C# 读取数据库中 图像例子

【核心代码】

//FileName Form1.cs
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 DBImage
{
	/// <summary>
	/// Form1 的摘要说明。
	/// </summary>
	public class Form1 : System.Windows.Forms.Form
	{
		private System.Windows.Forms.ListBox listBox1;
		private System.Windows.Forms.PictureBox pictureBox1;
		private System.Windows.Forms.TextBox textBox1;
		private System.Windows.Forms.Button button1;
		private System.Windows.Forms.Button button2;
		private System.Windows.Forms.Button button3;
		/// <summary>
		/// 必需的设计器变量。
		/// </summary>
		private System.ComponentModel.Container components = null;		
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.Button button4;
		DataSet MyDataSet;
		SqlConnection MySqlConn;
		SqlDataAdapter MySqlAdapter;		
		public Form1()
		{
			//
			// Windows 窗体设计器支持所必需的
			//
			InitializeComponent();
		}
		private void ShowDBImage()
		{
			byte[] bytes=(byte[])MyDataSet.Tables[0].Rows[this.listBox1.SelectedIndex][1];
			MemoryStream memStream=new MemoryStream(bytes);
			try
			{
				Bitmap MyImage = new Bitmap(memStream);
				this.pictureBox1.Image= MyImage;
			}
			catch
			{
				MessageBox.Show(this,"读取数据库中的图像信息失败！","信息提示",MessageBoxButtons.OK,MessageBoxIcon.Information);
				this.pictureBox1.Image=null;
			}
		}

		/// <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.listBox1 = new System.Windows.Forms.ListBox();
			this.pictureBox1 = new System.Windows.Forms.PictureBox();
			this.textBox1 = new System.Windows.Forms.TextBox();
			this.button1 = new System.Windows.Forms.Button();
			this.button2 = new System.Windows.Forms.Button();
			this.button3 = new System.Windows.Forms.Button();
			this.label1 = new System.Windows.Forms.Label();
			this.button4 = new System.Windows.Forms.Button();
			this.SuspendLayout();
			// 
			// listBox1
			// 
			this.listBox1.ItemHeight = 12;
			this.listBox1.Location = new System.Drawing.Point(5, 24);
			this.listBox1.Name = "listBox1";
			this.listBox1.Size = new System.Drawing.Size(64, 76);
			this.listBox1.TabIndex = 0;
			this.listBox1.SelectedIndexChanged  = new System.EventHandler(this.listBox1_SelectedIndexChanged);
			// 
			// pictureBox1
			// 
			this.pictureBox1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
			this.pictureBox1.Location = new System.Drawing.Point(80, 16);
			this.pictureBox1.Name = "pictureBox1";
			this.pictureBox1.Size = new System.Drawing.Size(176, 80);
			this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
			this.pictureBox1.TabIndex = 1;
			this.pictureBox1.TabStop = false;
			// 
			// textBox1
			// 
			this.textBox1.Location = new System.Drawing.Point(5, 104);
			this.textBox1.Multiline = true;
			this.textBox1.Name = "textBox1";
			this.textBox1.Size = new System.Drawing.Size(352, 112);
			this.textBox1.TabIndex = 2;
			this.textBox1.Text = "textBox1";
			// 
			// button1
			// 
			this.button1.Location = new System.Drawing.Point(264, 8);
			this.button1.Name = "button1";
			this.button1.Size = new System.Drawing.Size(93, 23);
			this.button1.TabIndex = 3;
			this.button1.Text = "浏览图像";
			this.button1.Click  = new System.EventHandler(this.button1_Click);
			// 
			// button2
			// 
			this.button2.Location = new System.Drawing.Point(264, 32);
			this.button2.Name = "button2";
			this.button2.Size = new System.Drawing.Size(93, 23);
			this.button2.TabIndex = 4;
			this.button2.Text = "删除图像";
			this.button2.Click  = new System.EventHandler(this.button2_Click);
			// 
			// button3
			// 
			this.button3.Location = new System.Drawing.Point(264, 56);
			this.button3.Name = "button3";
			this.button3.Size = new System.Drawing.Size(93, 23);
			this.button3.TabIndex = 5;
			this.button3.Text = "保存图像";
			this.button3.Click  = new System.EventHandler(this.button3_Click);
			// 
			// label1
			// 
			this.label1.Location = new System.Drawing.Point(8, 8);
			this.label1.Name = "label1";
			this.label1.Size = new System.Drawing.Size(64, 16);
			this.label1.TabIndex = 6;
			this.label1.Text = "选择图像:";
			// 
			// button4
			// 
			this.button4.Location = new System.Drawing.Point(264, 80);
			this.button4.Name = "button4";
			this.button4.Size = new System.Drawing.Size(93, 23);
			this.button4.TabIndex = 7;
			this.button4.Text = "关闭程序";
			// 
			// Form1
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
			this.ClientSize = new System.Drawing.Size(360, 221);
			this.Controls.Add(this.button4);
			this.Controls.Add(this.label1);
			this.Controls.Add(this.button3);
			this.Controls.Add(this.button2);
			this.Controls.Add(this.button1);
			this.Controls.Add(this.textBox1);
			this.Controls.Add(this.pictureBox1);
			this.Controls.Add(this.listBox1);
			this.MaximizeBox = false;
			this.Name = "Form1";
			this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
			this.Text = "演示操作数据库中的图像字段";
			this.Load  = new System.EventHandler(this.Form1_Load);
			this.ResumeLayout(false);

