ReportViewer in LocalReport Mode With Subreports And Business Objects

There are not many good examples of how to do stuff like this.  So the article below was all the more helpful when I was building a somewhat complex report.

http://www.codeproject.com/dotnet/AdoNetForOopPart2.asp?df=100&forumid=258341&select=1482558&msg=1482558

 

Run ASP.NET Web Server From Any Folder

Rob McLaws has this cool extension that lets you click on a folder and run a webserver from it.

The article, with some comments on alternative ways to do it, or ways to improve it can be found here.

http://weblogs.asp.net/rmclaws/archive/2005/10/25/428422.aspx

From the page:

I’ve been doing some web development work again lately, and I haven’t wanted to screw with setting up IIS on my virtual machine. The .NET Framework 2.0 comes with a built-in webserver, based on the old Cassini web server. So I wanted to be able to easily set up any directory to have its contents served up on an as-needed basis. The result is an addition to the Windows Explorer right-click menu, as shown below:

This is enabled by a simple modification to the registry. You can take the text below and dump it into a file named “WebServer.reg”, and then run it, to immediately get the item in the context menu.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINESOFTWAREClassesFoldershellVS2005 WebServer]
@=”ASP.NET 2.0 Web Server Here”

[HKEY_LOCAL_MACHINESOFTWAREClassesFoldershellVS2005 WebServercommand]
@=”C:\Windows\Microsoft.NET\Framework\v2.0.50727\Webdev.WebServer.exe /port:8080 /path:”%1″”

There are a couple caveats to this tool, however:

  1. The web server does not randomly assign a port number, so it has to be hard-coded into the registry.
  2. The web server does not automatically assign a virtual directory, so it will always be “http://localhost:port”
  3. A command prompt window will be spawned, and cannot be closed without closing the web server process.

Moving foward, there are a couple of options to fix these issues:

  1. Someone who knows more about variables in the registry can help me fix issues #2 and #3
  2. I can build a wrapper executable that solves all three problems
  3. Microsoft can put in a DCR and fix it before it goes gold in a few days.

#3 is not likely, so I’d love to hear what you think. Hope this trick is useful.

 

Dropdown1 has a SelectedValue which is invalid because it does not exist in the list of items.

‘Dropdown1’ has a SelectedValue which is invalid because it does not exist in the list of items.
Parameter name: value

This error has been a real pain to deal with.  I finally have a work around and a guess at the underlying problem, and because I see that people are having this same problem I thought I would do a little writeup about it.

 

Obviously, if you look at the actual error message, there are cases when you can get this message and the problem is easy to solve.  e.g. you have a dropdown populated with EmploID values and you try to databind with: 

Value=’<%# Bind(“EmployeeName”) %>

 
Well of course that won’t work if all your values are integers and you are trying to set the value to “Bill Smith”.
 
But my problem was a bit more complicated.
 
I was building a web user control (aka ASCX) that was a “Location” dropdown.  The control basically contains a dropdown, and all the necessary logic to populate the dropdown, and I was trying to use this control inside the EditTemplate of a GridView.
 
To make things more complicated, in this case, I didn’t JUST want all the Locations, I also wanted to add a “Please Select” item to the list, with a value of 0.
 
But I kept getting the error above when the value was supposed to be 0.
 
I stepped through my code to try to find out what was going on.  I believe the issue is this:
 
On load, on value set, and on databind I call my “Populate” method.  This method sees if there are items in the dropdown.  If not, it gets a list from the database and binds to the dropdown.  It also checks if there is a “Please Select” item, and adds it if there isn’t one.
 
But still when Dropdown’s “DataBound” event was fired the last time, my manually added item had been removed.
 
So what I think what is happening is that :
1) I set the dropdown DataSource to a collection of business objects
2) I add the “Please Select” item
3) The dropdown is told to databind itself by the Gridview.
4) The dropdown says… “Oh, I do have a datasource, so I’m going to ditch my current list and rebind to that old collection”
5) The dropdown says “Holy shnikies, I am supposed to bind to value “0”, but I don’t have one!!”
 
I think there are 2 possible solutions.
 
1) I created an adapter class that only has Id and Description properties that are going to be used by the control, and I wrote a function to take my collection of business objects and build a collection of Adapters (adding my “Please Select”) to the list of adapters.  To see what I am talking about I will post this code below.
 
2) Manually add items to the dropdown instead of databinding, so that when the control is told to databind, it doesn’t have a datasource to use.
 
