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  • How to validate a ComboBox programatically?

    - by PhOeNiX
    How can i validate a ComboBox for null entry? My combobox is in a model as i am generating it dynamically. Now what i want is that when the the columns are generated dynamically, the border of combobox should be red as no value is selected and once the value is selected the border shud become normal. The following is my combobox in model : DataGridTemplateColumn dataGridComboBoxTemplateColumnObj = new DataGridTemplateColumn(); dataGridComboBoxTemplateColumnObj.Header = column.Header; FrameworkElementFactory comboBoxFactory = new FrameworkElementFactory(typeof(ComboBox)); Binding bindingItemSourceObj = new Binding(column.ItemsSourcePropertyName); comboBoxFactory.SetValue(ComboBox.HorizontalAlignmentProperty, HorizontalAlignment.Stretch); comboBoxFactory.SetValue(ComboBox.ItemsSourceProperty, bindingItemSourceObj); comboBoxFactory.SetValue(ComboBox.SelectedValuePathProperty, column.ValuePropertyName); dataGridComboBoxTemplateColumnObj.CellTemplate = new DataTemplate(); dataGridComboBoxTemplateColumnObj.CellTemplate.VisualTree = comboBoxFactory;

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  • StockTrader RI > Controllers, Presenters, WTF?

    - by SandRock
    I am currently learning how to make advanced usage of WPF via the Prism (Composite WPF) project. I watch many videos and examples and the demo application StockTraderRI makes me ask this question: What is the exact role of each of the following part? SomethingService: Ok, this is something to manage data SomethingView: Ok, this is what's displayed SomethingPresentationModel: Ok, this contains data and commands for the view to bind to (equivalent to a ViewModel). SomethingPresenter: I don't really understand it's usage SomethingController: Don't understand too I saw that a Presenter and a Controller are not necessary but I would like to understand why they are here. Can someone tell me their role and when to use them?

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  • How to do the processing and keep GUI refreshed using databinding?

    - by macias
    History of the problem This is continuation of my previous question How to start a thread to keep GUI refreshed? but since Jon shed new light on the problem, I would have to completely rewrite original question, which would make that topic unreadable. So, new, very specific question. The problem Two pieces: CPU hungry heavy-weight processing as a library (back-end) WPF GUI with databinding which serves as monitor for the processing (front-end) Current situation -- library sends so many notifications about data changes that despite it works within its own thread it completely jams WPF data binding mechanism, and in result not only monitoring the data does not work (it is not refreshed) but entire GUI is frozen while processing the data. The aim -- well-designed, polished way to keep GUI up to date -- I am not saying it should display the data immediately (it can skip some changes even), but it cannot freeze while doing computation. Example This is simplified example, but it shows the problem. XAML part: <StackPanel Orientation="Vertical"> <Button Click="Button_Click">Start</Button> <TextBlock Text="{Binding Path=Counter}"/> </StackPanel> C# part (please NOTE this is one piece code, but there are two sections of it): public partial class MainWindow : Window,INotifyPropertyChanged { // GUI part public MainWindow() { InitializeComponent(); DataContext = this; } private void Button_Click(object sender, RoutedEventArgs e) { var thread = new Thread(doProcessing); thread.IsBackground = true; thread.Start(); } // this is non-GUI part -- do not mess with GUI here public event PropertyChangedEventHandler PropertyChanged; public void OnPropertyChanged(string property_name) { if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs(property_name)); } long counter; public long Counter { get { return counter; } set { if (counter != value) { counter = value; OnPropertyChanged("Counter"); } } } void doProcessing() { var tmp = 10000.0; for (Counter = 0; Counter < 10000000; ++Counter) { if (Counter % 2 == 0) tmp = Math.Sqrt(tmp); else tmp = Math.Pow(tmp, 2.0); } } } Known workarounds (Please do not repost them as answers) Those two first are based on Jon ideas: pass GUI dispatcher to library and use it for sending notifications -- why it is ugly? because it could be no GUI at all give up with data binding COMPLETELY (one widget with databinding is enough for jamming), and instead check from time to time data and update the GUI manually -- well, I didn't learn WPF just to give up with it now ;-) and this is mine, it is ugly, but simplicity of it kills -- before sending notification freeze a thread -- Thread.Sleep(1) -- to let the potential receiver "breathe" -- it works, it is minimalistic, it is ugly though, and it ALWAYS slows down computation even if no GUI is there So... I am all ears for real solutions, not some tricks.

