创建项目
1. 添加一个名为RWTest的表到 SQL Server MYTest 数据库。 表字段设置如下：
a. 唯一标识字段名称为"ID"，类型为Int。
b. 名称为"Description"的VarChar类型的字段，字段长度为50。
c. 名称为"ImgField" 的Image 类型的字段。
2. 启动 Visual Studio .NET， 并创建一个新的 Visual C# Windows 应用程序项目。
3. 从工具栏中拖两个Button 控件到默认窗体， Form1。
4. 在属性窗口中修改Name为buttonFileToDB， Text 属性为从文件保存到数据库， 然后修改Name为buttonDBToFile ，Text 属性为从数据库保存到文件。
5 从工具栏放置2个TextBox和1个PictureBox控件：Name属性分别为：textBoxGetID, textBoxGetDescription, pictureBoxGetImage, 显示从数据库读出的ID，Description，ImgField字段。
源码实例
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;
//数据库说明：MyTest数据库，RWTest表,包含3列：ID(int),Description(varchar(50),ImgField(Image)
namespace RWImgSQL
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void buttonFileToDB_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.MissingSchemaAction = MissingSchemaAction.AddWithKey;//确定现有 DataSet 架构与传入数据不匹配时需要执行的操作。
String CurrentExeName = System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName;
string ImageFile = System.IO.Path.GetDirectoryName(CurrentExeName) + "\F1.jpg";
System.IO.FileStream fileStream = new FileStream(ImageFile, FileMode.OpenOrCreate, FileAccess.ReadWrite);
byte[] myData = new byte[fileStream.Length];
fileStream.Read(myData, 0, System.Convert.ToInt32(fileStream.Length));//从流中读取字节块，并将数据写入到该缓冲区
fileStream.Close();
try
{
sqlDataAdapter.Fill(dataSet, "RWTest");
//DataRow表示DataTable中的一行数据
System.Data.DataRow dataRow;
dataRow = dataSet.Tables["RWTest"].NewRow();
dataRow1["ID"] = 1;
dataRow1["Description"] = "This would be description text";
dataRow1["ImgField"] = myData;
dataSet.Tables["RWTest"].Rows.Add(dataRow);
sqlDataAdapter.Update(dataSet, "RWTest");
sqlConnection.Close();
MessageBox.Show("写入数据库成功！", " 信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
catch (Exception ex)
{
if (sqlConnection.State == ConnectionState.Open)
{
sqlConnection.Close();
}
MessageBox.Show("写入数据库失败"+ex.Message, " 信息提示", 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");
byte[] MyData = new byte[0];
sqlDataAdapter.Fill(dataSet, "RWTest");
DataRow myRow;
myRow = dataSet.Tables["RWTest"].Rows[0];
MyData = (byte[])myRow["imgField"];
int ArraySize = MyData.GetUpperBound(0);
String CurrentExeName = System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName;
string ImageFile = System.IO.Path.GetDirectoryName(CurrentExeName) + "\F2.jpg";
FileStream fs = new FileStream(ImageFile, FileMode.OpenOrCreate, FileAccess.Write);
fs.Write(MyData, 0, ArraySize);
fs.Close();
//---在界面上的2个textBox和1个pictureBox，用来显示从数据库中读出的ID，Description，ImageField字段
textBoxGetID.Text = myRow["ID"].ToString();
textBoxGetDescription.Text = myRow["Description"].ToString();
pictureBoxGetImage.Image = Image.FromFile(ImageFile);
if (sqlConnection.State == ConnectionState.Open)
{
sqlConnection.Close();
}
MessageBox.Show(" 从数据库读出数据成功！", " 信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
}
}