有时我们需要把一些大的数据对象如图片、可执行文件、视频和文档等数据存入数据库。在MS SQL Server中，这要用到Image数据类型，可以保存多达2G的数据。以下给出一个通过ADO.NET和MS SQL Server实现的小小的例子。 先创建一个测试数据表。在查询分析器中输入并执行以下语句：Create table [imgtable]( [imgid] [int] IDENTITY(1,1) NOT NULL, [imgname] [varchar](100) COLLATE Chinese_PRC_CI_AS NULL, [imgData] [image] NULL, PRIMARY KEY CLUSTERED ( [imgid] ) ON [PRIMARY]) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY] 这要在你所选的数据库中就多了一个名叫imgtable的表。 VS中的代码如下：using System;using System.Drawing;using System.Collections;using System.ComponentModel;using System.Windows.Forms;using System.Data;using System.Data.SqlClient;using System.IO; namespace ADO_Demo{ /// <summary> /// Form1 的摘要说明。 /// </summary> public class ADO_Demo : System.Windows.Forms.Form {  private System.Windows.Forms.Button button1;  private System.Windows.Forms.Button button2;  private System.Windows.Forms.PictureBox pictureBox1;  private System.Windows.Forms.OpenFileDialog openFileDialog1;  private System.Windows.Forms.Button button3;  /// <summary>  /// 必需的设计器变量。  /// </summary>  private System.ComponentModel.Container components = null;   public ADO_Demo()  {   //   // Windows 窗体设计器支持所必需的   //   InitializeComponent();    //   // TODO: 在 InitializeComponent 调用后添加任何构造函数代码   //  }   /// <summary>  /// 清理所有正在使用的资源。  /// </summary>  protected override void Dispose( bool disposing )  {   if( disposing )   {    if (components != null)     {     components.Dispose();    }   }   base.Dispose( disposing );  }   #region Windows 窗体设计器生成的代码  /// <summary>  /// 设计器支持所需的方法 - 不要使用代码编辑器修改  /// 此方法的内容。  /// </summary>  private void InitializeComponent()  {   this.button1 = new System.Windows.Forms.Button();   this.button2 = new System.Windows.Forms.Button();   this.pictureBox1 = new System.Windows.Forms.PictureBox();   this.openFileDialog1 = new System.Windows.Forms.OpenFileDialog();   this.button3 = new System.Windows.Forms.Button();   this.SuspendLayout();   //    // button1   //    this.button1.Location = new System.Drawing.Point(368, 48);   this.button1.Name = "button1";   this.button1.Size = new System.Drawing.Size(104, 23);   this.button1.TabIndex = 0;   this.button1.Text = "保存图片";   this.button1.Click += new System.EventHandler(this.button1_Click);   //    // button2   //    this.button2.Location = new System.Drawing.Point(368, 120);   this.button2.Name = "button2";   this.button2.Size = new System.Drawing.Size(104, 23);   this.button2.TabIndex = 1;   this.button2.Text = "显示图片";   this.button2.Click += new System.EventHandler(this.button2_Click);   //    // pictureBox1   //    this.pictureBox1.Location = new System.Drawing.Point(8, 16);   this.pictureBox1.Name = "pictureBox1";   this.pictureBox1.Size = new System.Drawing.Size(312, 288);   this.pictureBox1.TabIndex = 2;   this.pictureBox1.TabStop = false;   //    // openFileDialog1   //    this.openFileDialog1.FileOk += new System.ComponentModel.CancelEventHandler(this.openFileDialog1_FileOk);   //    // button3   //    this.button3.Location = new System.Drawing.Point(368, 200);   this.button3.Name = "button3";   this.button3.Size = new System.Drawing.Size(104, 23);   this.button3.TabIndex = 1;   this.button3.Text = "读取文件并打开";   this.button3.Click += new System.EventHandler(this.button3_Click);   //    // ADO_Demo   //    this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);   this.ClientSize = new System.Drawing.Size(496, 317);   this.Controls.Add(this.pictureBox1);   this.Controls.Add(this.button2);   this.Controls.Add(this.button1);   this.Controls.Add(this.button3);   this.Name = "ADO_Demo";   this.Text = "ADO_Demo";   this.ResumeLayout(false);   }  #endregion   /// <summary>  /// 应用程序的主入口点。  /// </summary>  [STAThread]  static void Main()   {   Application.Run(new ADO_Demo());  }   /// <summary>  /// 点击打开文件对话框确定按钮，将文件保存到数据库中  /// </summary>  /// <param name="sender"></param>  /// <param name="e"></param>  private void openFileDialog1_FileOk(object sender, System.ComponentModel.CancelEventArgs e)  {   string filename = this.openFileDialog1.FileName;   SqlConnection conn = new SqlConnection("server=192.168.2.200;integrated security = sspi;database = northwind");   SqlCommand cmd = new SqlCommand("insert imgtable values(@imgname,@imgData)",conn);   SqlParameter pm = new SqlParameter("@imgname",SqlDbType.VarChar,100);   pm.Value = filename;   SqlParameter pm1 = new SqlParameter("@imgData",SqlDbType.Image);   FileStream fs = new FileStream(filename,FileMode.Open);   int len = (int)fs.Length;   byte[] fileData = new byte[len];   fs.Read(fileData,0,len);   fs.Close();    pm1.Value = fileData;   cmd.Parameters.Add(pm);   cmd.Parameters.Add(pm1);    conn.Open();   try   {    cmd.ExecuteNonQuery();   }   catch(Exception ex)   {    MessageBox.Show(ex.Message);   }   }   private void button1_Click(object sender, System.EventArgs e)  {   this.openFileDialog1.ShowDialog();  }   /// <summary>  /// 从数据库中读取bitmap图片并显示  /// </summary>  /// <param name="sender"></param>  /// <param name="e"></param>  private void button2_Click(object sender, System.EventArgs e)  {   SqlConnection conn = new SqlConnection("server=192.168.2.200;integrated security = sspi;database = northwind");   SqlCommand cmd = new SqlCommand("select * from imgtable where imgname like '%bmp%'",conn);   conn.Open();   SqlDataReader dr;   try   {    dr = cmd.ExecuteReader();    dr.Read();    System.Data.SqlTypes.SqlBinary sb = dr.GetSqlBinary(2);    //或byte[] imageData = (byte[])dr[2];    MemoryStream ms = new MemoryStream(sb.Value);//在内存中操作图片数据    Bitmap bmp = new Bitmap(Bitmap.FromStream(ms));    this.pictureBox1.Image = bmp;    dr.Close();   }   catch(Exception ex)   {    MessageBox.Show(ex.Message);   }   finally   {    conn.Close();   }  }   /// <summary>  /// 读取文件并保存到硬盘，然后打开文件  /// </summary>  /// <param name="sender"></param>  /// <param name="e"></param>  private void button3_Click(object sender, System.EventArgs e)  {   SqlConnection conn = new SqlConnection("server=192.168.2.200;integrated security = sspi;database = northwind");   SqlCommand cmd = new SqlCommand("select * from imgtable where imgname like '%doc'",conn);   conn.Open();   SqlDataReader dr;   try   {    dr = cmd.ExecuteReader();    dr.Read();    System.Data.SqlTypes.SqlBinary sb = dr.GetSqlBinary(2);    //或byte[] imageData = (byte[])dr[2];    //FileStream fs = new FileStream(@"C:\temp.bmp",FileMode.Create);    string filename = @"C:\" + System.IO.Path.GetFileName(dr.GetString(1));    FileStream fs = new FileStream(filename,FileMode.Create);    fs.Write(sb.Value,0,sb.Value.Length);    fs.Close();    //this.pictureBox1.Image = Image.FromFile(@"C:\temp.bmp");    System.Diagnostics.Process.Start(filename);    dr.Close();   }   catch(Exception ex)   {    MessageBox.Show(ex.Message);   }   finally   {    conn.Close();   }  } }} 直接把整个文件读取到内存中的数组里对于小文件来说是没问题的，但如果是大文件，特别是大小都超过了物理内存的文件，可能会导致严重的内存问题，需要分段读取，并分段写到数据库。

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