showimagecs.aspx.cs

Telerik是很大的第三方软件制造商

using System;
using System.Data.OleDb;
using System.Drawing;
using System.IO;

namespace Telerik.UploadExamplesCSharp.PhotoGallery
{
	public class ShowImageCS : System.Web.UI.Page
	{
		private void Page_Load(object sender, System.EventArgs e)
		{
			//Get the file information from the database
			OleDbConnection conn = new OleDbConnection(DefaultCS.GetConnectionString(Request));
			conn.Open();
			if(Request.QueryString["imgid"] == null)
			{
				WriteImage(GetEmptyImage(), "NoImage");
				return;
			}

			string query = "SELECT {0}, [Name] FROM Images WHERE ImageID = ?";

			//Check if to get the thumbnail of a file, or to get the full file
			if((Request.QueryString["type"] != null) && (Request.QueryString["type"] == "thumb"))
			{
				query = String.Format(query, "Thumbnail");
			}
			else
			{
				query = String.Format(query, "[Image]");
			}

			//Get the image and display it
			OleDbCommand command = new OleDbCommand(query, conn);
			command.Parameters.Add("@ImageID", int.Parse(Request.QueryString["imgid"]));
			using (OleDbDataReader reader = command.ExecuteReader())
			{
				if(reader.Read())
				{
					WriteImage((byte[])reader[0], reader[1].ToString());
				}
				else
				{
					//There was not such an image, so display the no_image image
					WriteImage(GetEmptyImage(), "NoImage");
				}
			}
		}

		private void WriteImage(byte[] image, string fileName)
		{
			Response.Buffer = true;
			Response.Clear();
			Response.ContentType = "image/gif";
			Response.AddHeader("content-disposition", "inline; filename=" + fileName);
			Response.BinaryWrite(image);
			Response.Flush();
			Response.End();
		}

		private byte[] GetEmptyImage()
		{
			int height = DefaultCS.MAX_THUMBNAIL_HEIGHT;
			int width = DefaultCS.MAX_THUMBNAIL_WIDTH;
			Bitmap empty = new Bitmap(width, height);
			MemoryStream ms = new MemoryStream();
			empty.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
			return ms.ToArray();
		}

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			InitializeComponent();
			base.OnInit(e);
		}
		
		private void InitializeComponent()
		{    
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion
	}
}