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  • Distinguish UI change to variable from code-behind change

    - by Jay
    Like the title says I am trying to architecture into my application a way to distinguish the source of a variable change, either from UI or code-behind. My problem is that I need to trigger some action after a property changed its value, but I only need to do this when the change comes from the UI because otherwise I don-t want to perform that action. I am having some trouble because, for example when a checkbox(two way binding), changes state, my binded property gets updated and then I use the checked and uncheked events to trigger that action.The problem is that when I change the property in codebehind it also triggers those events and I do not want that. Right now, i am using a flag that enables, or not, the actions at the event handlers but I do not feel that this is a good idea. Any sugestions or ideas? I am considering using only one-way binding and control everything my self, using commands.

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  • Unable to add item to dataset in Linq to SQL

    - by Mike B
    I am having an issue adding an item to my dataset in Linq to SQL. I am using the exact same method in other tables with no problem. I suspect I know the problem but cannot find an answer (I also suspect all i really need is the right search term for Google). Please keep in mind this is a learning project (Although it is in use in a business) I have posted my code and datacontext below. What I am doing is: Create a view model (Relevant bits are shown) and a simple wpf window that allows editing of 3 properties that are bound to the category object. Category is from the datacontext. Edit works fine but add does not. If I check GetChangeSet() just before the db.submitChanges() call there are no adds, edits or deletes. I suspect an issue with the fact that a Category added without a Subcategory would be an orphan but I cannot seem to find the solution. Command code to open window: CategoryViewModel vm = new CategoryViewModel(); AddEditCategoryWindow window = new AddEditCategoryWindow(vm); window.ShowDialog(); ViewModel relevant stuff: public class CategoryViewModel : ViewModelBase { public Category category { get; set; } // Constructor used to Edit a Category public CategoryViewModel(Int16 categoryID) { db = new OITaskManagerDataContext(); category = QueryCategory(categoryID); } // Constructor used to Add a Category public CategoryViewModel() { db = new OITaskManagerDataContext(); category = new Category(); } } The code for saving changes: // Don't close window unless all controls are validated if (!vm.IsValid(this)) return; var changes = vm.db.GetChangeSet(); // DEBUG try { vm.db.SubmitChanges(ConflictMode.ContinueOnConflict); } catch (ChangeConflictException) { vm.db.ChangeConflicts.ResolveAll(RefreshMode.KeepChanges); vm.db.SubmitChanges(); } The Xaml (Edited fror brevity): <TextBox Text="{Binding category.CatName, Mode=TwoWay, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}" /> <TextBox Text="{Binding category.CatDescription, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}" /> <CheckBox IsChecked="{Binding category.CatIsInactive, Mode=TwoWay}" /> IssCategory in the Issues table is the old, text based category. This field is no longer used and will be removed from the database as soon as this is working and pushed live.

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  • Using a Button to navigate to another Page in a NavigationWindow

    - by Will
    I'm trying to use the navigation command framework in WPF to navigate between Pages within a WPF application (desktop; not XBAP or Silverlight). I believe I have everything configured correctly, yet its not working. I build and run without errors, I'm not getting any binding errors in the Output window, but my navigation button is disabled. Here's the app.xaml for a sample app: <Application x:Class="Navigation.App" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" StartupUri="First.xaml"> </Application> Note the StartupUri points to First.xaml. First.xaml is a Page. WPF automatically hosts my page in a NavigationWindow. Here's First.xaml: <Page x:Class="Navigation.First" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="First"> <Grid> <Button CommandParameter="/Second.xaml" CommandTarget="{Binding RelativeSource= {RelativeSource FindAncestor, AncestorType={x:Type NavigationWindow}}}" Command="NavigationCommands.GoToPage" Content="Go!"/> </Grid> </Page> The button's CommandTarget is set to the NavigationWindow. The command is GoToPage, and the page is /Second.xaml. I've tried setting the CommandTarget to the containing Page, the CommandParameter to "Second.xaml" (First.xaml and Second.xaml are both in the root of the solution), and I've tried leaving the CommandTarget empty. I've also tried setting the Path to the Binding to various navigational-related public properties on the NavigationWindow. Nothing has worked so far. What am I missing here? I really don't want to do my navigation in code. Clarification. If, instead of using a button, I use a Hyperlink: <Grid> <TextBlock> <Hyperlink NavigateUri="Second.xaml">Go! </Hyperlink> </TextBlock> </Grid> everything works as expected. However, my UI requirements means that using a Hyperlink is right out. I need a big fatty button for people to press. That's why I want to use the button to navigate. I just want to know how I can get the Button to provide the same ability that the Hyperlink does in this case.

