The list of items the dropdown will be displaying. Note that this isn’t just a string - we’re passing a list of Genres.

The next parameter being passed to the SelectList is the Selected Value. This how the SelectList knows how to pre-select an item in the list. This will be easier to understand when we look at the Edit form, which is pretty similar.

/** above line must be wrong ! in the edit action code, there are 4 parameters,

ViewBag.GenreId = new SelectList(db.Genres, "GenreId", "Name", album.GenreId);

the last parameter is the selected value, let the DropDownList know how to pre-select item. **/

The final parameter is the property to be displayed. In this case, this is indicating that the Genre.Name property is what will be shown to the user.

Thanks

We will need to start by creating a custom partial view that will live in “~/Views/Shared/DisplayTemplates/UserGuid.cshtml”, and “~/Views/Shared/EditTemplates/UserGuid.cshtml”. The code for one is located below:

@model Guid

@{

incMvcSite.Models.MvcSiteDB db = new incMvcSite.Models.MvcSiteDB();

incMvcSite.Models.SecUser usr = db.SecUsers.Single(u => u.Guid == Model);

}

@usr.Display

This is a display for template that will look up the item in the referenced table and display it. We also need an edit for template as follows:

@model Guid

@{

incMvcSite.Models.MvcSiteDB db = new incMvcSite.Models.MvcSiteDB();

SelectList items = new SelectList(db.SecUsers.OrderBy(i => i.Display).ToList(), "Guid", "Display", Model);

}

@Html.DropDownList("", items)

The edit for template is implemented as a drop down list. Originally, we has used static HTML code, but the problem will appear of implementing a “prefix”. Static HTML code does get handled by HTML helpers, so it’s recommended that you use the HTML.DropDownList().

To force the MVC framework to use the new Display and Edit for templates, we need to annote our model item an add the following line:

[UIHint("UserGuid")]

This will cause MVC to use the Display and Edit templates named “UserGuid”, which are just partial views.

www.internetworkconsulting.net

Mohammad

<HttpPost()>

Function Edit(album As Album) As ActionResult

If ModelState.IsValid Then

_db.Entry(Album).State = EntityState.Modified

_db.SaveChanges()

Return RedirectToAction("Index")

End If

ViewBag.GenreId = New SelectList(_db.Genres, "GenreId", "Name", Album.GenreId)

ViewBag.ArtistId = New SelectList(_db.Artists, "ArtistId", "Name", Album.ArtistId)

Return View(Album)

End Function

ms_gigabyte : On November 25, 2011 06:52 AM said:

ms_gigabyte : I am getting Store update, insert, or delete statement affected an unexpected number of rows (0).

You can fix this by adding the following line to the Edit.cshtml file

@Html.HiddenFor(model => model.AlbumId)

The reason for that error is the AlbumId is not posted back, so it defaults to zero (and there is 0 AlbumId in the DB).

Null value for non-nullable member. Member: 'Artist'.

It hangs on this line of code:

db.SaveChanges();

Microsoft JScript runtime error: 'jQuery' is undefined.

Note other functions are ok, Delete, Details

Unable to retrieve metadata for MvcMusicStore.Models.Album. Could not load file or assembly, file///C:Users\XXXX\AppData\Local\Temp\rpnn41bq.dll' or one of its dependencies. Operation is not supported. (Exception from HRESUL: 0x80131515

Any idea? many thanks!

I found this;

[Bind(Exclude = "AlbumId")]

in the Album.cs file and if I comment this out the edit works. It's not real clear why this is there however.

There is also a line that says;

[ScaffoldColumn(false)]

Would this prevent the generated view from getting a line for the AlbumId?

You need to add this to the View file. Especially for Create and Edit StoreManager.

<script src="ajax.aspnetcdn.com/" type="text/javascript"></script>

This is an error. At that time, MusicStoreEntities does not have Artists property.