What's the best way to show a random image in

问题:

What I am talking about is like this website : http://www.ernesthemingwaycollection.com

It has a static wallpaper and a set of images that change from page to page, I want to implement a similar way of displaying random images from a set of images using ASP.NET.

EDIT : I want the image to stay the same in a session, and change from a session to another.

回答1:

The site you mentioned is not using a random set of images. They are coded into the html side of the aspx page.

You could place an asp Image control on your page. Then on the page's Page_Load function set the image to a random picture of your set.

protected void Page_Load(object sender, EventArgs e)
        {

            this.Image1.ImageUrl = "~/images/random3.jpg";
        }

You have different options on where to store the image set data. You could use a database and store the urls in a table. This would allow to use the built-in Random function found in SQL. Or you can save a XML file to the server, load that then use the Random .Net class to pick one of your xml nodes.

Personally i would recommend the Database solution.

EDIT: Because the server session is destroyed after 20mins you may want to look at using cookies so you can see the last random image they saw.

回答2:

If you just want to rotate a set number of images you could use the ASP.NET AdRotator control (at last, a use for it!).

If you want to do something fancier, considering using a jQuery slideshow such jQuery Cycle Plugin. There is also a slideshow control in the AjaxControlToolkit, which is easy to integrate.

回答3:

string imageDir = "/images/banner/";

public static string chooseImage(string imageDir)
        {
            string[] dirs = Directory.GetFiles(HttpContext.Current.Server.MapPath("~/images/" + imageDir + "/"), "*.*");
            Random RandString = new Random();

            string fileFullPath = dirs[RandString.Next(0, dirs.Length)];

            // Do not show Thumbs.db --- 
            string fileName = string.Empty;
            do
            {
                fileName = System.IO.Path.GetFileName(fileFullPath);

            } while (fileName.Contains(".db"));


            string imgPath = "/images/" + imageDir + "/" + fileName;
            return imgPath;
        }

        private int RandomNumber(int min, int max)
        {
            Random random = new Random();
            return random.Next(min, max);
        }