		}
		#endregion

		/// <summary>
		/// 应用程序的主入口点。
		/// </summary>
		[STAThread]
		static void Main() 
		{
			Application.Run(new Form1());
		}

		private void Form1_Load(object sender, System.EventArgs e)
		{
			this.MySqlConn=new SqlConnection("server=COMPUTERNAME; integrated security=sspi; database=pubs");
			this.MySqlAdapter=new SqlDataAdapter("select * from pub_info","server=COMPUTERNAME; integrated security=sspi; database=pubs");

			SqlCommandBuilder MyBuilder=new SqlCommandBuilder(this.MySqlAdapter);
			this.MySqlAdapter.UpdateCommand=MyBuilder.GetUpdateCommand();
			this.MyDataSet=new DataSet();
			this.MySqlAdapter.Fill(this.MyDataSet,"pub_info");
			//将text1Box1的Text属性绑定到dataset中的pub_info表的pr_info字段
			this.textBox1.DataBindings.Add(new Binding("Text",this.MyDataSet,"pub_info.pr_info"));
			for(int i=0;i<this.MyDataSet.Tables[0].Rows.Count;i  )
			{
				this.listBox1.Items.Add(this.MyDataSet.Tables[0].Rows[i][0]);
			}
			this.listBox1.SetSelected(0,true);
		}

		private void button1_Click(object sender, System.EventArgs e)
		{//浏览图像
			OpenFileDialog MyFileDialog=new OpenFileDialog();
			MyFileDialog.ShowDialog();
			if(MyFileDialog.FileName.Trim()!="")
			{
				Stream MyStream =MyFileDialog.OpenFile();
				int length=(int)MyStream.Length;
				byte[] bytes=new byte[length];
				MyStream.Read(bytes,0,length);
				MyStream.Close();
				this.MyDataSet.Tables[0].Rows[this.listBox1.SelectedIndex][1]=bytes;
				ShowDBImage();
			}
		}
		private void button2_Click(object sender, System.EventArgs e)
		{//删除图像
			byte[] bytes =System.Text.Encoding.Unicode.GetBytes("");
			int iIndex=this.listBox1.SelectedIndex;
			this.MyDataSet.Tables[0].Rows[iIndex][1]=bytes;
			this.listBox1.SetSelected(iIndex 1,true);
			ShowDBImage();
		}
		private void button3_Click(object sender, System.EventArgs e)
		{//保存图像
			this.MySqlAdapter.Update(this.MyDataSet,"pub_info");
	        MessageBox.Show(this,"保存数据库中的图像操作成功！","信息提示",MessageBoxButtons.OK,MessageBoxIcon.Information);
		}

		private void listBox1_SelectedIndexChanged(object sender, System.EventArgs e)
		{//选择图像
			ShowDBImage();
			this.BindingContext[this.MyDataSet,"pub_info"].Position	=this.listBox1.SelectedIndex;
		}
	}
}