Chapter 14 Pg514-517

hansheung · November 21st, 2016, 01:53 PM

Hi can anyone please help with the following error. I entered the ManagePhotoAlbum.aspx.vb code accordingly but I keep getting the following error. I am not sure where or what I have done wrong to get this error. Please help.

At the bold and underline of the following code.
There is this error stating: 'Pictures' is not a member of 'System.Array'.

The Code:

Code:

Imports System.Web.ModelBinding

Partial Class _ManagePhotoAlbum
    Inherits BasePage

    Public Function ListView1_GetData(<QueryString("PhotoAlbumId")> photoAlbumId As Integer) As IQueryable
        Dim myEntities As PlanetWroxEntities()
        Return From p In myEntities.Pictures
               Where p.PhotoAlbumId = photoAlbumId
               Select p
    End Function

    Public Sub ListView1_InsertItem(<QueryString("PhotoAlbumId")> photoAlbumId As Integer)
        Dim picture As New Picture()
        TryUpdateModel(picture)
        If ModelState.IsValid Then
            Using myEntities As New PlanetWroxEntities()
                picture.PhotoAlbumId = photoAlbumId
                myEntities.Pictures.Add(picture)
                myEntities.SaveChanges()
            End Using
        End If
    End Sub

    ' The id parameter name should match the DataKeyNames value set on the control
    Public Sub ListView1_DeleteItem(ByVal id As Integer)

    End Sub
End Class

Picture.vb

Imar · November 22nd, 2016, 05:39 AM

Hi there,

You're missing the New keyword when defining the PlanetWroxEntities. Without New, the () means you're declaring an array of PlanetWroxEntities, not instantiating a new instance of PlanetWroxEntities. Your code should look as follows:

Dim myEntities As New PlanetWroxEntities()

Hope this helps,

Imar

hansheung · November 22nd, 2016, 06:28 AM

Hi Imar, again, thank you so much for your quick reply.
After correcting the New instances. I still run into error. I get the following error. Please help.

Expression of type 'Object' is not queryable. Make sure you are not missing an assembly reference and/or namespace import for the LINQ provider.

The code

Code:

Imports System.Web.ModelBinding

Partial Class _ManagePhotoAlbum
    Inherits BasePage

    Public Function ListView1_GetData(<QueryString("PhotoAlbumId")> photoAlbumId As Integer) As IQueryable
        Dim myEntities As New PlanetWroxEntities()
        Return From p In myEntities.Pictures
               Where p.PhotoAlbumId = photoAlbumId
               Select p
    End Function

    Public Sub ListView1_InsertItem(<QueryString("PhotoAlbumId")> photoAlbumId As Integer)
        Dim picture As New Picture()
        TryUpdateModel(picture)
        If ModelState.IsValid Then
            Using myEntities As New PlanetWroxEntities()
                picture.PhotoAlbumId = photoAlbumId
                myEntities.Pictures.Add(picture)
                myEntities.SaveChanges()
            End Using
        End If
    End Sub

    ' The id parameter name should match the DataKeyNames value set on the control
    Public Sub ListView1_DeleteItem(ByVal id As Integer)

    End Sub
End Class

Imar · November 22nd, 2016, 09:06 AM

Your code looks fine now, so maybe something is wrong with your PlanetWroxEntities? Is that correctly referring to your EF Model? What do you get when you click on PlanetWroxEntities and then press F12 (Go to definition)?

Imar

hansheung · November 22nd, 2016, 10:50 AM

I get the following code:

Code:

Imports System
Imports System.Data.Entity
Imports System.Data.Entity.Infrastructure

Partial Public Class PlanetWroxEntities
    Inherits DbContext

    Public Sub New()
        MyBase.New("name=PlanetWroxEntities")
    End Sub

    Protected Overrides Sub OnModelCreating(modelBuilder As DbModelBuilder)
        Throw New UnintentionalCodeFirstException()
    End Sub

    Public Property Genres() As DbSet(Of Genre)
    Public Property Reviews() As DbSet(Of Review)

    Function PhotoAlbums() As Object
        Throw New NotImplementedException
    End Function

    Function Pictures() As Object
        Throw New NotImplementedException
    End Function

End Class

Imar · November 22nd, 2016, 11:05 AM

Looks like you incorrectly added the Picture and PhotoAlbum entities. Note how they are defined as a Function. They should be properties similar to how Genres and Reviews are done. I.e.:

Code:

Public Property PhotoAlbums) As DbSet(Of PhotoAlbum)

Try recreating the EF model and see if that fixes it.