 
Here is my adapter code:
            '**** In my populate method
Me.LocationsDropdown.DataSource = LocationAdapter.LocationsToAdapters(locations)
Me.LocationsDropdown.DataTextField = "LocationDescriptionWithActiveAttribute"
Me.LocationsDropdown.DataValueField = "LocationId"
Me.LocationsDropdown.DataBind()



'*************************************
'*************************************




Private Class LocationAdapter
Public ciLocationId As Integer
Public csLocationDescriptionWithActiveAttribute As String
Public Property LocationId() As Integer
Get
Return ciLocationId
End Get
Set(ByVal value As Integer)
Me.ciLocationId = Value
End Set
End Property

Public Property LocationDescriptionWithActiveAttribute() As String
Get
Return csLocationDescriptionWithActiveAttribute
End Get
Set(ByVal value As String)
Me.csLocationDescriptionWithActiveAttribute = Value
End Set
End Property

Public Sub New(ByVal loc As Location)
Me.LocationId = loc.LocationId
Me.LocationDescriptionWithActiveAttribute = loc.LocationDescriptionWithActiveAttribute
End Sub
Public Sub New(ByVal Id As Integer, ByVal Desc As String)
Me.LocationId = Id
Me.LocationDescriptionWithActiveAttribute = Desc
End Sub

Public shared Function LocationsToAdapters(ByVal locations As List(Of Location)) As List(Of LocationAdapter)
Dim adapters As New List(Of LocationAdapter)
adapters.Add(New LocationAdapter(0, "--Location"))
For Each loc As Location In locations
adapters.Add(New LocationAdapter(loc))
Next
Return adapters
End Function

End Class
 
 
 

Adding a Single Project To Source Control?

In previous versions of VS.Net you could take a project and go File->Source Control->Add Selected Project To Source Control and you could simply add the project to your VSS provider.

Now in VS.Net 2005 (maybe caused by VSS 2005, or VSS 2005 over HTTP), if you follow this route you will end up with File->Source Control->Add Project to Source Control, and your project will be added with the following path:

$MyProject.rootMyProject.

Thanks VSS, thanks a lot.  I really needed that .root in there.

To get around this problem, just add another existing project to VS.Net (creating a solution).  Now highlight the actual project you want to add and do:

File->Source Control->Add Selected Project to Source Control and all will be wonderful.

ASP.NET 2.0 Page Life-cycle

This table is from: http://www.csharper.net/blog/page_lifecycle_methods_in_asp_net_2_0.aspx

 

Method Postback Control
Constructor Always All
Construct Always Page
TestDeviceFilter Page
Used to determine which device filter is in place, and use this information to decide how to display the page.
AddParsedSubObject Always All
Notifies the server control that an element, either XML or HTML, was parsed, and adds the element to the server control’s ControlCollection object.
DeterminePostBackMode Always Page
Returns a NameValueCollection object that contains the data posted back to the page. The presence of the page hidden fields VIEWSTATE and EVENTTARGET is used to help determine whether a postback event has occurred. The IsPostBack property is set when the DeterminePostBackMode method is called.
OnPreInit Always Page
Called at the beginning of the page initialization stage. After the OnPreInit method is called, personalization information is loaded and the page theme, if any, is initialized. This is also the preferred stage to dynamically define a PageTheme or MasterPage for the Page.
OnInit Always All
Performs the initialization and setup steps required to create a Page instance. In this stage of the page’s life cycle, declared server controls on the page are initialized to their default state; however, the view state of each control is not yet populated. A control on the page cannot access other server controls on the page during the Page_Init phase, regardless of whether the other controls are child or parent controls. Other server controls are not guaranteed to be created and ready for access.
OnInitComplete Always Page
Called after page initialization is complete. In this stage of the page’s life cycle, all declared controls on the page are initialized, but the page’s view state is not yet populated. You can access server controls, but they will not yet contain information returned from the user.
LoadPageStateFromPersistenceMedium Postback Page
Uses the Load method of the System.Web.UI.PageStatePersister object referenced by the PageStatePersister property to load any saved view-state information for the Page object.
LoadControlState Postback All
Restores control-state information from a previous page request that was saved by the SaveControlState method.
LoadViewState Postback All
Restores view-state information from a previous page request that was saved by the SaveViewState method.
OnPreLoad Always Page
Called after all postback data returned from the user is loaded. At this stage in the page’s life cycle, view-state information and postback data for declared controls and controls created during the initialization stage are loaded into the page’s controls. Controls created in the OnPreLoad method will also be loaded with view-state and postback data.
OnLoad Always All
Notifies the server control that it should perform actions common to each HTTP request for the page it is associated with, such as setting up a database query. At this stage in the page lifecycle, server controls in the hierarchy are created and initialized, view state is restored, and form controls reflect client-side data.
RaisePostBackEvent Postback All
Notifies the server control that caused the postback that it should handle an incoming postback event.
OnLoadComplete Always Page
At this point in the page life cycle, all postback data and view-state data is loaded into controls on the page.
OnPreRender Always All
Notifies the server control to perform any necessary prerendering steps prior to saving view state and rendering content.
OnPreRenderComplete Always Page
At this stage of the page life cycle, all controls are created and the page is ready to render the output. This is the last event called before the page’s view state is saved.
SaveControlState Always All
Saves any server control state changes that have occurred since the time the page was posted back to the server. If there is no state associated with the control, this method returns a null reference. Custom controls using control state must call the RegisterRequiresControlState method on the Page before saving control state.
SaveViewState Always All
Saves any server control view-state changes that have occurred since the time the page was posted back to the server. If there is no view state associated with the control, this method returns a null reference.
SavePageStateToPersistenceMedium Always Page
Saves any view-state and control-state information for the page. The SavePageStateToPersistenceMedium method uses the Save method of the System.Web.UI.PageStatePersister object referenced by the PageStatePersister property to store view-state and control-state information for the page.
Render Always All
Initializes the HtmlTextWriter object and calls on the child controls of the Page to render. The Render method is responsible for creating the text and markup that is sent to the client browser. The default Render method calls RenderChildren to write the text and markup for the controls contained on the page.
OnUnload Always All
Used to do target-specific processing in the Unload stage of the control lifecycle. Typically, these are cleanup functions that precede disposition of the control.

