What are the requirements for a custom data source to be listed in the 'Data Source' drop-down list when adding a Dataset to a .rdlc report in Report Viewer 2010?
As can been seen from the screen grab, for some reason it is listing potential sources from a variety of referenced assemblies, but I can't see an obvious pattern as to why it is selecting these.
The 'GeneralDataSet' makes sense as that is a strongly-typed Dataset class, but I'm pretty sure most of the others are not, yet the design dialog still lists them.
I'm looking to roll my own custom data source and would prefer it to be selectable from this list.
I think it scans your project file looking for methods that return Lists<> and so on.
So something like:
public class Person
{
public string name { get; set; }
public int age { get; set; }
}
public class GetPeople
{
public List<Person> GetPeopleList()
{
return null;
}
public IEnumerable<Person> GetPeopleIEnumerable()
{
return null;
}
public IQueryable<Person> GetPeopleIQueryable()
{
return null;
}
}
All three show up, so take your pick. (Code is just thrashed out, ignore bad names/practices :))
But when you use a ReportViewer, you will need to manually set the datasets. Selecting it inside the report from what I have found just basically tells it what data to expect. So add an ObjectDataSource or just set it in the code behind.
I noticed the dataset does not appear if the source is exposed as a Property and not a method.
ie this fails to be a selectable data source.
public class FooData
{
public List<string> Data {get;set;}
}
but this will show up as a data source
public class FooData
{
public List<string> GetData();
}
I just had a problem with this also,
my class was returning Lists but would not show up in the datasources list.
I then added a parameterless constructor and it started to show up ( there was not one before ) I assmume this is so the reportviewer can create and instance of it.
eg:
public MyObject()
{
}
I've had a similar problem with custom lists which inherit from List.
You can work around it if your system will allow you to inherit without using interfaces. Ours doesn't.
The project containing this class WILL appear in the DataSource dropdown, and the class itself appears in the DataSet dropdown:
public class AccountList : List<AccountData>
{}
This class will NOT appear as a Dataset, which prevents its project from appearing as a DataSource (notice the "I" in front of AccountData):
public class AccountList : List<IAccountData>
{}
This is a pain because other aspects of our system require the lists to inherit from an interface not a concrete class. I don't know why it doesn't work.
Related
I have a control like this:
<ComboBox x:Name="ComboTipo"
Height="23"
SelectionChanged="ComboTipo_SelectionChanged"
Width="450"
Canvas.Left="609"
Canvas.Top="26" />
And my code is:
ComboTipo.DisplayMemberPath = "Descripcion";
ComboTipo.SelectedValuePath = "IdTipoPersona";
ComboTipo.ItemsSource = myWebServices.dameTipos();
My web services returns a list for this object, this class is created in automatic when i add the reference to the web services:
public partial class TipoPersona {
private short idTipoPersonaField;
private string descripcionField;
/// <comentarios/>
public short IdTipoPersona {
get {
return this.idTipoPersonaField;
}
set {
this.idTipoPersonaField = value;
}
}
/// <comentarios/>
public string Descripcion {
get {
return this.descripcionField;
}
set {
this.descripcionField = value;
}
}
}
But the problem is:
The combobox displays the data types for each element of the list, and i want display the Descripcion.
Can you help me plis! Thanks
What does IdTipoPersona look like? Is it a class you created? If so, you may need to reference the property that you want displayed. It would look something like this:
ComboTipoPersona.SelectedValuePath = "IdTipoPersona.Text";
Where Text would be replaced by the property. It is really hard to judge otherwise what is going on with knowing a little more about the object structure that myWebServices.dameTipos() returns.
EDIT
Ok I was able to simulate your problem and simulate a solution as well.
Your issue is in the Tipos class. There are a couple of things necessary when binding to a combobox with a custom class.
First off, you will want to add accessors and mutators (getters and setters) to IdTippoPersona and Descripcion.
You should add a constructor that assigns to those properties with parameters.
It is usually a good idea to add a default constructor.
