Input
Category	Category	Nvarchar (50)	Required	Manual Input
Number of publications	Numberofcopies	Int	Required	Manual Input
Author ID	AuthorID	Int	Required	Manual Input
Price	Price	Decimal (18,2)	Required	Manual Input
Publication date	PublishDate	Datetime	Required	Manual Input
Rating	Rating	Nvarchar (5)	Not Required	Manual Input

3. Create a WCF server project structure

• BookMgr. Contracts:A class library project that defines Service Contract and references the System. ServiceMode assembly. See.

 BookMgr. Services:A class library project that provides the implementation of the WCF Service. Define all the WCF Services in this project to implement the corresponding service agreements defined in Contracts, so Services have references to the Contracts project. See Figure 1, Figure 2.

 

Figure 1

Figure 2

• BookMgr. Hosting:A Console application is used to host Services defined in the Services Project. This project must reference both the Contracts and Services projects and the System. ServiceMode assembly. See Figure 1, Figure 2.

Figure 1

Figure 2

• BookMgr. Common: Public classes in the solution. See.

 BookMgr. Model:An object project is used to construct an object for the table structure in the database. It is implemented through EF 6. See.

• The final project structure is as follows.

4. Create a BookMgr. Contracts project code

1Create an IBookService interface file and a SQLError file in the project. See.

2) create a class SQLError. cs that indicates a Fault exception in BookMgr. Contracts. The Code is as follows.

using System;using System.Collections.Generic;using System.Linq;using System.Runtime.Serialization;using System.Text;using System.Threading.Tasks; namespace BookMgr.Contracts{    [DataContract]    public class SQLError    {        private string _operation;        private string _errorMessage;        public SQLError(string operation, string errorMessage)        {            this._operation = operation;            this._errorMessage = errorMessage;        }        [DataMember]        public string Operation        {            get { return _operation; }            set { _operation = value; }        }         [DataMember]        public string ErrorMessage        {            get { return _errorMessage; }            set { _errorMessage = value; }        }    }}

 

3) IBookService. cs interface file in BookMgr. Contracts. Create Add, Delete, modify, query, Add, Edit, Delete, Get, and Search methods respectively, the five functions correspond to the service application WCF Service Application respectively. I added a feature for returning custom exceptions in the "Edit" method. The Code is as follows.

 

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace BookMgr.Contracts{    public interface IBookService{  [OperationContract]         string Add(string bookInfo);  [OperationContract]        [FaultContract(typeof(SQLError))]        string Edit(string bookInfo);  [OperationContract]        string Get(string bookId);  [OperationContract]         string Delete(string bookInfo);  [OperationContract]        string Search(string Category, string searchString);     }}