VS2005 VB.Net Create Properties From Private Fields

“Refactor!” has the ability to turn your fields into public accessible properties, but it kinda sucks because 1) you have to do it 1 at a time, and 2) the naming convetion is all wrong. 

For example if you have a private integer called myInt then your property will be MyInt1.  Not exaclty what I am looking for.

So I updated my 2002 macro for creating these properties.  It should allow you to follow a variety of naming conventions “m_XXX”, “ciXXX”, “strXXX” etc.

Just include the macro below, then just highlight your private fields, and run the macro.

   ' highlight the private properties
Public Sub AddClassProperties()

Dim oTextSelection As TextSelection = DTE.ActiveWindow.Selection
Dim iLinesSelected = oTextSelection.TextRanges.Count
Dim colPropertyList As New Collection()
Dim iIndex As Integer
Dim oStart As EditPoint = oTextSelection.TopPoint.CreateEditPoint()
Dim oEnd As TextPoint = oTextSelection.BottomPoint

'Create an Undo context object so all the changes can be
'undone by CTRL+Z
Dim oUnDo As UndoContext = DTE.UndoContext

'Supress the User Interface. This will make it run faster
'and make all the changes appear once
DTE.SuppressUI = True

Try

oUnDo.Open("Comment Line")

Dim sProperty As String
Dim sLineOfText As String

Do While (oStart.LessThan(oEnd))

sLineOfText = oStart.GetText(oStart.LineLength).Trim
'*** do some kind of simple check to make sure that this line
'*** isn't blank and isn't some other kind of code or comment
If (sLineOfText.IndexOf(" As ") >= 0 And ( _
(sLineOfText.IndexOf("Public ") >= 0) Or _
(sLineOfText.IndexOf("Private ") >= 0) Or _
(sLineOfText.IndexOf("Dim ") >= 0) Or _
(sLineOfText.IndexOf("Protected ") >= 0) Or _
(sLineOfText.IndexOf("Friend ") >= 0) Or _
(sLineOfText.IndexOf("ReDim ") >= 0) Or _
(sLineOfText.IndexOf("Shared ") >= 0) Or _
(sLineOfText.IndexOf("Static ") >= 0) _
)) Then

sProperty = oStart.GetText(oStart.LineLength).Trim.Replace(" New ", " ").Replace("()", "")

colPropertyList.Add(sProperty)
End If

oStart.LineDown()
oStart.StartOfLine()

Loop

If colPropertyList.Count > 0 Then

For Each sProperty In colPropertyList
Call InsertProperty(sProperty)
Next

Else
MsgBox("You must select the class properties")
End If

Catch ex As System.Exception

Debug.WriteLine(ex)
If MsgBoxResult.Yes = MsgBox("Error: " & ex.ToString & vbCrLf & "Undo Changes?", MsgBoxStyle.YesNo) Then
oUnDo.SetAborted()
End If