The finished code will look like this:
public class Tipos
{
public int IdTipoPersona { get; set; }
public string Descripcion { get; set; }
public Tipos(int id, string descripcion)
{
IdTipoPersona = id;
Descripcion = descripcion;
}
}
I found the asnwer if someone needs it.
We need create a class intermediate class but we were working with entity framework, for this way, we need add the intermediate class like complex type in my model (entity framework).
And also we need override this class.
And it works so well.
Thanks for all #Goody
I'm writing a WPF application and I'm currently refactoring some reused code to a base ViewModel Class which my other viewmodels can inherit from.
One Property field on this base class is
public class MessageParentBase
{
MessageParentBase() {}
public string Name;
}
internal ObservableCollection<MessageParentBase> _GridData = new ObservableCollection<MessageParentBase>();
I have a subsequent property declaration
public ObservableCollection<MessageParentBase> GridData
{
get { return _GridData; }
set { _GridData = value; }
}
This works great and everything my issue is that the inerited classes actually use the follow class
Public class ChatMessage : MessageParentBase
{
public string Message;
}
and the view contains a grid of data which is bound to this GridData property but the column which should be bound to the Message field from the ChatMessage class is blank and the fields found in the MessageParentBase class are populated.
So I presume there is an issue with the view not knowing to cast up to the ChatMessage from the MessageParentBase class.
Can I inform the view that the objects will be of the type "ChatMessage".
I did try moving the property declaration up to the inherited viewmodel as
public ObservableCollection<ChatMessage> GridData
{
get { return _GridData; }
set { _GridData = value; }
}
but this gives me the following error:-
Cannot implicitly convert type 'System.Collections.ObjectModel.ObservableCollection' to 'System.Collections.ObjectModel.ObservableCollection'
Do I need to cast at the view level or can I change the viewmodels to implement this better?
Any suggestions would be greatly appreciated.
Emlyn
Change the collection to this:
public ObservableCollection<MessageParentBase> GridData { get; set; }
then add into your constructor
this.GridData = new ObservableCollection<MessageParentBase>();
Since WPF uses reflection to retrieve bound data from the data context it should be able to get the values of the derived classes stored in that collection.
Also when you run your application check the output window with Debug selected, the XAML engine will output any binding errors there.
Your ViewModel should contain a list with the type that your grid will show (in this case, the ChatMessage type). You can still use the inheritance to call common methods, but the binded list must be of the ChatMessage type
Is there any way that I use data annotation as the source of validation in WPF? I want to be able to define a class such as:
class myData
{
[Required]
[MaxLength(50)]
public string Name{get;set;}
}
And then bind it to a field in a view and the wpf validate that user enter some value for this field and also make sure that its length is not greater than 50. I know that I can write a validator for this, but then if I change the maxLength to say 60, then I need to change it in validator and I don't want to have changes in different places.
You need to create a "metadata" definition of the class. You'll need something like this:
[MetadataTypeAttribute(typeof(MyClass.MyClassMetadata))]
public partial class MyClass
{
internal sealed class MyClassMetadata
{
// Metadata classes are not meant to be instantiated.
private MyClassMetadata()
{
}
[Required]
[MaxLength(50)]
public string Name{ get; set; }
}
}
This extends the class with the necessary meta data to support the validation.
Since this question is still left unanswered and I came across it while answering another question that was looking for the same thing, I would share the solution of that question over here too.
The Microsoft TechNet article "Data Validation in MVVM" is a very clean and thorough implementation of using Data Annotations for validation in WPF. I read through the solution myself and would recommend it to others.
I know this must be an age-old, tired question, but I cant seem to find anything thru my trusty friend (aka Google).
I have a .net 3.5 c# winforms app, that presents a user with a login form on application startup. After a successful login, I want to run off to the DB, pull in some user-specific data and hold them (in properties) in a class called AppCurrentUser.cs, that can thereafer be accessed across all classes in the assembly - the purpose here being that I can fill some properties with a once-off data read, instead of making a call to the DB everytime I need to. In a web app, I would usually use Session variables, and I know that the concept of that does not exist in WinForms.
