How to resolve " System.ArgumentException: Value cannot be null or empty. Parameter name: contentPath" this error? - asp.net-mvc

Question

The following is my updateproduct.cshtml file where i am getting an error.
#model ShopperDB.Context.Product
#using (Html.BeginForm())
{
#Html.AntiForgeryToken()
<div class="form-horizontal">
<h2 class="admin-title text-center">Edit Product</h2>
<hr />
#Html.ValidationSummary(true, "", new { #class = "text-danger" })
#Html.HiddenFor(model => model.ProductID)
<div class="form-group">
#Html.LabelFor(model => model.ProductName, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-6">
#Html.EditorFor(model => model.ProductName, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.ProductName, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.ProductImage, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-6">
<img src="#Url.Content(Model.ProductImage)" alt="IMAGES" height="300" ; width="300" />
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.Description, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-6">
#Html.EditorFor(model => model.Description, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.Description, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.Price, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-6">
#Html.EditorFor(model => model.Price, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.Price, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.CategoryID, "CategoryName", htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-6">
#Html.DropDownList("CategoryID", null, htmlAttributes: new { #class = "form-control" })
#Html.ValidationMessageFor(model => model.CategoryID, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Save" class="btn btn-default" />
</div>
</div>
</div>
}
</div>
</div>
</div>
</div>
}
The following is my update product method from product controller.
//Update the product
[HttpGet]
[Route("product/update/{id}")]
[CustomAuthorize("admin")]
public ActionResult UpdateTheProduct(int? id)
{
if (Session["UserName"].ToString() != null)
{
if (Session["UserName"].ToString() == "admin")
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
Product product = db.Products.Find(id);
if (product == null)
{
return HttpNotFound();
}
ViewBag.CategoryID = new SelectList(db.ProductCategories, "CategoryID", "CategoryName");
return View(product);
}
else
{
return RedirectToAction("Index", "Home");
}
}
else
{
return RedirectToAction("Index", "Home");
}
}
[HttpPost]
[ValidateAntiForgeryToken]
[Route("product/update/{id}")]
[CustomAuthorize("admin")]
public ActionResult UpdateTheProduct([Bind(Include = "ProductID,ProductName,ProductImage,Description,Price,CategoryID")] Product product)
{
if (ModelState.IsValid)
{
if (db.Products.Any(ac => ac.ProductName.Equals(product.ProductName)))
{
TempData["fail"] = "Category already Added";
}
else
{
TempData["notice"] = "Successfully Added";
db.Entry(product).State = EntityState.Modified;
db.SaveChanges();
}
return RedirectToAction("ListOfProducts");
}
return View(product);
}
while i am updating the product it is showing me System.ArgumentException: Value cannot be null or empty.Parameter name: contentPath this error on storing ProductImage point.
So please kindly help me to resolve this error.

Answer 1

This part of code in your view potentially throwing contentPath exception:
<img src="#Url.Content(Model.ProductImage)" alt="IMAGES" height="300" ; width="300" />
If Model.ProductImage value is null or empty instead of containing a relative path string when passed to view, it will throw contentPath exception since Url.Content method cannot have null or empty argument.
To solve content URL issue, put if-condition check against null or empty value on ProductImage property in UpdateTheProduct (either GET or POST action method, or both of them) and set its default value using relative path:
if (String.IsNullOrEmpty(Model.ProductImage))
{
Model.ProductImage = "~/path/imagefile";
}
// some code
return View(product);
Related issues:
Value cannot be null or empty. Parameter name: contentPath
"Value cannot be null or empty. Parameter name: contentPath" on a most unexpected line on postback when ModelState has errors