Return
Finally

'If an error occured, then need to make sure that the undo context is cleaned up.
'Otherwise, the editor can be left in a perpetual undo context
If oUnDo.IsOpen Then
oUnDo.Close()
End If

DTE.SuppressUI = False
End Try


End Sub

Private Sub InsertProperty(ByVal sProp As String)
Dim oTextSelection As TextSelection = DTE.ActiveWindow.Selection
Dim sMember As String = sProp.Substring(sProp.IndexOf(" ")).Trim
Dim sDataType As String
Dim sName As String
Dim i As Integer
Dim iAscVal As Integer

i = sMember.IndexOf("(")
If Not i = -1 Then
sMember = sMember.Substring(0, i)
End If

i = sMember.IndexOf("=")
If Not i = -1 Then
sMember = sMember.Substring(0, i)
End If

sDataType = sMember.Substring(sMember.IndexOf(" As ") + 1)

For i = 0 To sMember.Length - 1
'iAscVal = Asc(Mid(sName, i, 1))
iAscVal = Asc(sMember.Chars(i))
If iAscVal > 64 And iAscVal < 91 Then
sName = sMember.Substring(i)
Exit For
End If
Next i

sName = sName.Substring(0, sName.IndexOf(" As ") + 1).Trim

If sName.Length = 0 Then
MsgBox("Unable to process the class property: " & sMember & ". This is usually caused by an incorrect naming convention (e.g. not cxName)")
Return
End If

sMember = sMember.Substring(0, sMember.Length - sDataType.Length).Trim

With oTextSelection
.MoveToPoint(.ActivePoint.CodeElement(vsCMElement.vsCMElementClass).GetEndPoint(vsCMPart.vsCMPartWhole))
.LineUp()
.EndOfLine()

.Text = "Public Property " & sName & "() " & sDataType
.NewLine()
.Text = "Return " & sMember
.StartOfLine(vsStartOfLineOptions.vsStartOfLineOptionsFirstText)
.StartOfLine(vsStartOfLineOptions.vsStartOfLineOptionsFirstColumn, True)
.Copy()
.LineDown(False, 3)
DTE.ExecuteCommand("Edit.Paste")
.Text = "Me." & sMember & " = Value"
.LineDown(False, 2)
.NewLine(2)

End With

End Sub

 

 

Update1: When using code that you cut and paste from here, you might need to first paste it into Word or Wordpad.

Update2: When using this macro, you need a space (new line) between the last private field variable and your end of class line.

applicationSettings, appSettings. app.config, web.config and userSettings

I have seen lots of posts from people in the newsgroups trying to figure out what the deal is with the new config options in .net 2.0.

The main reason people run into problems is due to MS making a number of changes, including changes between the beta and the RC product, resulting in different answers based on how early you encountered the issues.

You can still do things the way you did with .Net 1.x.

       <appSettings>

              <add key=MyKeyName value=somevalue/>

       </appSettings>

and then you can access it with:

Dim myvalue As String = System.Configuration.ConfigurationSettings.AppSettings.Item(“ConnectionString”)

However, if you try this, VS.Net will warn you:

This method is obsolete, it has been replaced by System.Configuration!System.Configuration.ConfigurationManager.AppSettings

It is important to note that the “!” above indicates that the fully quallified class listed, is located in the System.Configuration assembly, which of course you have to add to your project. 

So unlike previous versions, you need to manually add a reference to System.Configuration in order to make this new call.

Now, .net 2.0 and vs.net 2005 have teamed up to offer a new option for storing user settings which may seem more complicated at first if you don’t know exactly what you are doing.  In the project properties you can select a “Settings” tab where you are able to modify application settings, which are in turn stored in app.config.  These settings can either be “User” settings, or “Application” settings. 

Application settings are stored in the app.config (or web.config), and are read-only.  User settings have a default value that is stored in the app.config, but your application can overwrite these default values as needed, and the users settings will be stored in:

%USERPROFILE%Local SettingsApplication Data<Company Name><appdomainname>_<eid>_<hash><verison>user.config. (non roaming)

OR:

%USERPROFILE%Application Data<Company Name><appdomainname>_<eid>_<hash><verison>user.config (roaming)

The other nice feature of the 2.0 way of accessing these settings is that the settings are saved as a specific type from a wide collection of available types (String, System.DateTime, System.Drawing.Color, System.Guid, Bool, StringCollection etc) and when you access them from your code they are available in intellisense.

