C # Access SQL Server database two: Using serialization for class linked list access (Arraylist,varbina

Create a project

1. Add a table named rwtest to the SQL Server MYTest database. The table field is set as follows:

A. uniquely identifies the field name is "ID"and the type is Int.

B. a field of type VarChar called "Description" with a field length of

c. A field of type varbinary (Max) called "Data" .

2. start visual Studio. NET and create a new Visual C # Window S Application project.

3. Drag two Button controls from the toolbar to the default form, Form1 .

4. in the Properties window, modify Name buttonfiletodb, Text property is saved to the database from the file, and then the Name is modified to buttondbtofile , the Text property is saved to a file from the database .

SOURCE Example

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Data.SqlClient;

using System.IO;

using System.Collections;

using System.Runtime.Serialization.Formatters.Binary;

// Database Description: MyTest database, rwtest Table , contains 3 columns: ID (int), Description (varchar), Data (varbinary (max))

namespace Rwarraylistsql

{

public partial class Form1 : Form

    {

ArrayList ArrayList = new ArrayList();

public Form1 ()

        {

InitializeComponent ();

for (int i = 0; i < i++)

            {

ptdata ptdata = new ptdata();

Ptdata.ptid = i + 1;

ptdata.ptname = Convert. ToString (i + 1);

Ptdata.pt_data = i + 1;

Arraylist.add (ptdata);

            }

        }

private void Buttonfiletodb_click (object sender, EventArgs E

        {

SqlConnection SqlConnection = new SqlConnection("Data Source=liuxu Eqin;initial catalog=mytest;integrated security=true ");                

SqlDataAdapter sqldataadapter = New SqlDataAdapter ( "SELECT * from Rwtest", SqlConnection);

sqlcommandbuilder sqlcommandbuilder = new SqlCommandBuilder(Sqldataada Pter);

System.Data. DataSet DataSet = new DataSet("rwtest");

sqldataadapter.missingschemaaction = MissingSchemaAction. AddWithKey; // Identify existing DataSet the action to perform if the schema does not match the incoming data.

                // Define a stream

Stream stream = new MemoryStream();

                // Define a formatter

binaryformatter bf = new BinaryFormatter();

foreach (object obj in arrayList)

                {

BF. Serialize (stream, obj); // serialization

                }

byte[] array = null;

array = new byte[stream. Length];

                // to write a binary stream to an array

Stream. Position = 0;

Stream. Read (array, 0, (int) stream. Length);

                // Close the stream

Stream. Close ();

try

            {

Sqldataadapter.fill (DataSet, "Rwtest");

//datarow represents a row of data in a DataTable

System.Data. DataRow DataRow1;

dataRow1 = dataset.tables["Rwtest"]. NewRow ();

datarow1["ID"] = 1;

datarow1["Description"] = "This would is Description text";                

datarow1["Data"] = array;

dataset.tables["Rwtest"]. Rows.Add (DATAROW1);

sqldataadapter.update (DataSet, "Rwtest");

sqlconnection.close ();

MessageBox. Show (" write to database success!") ", " Information tips , messageboxbuttons. OK, MessageBoxIcon. Information);

            }

Catch (Exception ex)

            {

If (sqlconnection.state = = ConnectionState. Open)

                {

sqlconnection.close ();

                }

MessageBox. Show ( Write database failed )+ex. Message, " informational hint ", messageboxbuttons. OK, MessageBoxIcon. ERROR);

            }

        }

private void Buttondbtofile_click (object sender, EventArgs E

        {

SqlConnection SqlConnection = new SqlConnection("Data Source=liuxueqin ; Initial catalog=mytest;integrated security=true ");

SqlDataAdapter SqlDataAdapter = new SqlDataAdapter("SELECT * From Rwtest ", SqlConnection);

sqlcommandbuilder sqlcommandbuilder = new SqlCommandBuilder(SqlDataAdapter );

DataSet DataSet = new DataSet("rwtest");

Sqldataadapter.fill (DataSet, "Rwtest");

DataRow myrow;

myrow = dataset.tables["Rwtest"]. Rows[0];

byte [] b = null;

B = (byte[]) myrow["Data"];

            // Define a stream

MemoryStream stream = new MemoryStream(b);

            // Define a formatter

binaryformatter bf = new BinaryFormatter();            

while (stream. Position!= Stream. Length)

            {

Arraylist.add (BF. Deserialize (stream)); // deserialization

            }

Stream. Close ();

for (int i=0;i<5;i++) // Informational prompt, is the correct removal of the ARRA from the database Ylist Linked list

MessageBox. Show (((ptdata) arraylist[i]). Ptname, " Information tips ", messageboxbuttons. OK, MessageBoxIcon. Information);

If (sqlconnection.state = = ConnectionState. Open)

            {

sqlconnection.close ();

            }

MessageBox. Show (" read data from database success!") ", " Information tips , messageboxbuttons. OK, MessageBoxIcon. Information);

        }

}

// added attributes on top of class: Serializable. ( If you do not add this property , will throw SerializationException Exception ). Without inheriting from the interface ISerializable , you can allow the class to be serialized by adding the [Serializable] property.

[Serializable]

class ptdata

    {

public ptdata ()

        {

Ptid = 1;

ptname = "None";

Pt_data = 1.0;

        }

public int Ptid;

public string ptname;

public double Pt_data;

    }

}

</