Using LINQ, when working with images in Web Application

Michael Livshitz

The text of this article is not in this database — only its details are. The old site it was published on is gone, but the Internet Archive kept a copy: Using LINQ, when working with images in Web Application

4 Comments

Join the conversation! Your thoughts help the community grow.

Muhammad Waqas12y ago
I love your code. Please share the full source code in a zip file I need it. Thanks in advance
miram miram16y ago
Excellent article! Thanks alot! I also very much liked the references you have made to other articles (What is an ASHX file Handler or web handler and Convert a LINQ Query Resultset to a DataTable) thats a very big help. However this article was a little to advanced to me. I would have liked you to further explain some areas, for example the ProcessImages() method and actually forward from this, just some quick commenting of the methods from ProcessImages() and forward would be a nice help. At last a link to the source code would also be greatly appreciated. Again thanks for a great article. Keep up the good work!
- Michael Livshitz16y ago
  Thanks!<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p> --------------------------------------------------------------------<o:p></o:p> //this is ProcessImages() with some comments<o:p></o:p> private void ProcessImages()<o:p></o:p> {<o:p></o:p> ImageDalDataContext dc = new ImageDalDataContext();<o:p></o:p> //we get number to recieve image; <o:p></o:p> //see line : ImageUrl='<%# "ImageHandler.ashx?biNum=" + Eval("ImageNum")%>' <o:p></o:p> //from the code for the GridViewGeneral (see below and fig. 5)<o:p></o:p> int imageNum = int.Parse(Request.Params["biNum"].ToString());<o:p></o:p> var bdi = (from i in dc.Images<o:p></o:p> where i.ImageNum.Equals(imageNum)<o:p></o:p> select i).First();<o:p></o:p> Response.Clear();<o:p></o:p> //we specify the HTTP content type for the response<o:p></o:p> Response.ContentType = bdi.ImageType.ToString();<o:p></o:p> //we write the specified information (nonstring information!) <o:p></o:p> //to the current HTTP output without any character conversion. <o:p></o:p> Response.BinaryWrite((byte[])(bdi.Img.ToArray()));<o:p></o:p> ////--------lamda-----<o:p></o:p> //ImageDalDataContext dc = new ImageDalDataContext();<o:p></o:p> //int imageNum = int.Parse(Request.Params["biNum"].ToString());<o:p></o:p> //var bdi = dc.Images.Where(i => i.ImageNum.Equals(imageNum)).First();<o:p></o:p> //Response.Clear();<o:p></o:p> //Response.ContentType = bdi.ImageType.ToString();<o:p></o:p> //Response.BinaryWrite((byte[])(bdi.Img).ToArray()); <o:p></o:p> ////------------------<o:p></o:p> }<o:p></o:p> <------------------------------------------------------------à<o:p></o:p> This is the source of the GridViewGeneral:<o:p></o:p> <o:p> </o:p> <asp:GridView ID="GridViewGeneral" runat="server" AutoGenerateColumns="False" <o:p></o:p> DataKeyNames="ImageNum" DataSourceID="ObjectDataSourceDGVGeneral" <o:p></o:p> PageSize="1"><o:p></o:p> <Columns><o:p></o:p> <asp:CommandField HeaderText="****" ShowEditButton="True" /><o:p></o:p> <asp:CommandField HeaderText="****" ShowDeleteButton="True" /><o:p></o:p> <asp:BoundField DataField="ImageNum" HeaderText="ImageNum" Visible="False" /><o:p></o:p> <asp:BoundField DataField="ForeignNum" HeaderText="ForeignNum" <o:p></o:p> Visible="False" /><o:p></o:p> <asp:TemplateField HeaderText="Name" SortExpression="ImageName"><o:p></o:p> <ItemTemplate><o:p></o:p> <asp:Label ID="Label1" runat="server" Text='<%# Bind("ImageName") %>' <o:p></o:p> Width="120px"></asp:Label><o:p></o:p> </ItemTemplate><o:p></o:p> <EditItemTemplate><o:p></o:p> <asp:TextBox ID="TextBox1" runat="server" Rows="5" <o:p></o:p> Text='<%# Bind("ImageName") %>' TextMode="MultiLine" Width="120px"></asp:TextBox><o:p></o:p> </EditItemTemplate><o:p></o:p> </asp:TemplateField><o:p></o:p> <asp:BoundField DataField="BreakType" HeaderText="ImageType" Visible="False" /><o:p></o:p> <asp:BoundField DataField="ImageSize" HeaderText="BreakImageSize" <o:p></o:p> Visible="False" /><o:p></o:p> <asp:TemplateField HeaderText="Photos"><o:p></o:p> <ItemTemplate><o:p></o:p> <asp:Image ID="Image1" runat="server" <o:p></o:p> ImageUrl='<%# "ImageHandler.ashx?biNum=" + Eval("ImageNum")%>' /><o:p></o:p> </ItemTemplate><o:p></o:p> </asp:TemplateField><o:p></o:p> <asp:BoundField DataField="LastUpdate" HeaderText="Last Update" ReadOnly="True" <o:p></o:p> SortExpression="LastUpdate" /><o:p></o:p> </Columns><o:p></o:p> </asp:GridView><o:p></o:p> <o:p> </o:p> <------------------------------------------------------------à<o:p></o:p> Good luck<o:p></o:p> <o:p> </o:p> Michael
- miram miram16y ago
  Thanks Michael Always nice to see people helping each others out :)