Chapter 14, Listview control problem

SamuelMSr · September 28th, 2011, 02:16 PM

I am working through the Try It Out that starts on page 505 and have gotten to page 510 where it says to launch NewPhotoAlbum.asxp and put in a name for an album and click Insert.

When I click insert instead of being directed to the ManagePhotoAlbum.aspx page I get the following error:

Code:

Server Error in '/' Application.
For the EntityDataSource, either Type or DbType (but not both) must be specified for each Parameter.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: For the EntityDataSource, either Type or DbType (but not both) must be specified for each Parameter.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[InvalidOperationException: For the EntityDataSource, either Type or DbType (but not both) must be specified for each Parameter.]
   System.Web.UI.WebControls.EntityDataSourceView.ExecuteSelect(DataSourceSelectArguments arguments) +738
   System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback) +21
   System.Web.UI.WebControls.DataBoundControl.PerformSelect() +143
   System.Web.UI.WebControls.ListView.PerformSelect() +113
   System.Web.UI.WebControls.BaseDataBoundControl.DataBind() +74
   System.Web.UI.WebControls.BaseDataBoundControl.EnsureDataBound() +66
   System.Web.UI.WebControls.ListView.CreateChildControls() +55
   System.Web.UI.Control.EnsureChildControls() +102
   System.Web.UI.Control.PreRenderRecursiveInternal() +42
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2496

Here is the code from my ManagePhotoAlbum.aspx:

Code:

<%@ Page Title="Manage Photo Album" Language="C#" MasterPageFile="~/MasterPages/Frontend.master" AutoEventWireup="true" CodeFile="managePhotoAlbum.aspx.cs" 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" 
        DataSourceID="EntityDataSource1" InsertItemPosition="LastItem">
        <InsertItemTemplate>
            <li style="">
                Description:
                <asp:TextBox ID="DescriptionTextBox" runat="server" 
                    Text='<%# Bind("Description") %>' />
                <br />
                Tooltip:
                <asp:TextBox ID="TooltipTextBox" runat="server" Text='<%# Bind("Tooltip") %>' />
                <br />
                ImageUrl:
                <asp:TextBox ID="ImageUrlTextBox" runat="server" 
                    Text='<%# Bind("ImageUrl") %>' />
                <br />
                <asp:Button ID="InsertButton" runat="server" CommandName="Insert" 
                    Text="Insert" />
                <asp:Button ID="CancelButton" runat="server" CommandName="Cancel" 
                    Text="Clear" />
            </li>
        </InsertItemTemplate>
        <ItemTemplate>
            <li style="">
                Description:
                <asp:Label ID="DescriptionLabel" runat="server" 
                    Text='<%# Eval("Description") %>' />
                <br />
                Tooltip:
                <asp:Label ID="TooltipLabel" runat="server" Text='<%# Eval("Tooltip") %>' />
                <br />
                ImageUrl:
                <asp:Label ID="ImageUrlLabel" runat="server" Text='<%# Eval("ImageUrl") %>' />
                <br />
                <asp:Button ID="DeleteButton" runat="server" CommandName="Delete" 
                    Text="Delete" />
            </li>
        </ItemTemplate>
        <LayoutTemplate>
            <ul class="ItemContainer">
                <li runat="server" id="itemPlaceholder" />
            </ul>
        </LayoutTemplate>
    </asp:ListView>
    <asp:EntityDataSource ID="EntityDataSource1" runat="server" 
        ConnectionString="name=PlanetWroxEntities" 
        DefaultContainerName="PlanetWroxEntities" EnableDelete="True" 
        EnableFlattening="False" EnableInsert="True" EntitySetName="Pictures" 
        Where="it.PhotoAlbumId = @photoAlbumId" 
    oninserting="EntityDataSource1_Inserting" EntityTypeFilter="" Select="">
        <WhereParameters>
            <asp:QueryStringParameter Name="PhotoAlbumId" QueryStringField="PhotoAlbumId" />
        </WhereParameters>
    </asp:EntityDataSource>
</asp:Content>

And here is the code from my code behind file:

Code:

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

public partial class _managePhotoAlbum : BasePage
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void EntityDataSource1_Inserting(object sender, EntityDataSourceChangingEventArgs e)
    {
        int photoAlbumId = Convert.ToInt32(Request.QueryString.Get("PhotoAlbumId"));
        Picture myPicture = (Picture)e.Entity;
        myPicture.PhotoAlbumId = photoAlbumId;
    }
}

Please let me know if you need further information and thanks in advance for any help you may be able to provide.

Sam

SamuelMSr · September 28th, 2011, 02:35 PM

I was able to fix this, even if I am not sure the exact "why" of it. I compared my code to the source code for the chapter that I downloaded and found out I was missing the following code on my aspx page:

Code:

...
<WhereParameters>             <asp:QueryStringParameter Name="PhotoAlbumId" QueryStringField="PhotoAlbumId" Type="Int32" />         </WhereParameters>
...

I followed the directions in the book very well, or at least I thought I did so I do not understand why that part would be missing. I am just glad I found it.

If someone can explain the "why" factor here or what step I may have missed to get that part in I would appreciate it, that is the best way to learn.

Thanks!!

Imar · September 28th, 2011, 02:45 PM

Hi Sam,

Did you also carry out the step below image 14-13:

Quote:

Make sure you enter it.PhotoAlbum.Id = @photoAlbumId in the Where Expression box at the top of the dialog. Next, click the Show Advanced Properties link and change the Type property of the parameter to Int32. When youâre done, click OK to dismiss the dialog box.

Cheers,

Imar

SamuelMSr · September 28th, 2011, 02:47 PM

You know, Imar,

I do not remember if I did or not, its so easy when working on this stuff after about the 7th hour in the day to start wanting to go to fast through the book. And when I went back to read it the second time I missed it for sure.

Thank you for pointing that out to me and I will be more careful next time.