Imar

hansheung · November 23rd, 2016, 09:35 AM

Hi Imar, thanks again. By recreating the EF model. I have managed to get the 2 entries generated. Hence get rid of all the PhotoAlbum and Picture is not an entity of PlanetWroxEntities errors.
Public Overridable Property PhotoAlbums() As DbSet(Of PhotoAlbum)
Public Overridable Property Pictures() As DbSet(Of Picture)

However, when I run the NewPhotoAlbum.aspx, entered an entry and clicked Insert. I encounter another error at MyBase.New("name=PlanetWroxEntities"). The error is attached at the following link.

The error:
The type initializer for 'System.Data.Entity.Internal.AppConfig' threw an exception.

Please help.
https://s13.postimg.org/gugl5cpev/Sc...v_23_21_29.jpg

The error code on the page
Configuration Error

Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: An error occurred creating the configuration section handler for entityFramework: Could not load file or assembly 'EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Source Error:

Line 7: <configSections>
Line 8: 
Line 9: <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.Entit yFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
Line 10: </configSections>

Imar · November 24th, 2016, 05:12 AM

Hi there,

Looks like you're mixing EF5 and EF6. You may have to fully uninstall them (including cleaning up web.config) and then install one or the other. Take a look at these threads for more info:

the book and problem with EF
Chapter 14, first try it out - Compilation Error Planet Wrox - Entity Framework

Cheers,

Imar

hansheung · November 30th, 2016, 04:19 AM

Solved, thanks Imar.

I managed to solve my errors by going to Website -> Manage NuGet. Choose Entity Framework version 6.x.x. Update or install it. Load NewPhotoAlbum, key in an entry and everything works. Thanks Imar.

hansheung · November 30th, 2016, 04:33 AM

Dear Imar, another error pop up when I try to insert the description, Tooltips and ImageUrl. Please help, I don't know where to start debugging.

https://s12.postimg.org/s4vycanmh/Sc...v_30_16_31.jpg

System.Web.HttpException was unhandled by user code
ErrorCode=-2147467259
HResult=-2147467259
Message=DataBinding: 'System.Data.Entity.DynamicProxies.Picture_E8A62F0 EC52366028B3F9AAA43609A3BF087C764352C7F4411F4BCC2C 4F487E9' does not contain a property with the name 'Description'.
Source=System.Web
WebEventCode=0
StackTrace:
at System.Web.UI.DataBinder.GetPropertyValue(Object container, String propName)
at System.Web.UI.DataBinder.Eval(Object container, String[] expressionParts)
at System.Web.UI.DataBinder.Eval(Object container, String expression)
at System.Web.UI.TemplateControl.Eval(String expression)
at ASP.managephotoalbum_aspx.__DataBinding__control16 (Object sender, EventArgs e) in C:\BegASPNET\Site\ManagePhotoAlbum.aspx:line 16
at System.Web.UI.Control.OnDataBinding(EventArgs e)
at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
at System.Web.UI.Control.DataBind()
at System.Web.UI.Control.DataBindChildren()
InnerException:

Code:

<%@ Page Title="Manage Photo Album" Language="VB" MasterPageFile="~/MasterPages/Frontend.master" AutoEventWireup="false" CodeFile="ManagePhotoAlbum.aspx.vb" Inherits="_ManagePhotoAlbum" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="cpMainContent" Runat="Server">
    <asp:ListView ID="ListView1" runat="server" DataKeyNames="Id" InsertItemPosition="LastItem" SelectMethod="ListView1_GetData" InsertMethod="ListView1_InsertItem" DeleteMethod="ListView1_DeleteItem">
    <InsertItemTemplate>
        <li>
            Description: <asp:TextBox ID="Description" runat="server" TextMode="MultiLine" Text='<%#Bind("Description")%>' /><br />
            ToolTip: <asp:TextBox ID="ToolTip" runat="server" Text='<%#Bind("ToolTip")%>' /><br />
            ImageUrl: <asp:TextBox ID="ImageUrl" runat="server" Text='<%#Bind("ImageUrl")%>' /><br />
            <asp:Button ID="InsertButton" runat="server" Text="Insert" CommandName ="Insert" />
        </li>
    </InsertItemTemplate>
    <ItemTemplate>
            Description: <asp:Label ID="Description" runat="server" Text='<%#Eval("Description")%>' /><br />
            Tooltip: <asp:Label ID="ToolTip" runat="server" Text='<%#Eval("ToolTip")%>' /><br />
            ImageUrl: <asp:Label ID="ImageUrl" runat="server" Text='<%#Eval("ImageUrl")%>' /><br />
            <asp:Button ID="DeleteButton" runat="server" CommandName="Delete" Text="Delete" CausesValidation="False" />
        </li>
    </ItemTemplate>
        <LayoutTemplate>
            <ul class ="ItemContainer">
                <li runat="server" id="itemPlaceholder"></li>
            </ul>
        </LayoutTemplate>
    </asp:ListView>
</asp:Content>