Server.MapPath throws error when using web image cropping library

I have an image stored on server at location:

C:\inetpub\wwwroot\imageupload\images

in my code i want to use an image from folder images so i am trying as follows:

Server.MapPath("/images/sample1.jpg")

But i am getting the error as: enter image description here

Please help me to solve the error

As on several answer asking to post the code,it is as follows

.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

<%@ Register Assembly="CS.Web.UI.CropImage" Namespace="CS.Web.UI" TagPrefix="cs" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
 <cs:CropImage ID="wci1" runat="server" />
    </body>
</html>

.aspx.cs

using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Default2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

        wci1.Crop(Server.MapPath("/imageupload/images/sample1.jpg"));

        /*
         this part is just to show the image after its been cropped and saved! so focus on just the code above.
         */
        Image img = new Image();
        img.ImageUrl = "images/sample1.jpg?rnd=" + (new Random()).Next();  // added random for caching issue.
        this.Controls.Add(img);
    }
}

Crop method is from a .dll file i have used from http://imagecropping.codeplex.com/

Solution

There error is in the CSA.Web.UI.CropImage.Crop method, as described by the stack trace.

Server.MapPath, to my knowledge, will not return a null string (it'll throw an exception if it can't map - but not a NullReferenceException).

I'd suggest you look into the method I mention and possibly post the relevant code, too.

EDIT:

So, I had a quick look at the Crop code from the CodePlex project you mention and found the following lines (formatting mine):

private string ImagePath { get { return ViewState["ImageUrl"].ToString(); } }

drawing.Image image = drawing.Image.FromStream(
    new MemoryStream(
        System.IO.File.ReadAllBytes(
            HttpContext.Current.Server.MapPath(this.ImagePath)
        )
    )
);

cropedImage.Save(path);

Now, it seems to me that:

Argument Path is not null*
Argument ImageUrl is null**

*Though it might be 'incorrect' it isn't the problem right now.

**Meaning the call ToString is the breaking factor in this code.

Basically, the control doesn't have an image set to crop and this is evident in your own code:

//currently no ImageUrl set...
<cs:CropImage ID="wci1" runat="server" />

//your'e trying to crop here without an ImageUrl...
wci1.Crop(Server.MapPath("/imageupload/images/sample1.jpg"));

The fix is to specify an image via ImageUrl, AFAIK, however I can't see how to do so.