This may seem like it isn’t important, but it means you can’t mistype a setting key, or accidently try an invalid cast from one of your settings.  Also, storing a collection was a real pain in 1.x.    Now you can create a collection quickly and it will be added to the user settings like this:

   <setting name=MyCol serializeAs=Xml>

        <value>

            <ArrayOfString xmlns:xsi=http://www.w3.org/2001/XMLSchema-instance

                xmlns:xsd=http://www.w3.org/2001/XMLSchema>

                <string>I am first</string>

                <string>second</string>

                <string>me third</string>

                <string>I am number four</string>

            </ArrayOfString>

        </value>

    </setting>

Pretty nice!

To access these properties you have 2 different ways depending on if you are using VB.Net or C#.

For VB.Net you use the “My” namespace and access it like this:

Dim mySetting As String = My.Settings.MySetting

For C# you access these settings through the “Properties” object

       string mySetting = Properties.Settings.Default.MyUserSetting;

That’s it!

Serialization / Deserialization of Objects With Version Changes

CSLA as well as well as the proxy architecture I created for my last project, utilize serialization of objects to be passed across the wire, and deserialized on the other side into the same type of object.

This is different from passing datasets, which are then read into business objects.  We are actually passing the serialized version of the business object.

So what happens if you make a change to a business object such as adding a public property.  Will clients who have the old version of the Business Object be forced to upgrade? 

To see the answers along with some sample code for testing this out click on the link to read the full article.

So lets say you have a class that exposes 20 properties and 40 methods.  This business object is deployed on hundreds of clients computers.  When they send the BizObject over the wire, it is deserialized back into the exact same object on the server. 

But now, for whatever reason, you need to add 1 property to this BizObject.  For the current set of clients using this business object, you don’t really need to deploy the updated change unless you have to in order to keep it from breaking.

So do you need to redeploy?  Probably not.

I serialzied a business object into a base64 encoded string and then added a public property to the object and tried to deserialize it with the “old” serialized string.  The result?  It worked.  The properties that had values when I first serialized it kept their values.  The fact that there were new properties didn’t cause a problem.

How about going the other way: removing a public property that had a value when it was serialized, but doesn’t exist with deserialized.  Again, this works. 

When doesn’t it work?  When you are trying to deserialze into a different class, or a different namespace for the same class. 

So you can’t serialize classA and deserialize it into classB, even if both expose the exact same signature.  The same goes for namespaces.  If you serialize classA, and then change it’s namespace and try to deserialize it, you will get an exception.

You can try it out with the following code:

Imports WindowsApplication1.ASDF


Public Class Form1

Private Sub toString_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdToString.Click
Dim o As New A
o.A11 = "this is a test"
o.Asdf1 = "another test"

Me.TextBox2.Text = EncodeBase64(o.CloneString)
MsgBox(EncodeBase64(o.CloneString))
End Sub

Private Sub fromString_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles fromString.Click
Dim o As A = A.Hydrate(DecodeBase64(Me.TextBox1.Text))
MsgBox(o.A11)
MsgBox(o.Asdf1)
MsgBox(o.asdfdsa)
End Sub

Public Function EncodeBase64(ByVal input As String) As String
Dim strBytes() As Byte = System.Text.Encoding.UTF8.GetBytes(input)
Return System.Convert.ToBase64String(strBytes)
End Function

Public Function DecodeBase64(ByVal input As String) As String
Return System.Text.Encoding.UTF8.GetString(System.Convert.FromBase64String(input
))
End Function

End Class


<Serializable()> _
Public Class Parent

Public Function CloneString() As String
Dim bFormatter As New System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
Dim stream As New System.IO.MemoryStream()
bFormatter.Serialize(stream, Me)
stream.Flush()
stream.Position = 0
Dim bytes() As Byte = stream.ToArray()

Return System.Text.Encoding.Default.GetString(bytes)
End Function

Public Shared Function StringToStream(ByVal str As String) As System.IO.Stream
Return New System.IO.MemoryStream(System.Text.Encoding.Default.GetBytes(str))
End Function

End Class

<Serializable()> _
Public Class A
Inherits Parent

Private a1 As String
Private asdf As String
Public Property A11() As String
Get
Return a1
End Get
Set(ByVal value As String)
a1 = value
End Set
End Property

Public Property Asdf1() As String
Get
Return asdf
End Get
Set(ByVal value As String)
asdf = value
End Set
End Property
Public Function asdfdsa() As String
Return "Asdf"
End Function
Public Shared Function Hydrate(ByVal s As String) As A
Dim bFormatter As New System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
Dim stream2 As System.IO.MemoryStream = StringToStream(s)
stream2.Flush()
stream2.Position = 0
Dim newClone As A
newClone = CType(bFormatter.Deserialize(stream2), A)
Return newClone
End Function

End Class