The class structure resembles the following:
public class AppCurrentUser {
public AppCurrentUser() { }
public Guid UserName { get; set; }
public List<string> Roles { get; set; }
public string Firstname { get; set; }
public string Lastname { get; set; }
}
Now, I have some options that I need some expert advice on:
Being a "dumb" class, I should make the properties non-static, instantiate the class and then set the properties...but then I will only be able to access that instance from within the class that it was created in, right?
Logically, I believe that these properties should be static as I will only be using the class once throughout the application (and not creating new instances of it), and it's property values will be "reset" on application close. (If I create an instance of it, I can dispose of it on application close)
How should I structure my class and how do I access its properties across all classes in my assembly? I really would appreciate your honest and valued advice on this!!
Thanks!
Use the singleton pattern here:
public class AppUser
{
private static _current = null;
public static AppUser Current
{
get { return = _current; }
}
public static void Init()
{
if (_current == null)
{
_current = new AppUser();
// Load everything from the DB.
// Name = Dd.GetName();
}
}
public string Name { get; private set; }
}
// App startup.
AppUser.Init();
// Now any form / class / whatever can simply do:
var name = AppUser.Current.Name;
Now the "static" things are thread-unsafe. I'll leave it as an exercise of the reader to figure out how to properly use the lock() syntax to make it thread-safe. You should also handle the case if the Current property is accessed before the call to Init.
It depends on how you setup your architecture. If you're doing all your business logic code inside the actual form (e.g. coupling it to the UI), then you probably want to pass user information in as a parameter when you make a form, then keep a reference to it from within that form. In other words, you'd be implementing a Singleton pattern.
You could also use Dependency Injection, so that every time you request the user object, the dependency injection framework (like StructureMap) will provide you with the right object. -- you could probably use it like a session variable since you'll be working in a stateful environment.
The correct place to store this type of information is in a custom implementation of IIdentity. Any information that you need to identify a user or his access rights can be stored in that object, which is then associated with the current thread and can be queried from the current thread whenever needed.
This principal is illustrated in Rocky Lhotka's CLSA books, or google winforms custom identity.
I'm not convinced this is the right way but you could do something like this (seems to be what you're asking for anyway):
public class Sessions
{
// Variables
private static string _Username;
// properties
public static string Username
{
get
{
return _Username;
}
set
{
_Username = value;
}
}
}
in case the c# is wrong...i'm a vb.net developer...
then you'd just use Sessions.USername etc etc
Ok, so having given up on getting the built in .NET configuration system to save/load data about a custom object per user, I have moved to using a serializable object. And, to go a step further, I'd like to bind it to my controls in the options window of my application.
Please forgive the length of this question as it has some chunks of code in it...
First, the parent object:
[Serializable]
public class ConnectionSettings
{
public List<Connection> Connections { get; set; }
public ConnectionSettings()
{
Connections = new List<Connection>();
}
}
Because there will be multiple connections that will be saved, I figured this would be the easiest way to store them.
A chunk of the Connection object:
[Serializable]
public class Connection : NotifyBase
{
private string hostName;
[DisplayName( "Host Name" )]
public string HostName
{
get { return hostName; }
set { SetField( ref hostName, value, "HostName" ); }
}
/* Other field snipped for your sanity,*/
/* same format as host name */
public List<string> Channels { get; set; }
public Connection()
{
Channels = new List<string>();
}
}
For a general idea of how the form looks like:
I have a ComboBox that will display the Host Name of all the saved connections, when the user selects a Host Name, it will populate the other fields on the form with their respective values. I realize this shouldn't be so hard, but for some reason, I can't get the combo box portion working, and the more I think about it, I'm not sure If I know how to know which particular connection to populate the other controls with...
more info
The problem is, I'm not sure how to bind everything that needs binding. I was going off of this example. What I'd like to be able to do is for every Connection object in the deserialized ConnectionSettings (from a file) display the host name in the combo box, and when you select a host name, it fill in the rest of the related data to the other controls on the form.
Any help ill be greatly appreciated.
Ok, I think I've figured it out. I changed the ConnectionSettings to inherit List and it seems to be working correctly.