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  • Pattern for null settings

    - by user21243
    Hi, I would like to hear your thoughts and ideas about this one. in my application i have controls that are binded to objects properties. but.. the controls always looks like that: a check box, label that explain the settings and then the edited control (for ex: text box) when unchecking the checkbox i disable the text box (using binding) when the checkbox is unchecked i want the property to contain null, and when it is checked i would like the property to contain the text box's text. Of course text box can be NumericUpDown, ComboBox, DatePicker etc.. Do you have any smart way of doing it using binding or do i have to do everything on code; I really would like to a build a control that supports that and re-use it all over Ideas? Thanks,

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  • datagrid column custom check mark

    - by Berryl
    I want a read only column bound to a boolean that shows a check mark image when true and nothing when false. The problem is the false value; I just want to show whatever the background of the datagrid is, but I don't see how to clear the image source. What should the Value of the image source be to do this? Cheers, Berryl <DataGridTemplateColumn.CellTemplate> <DataTemplate> <Image Name="imgChecked" Source="\Img_Checkmark" /> <DataTemplate.Triggers> <DataTrigger Binding="{Binding IsPrimary}" Value="False"> <Setter TargetName="imgChecked" Property="Source" Value=""/> *** ??? *** </DataTrigger> </DataTemplate.Triggers> </DataTemplate> </DataGridTemplateColumn.CellTemplate>

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  • Create slide-in notifications à la Outlook in Windows with .NET

    - by Draak
    I am using .NET and am creating a desktop app/service that will display notifications in the corner of my Desktop when certain events are triggered. I don't want to use a regular Message Box b/c that would be too intrusive. The notifications would slide into view and then fade out after a few seconds. I am thinking of something that will act very much like the Outlook alerts that one gets when a new message arrives. The question is: Should I use WPF for this? I've never done anything with WPF but will happily try it if that's best means to the end. Is there a way to accomplish this with regular .NET libraries?

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  • Using image resource in XAML markup?

    - by Jeff Dahmer
    I'm trying to add little icons to my tabs in WPF but having trouble with how to set up the binding. <TabItem.Header> <StackPanel Orientation="Horizontal"> <Image Source="{Binding Source=prop:Resources.eye}" /> <Label VerticalAlignment="Center">Header</Label> </StackPanel> </TabItem.Header> The xmlns:prop is set up for the local project's Properties, I am pulling other values from it elsewhere so I know that the namespace works. The markup above compiles fine BUT I don't see the eye image in the tab. Also, is there any way to set this up into a template? I'm fairly new to XAML/WPF and each tab will have its own image...

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  • How to implement an ItemsControl3D which can use templates of Visual3D?

    - by Christo
    I'm looking for something like a ContainerUIElement3D which supports the ItemsSource property and an ItemTemplate property which I can use within a Viewport3D. My aim is to be able to write something like: <ItemsControl3D ItemsSource="{Binding Path=MyItems}"> <ItemsControl3D.ItemTemplate> <DataTemplate3D> <!-- My template which defines the binding to each item. --> <DataTemplate3D> </ItemsControl3D.ItemTemplate> </ItemsControl3D> I'm looking for tips on how to implement this. The first tricky part is to create a DataTemplate3D which can construct the Visual3D needed to add to the ItemsControl3D. I've been using .NET reflector to browse through the implementation of ItemsControl and DataTemplate, but I soon realised that I don't have a deep enough understanding and enough time to come up with a solution on my own.

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  • lambda expression for a query on two tables that returns records from one table

    - by peetee
    I have two tables TableA (articles) int id int Type string name and TableB (compatibles) int linked_ID int tableA_ID TableA records: id=1, Type=0, name="ArticleA" id=2, Type=1, name="ArticleB" id=3, Type=2, name="ArticleC" id=4, Type=1, name="ArticleD" TableB records: linked_ID= 1, tableA_ID=2 linked_ID= 1, tableA_ID=3 linked_ID= 1, tableA_ID=4 TableB has a list of arcicels that are compatible to a certain article. I am quite new to queries (didn't need them in my projects yet). But as C# and WPF allow some pretty cool automation with Binding I would like to add a binding that returns the following: Give me all articles that are of Type 1 and compatible to my selected article (id=1). The simple part of it works well (articles has a list of all articles): private ObservableCollection<Article> _articles = new ObservableCollection<Article>(); [fill it with the available articles] and then: comboBoxArticles.ItemsSource = _articles.AsBindable().Where( c => c.Typ == 0 ); How can I extend the Where clause to query another table? Thanks a lot in advance.

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  • Set Validation Tooltip in CodeBehind instead of XAML

    - by KrisTrip
    I would like to know how to translate the following code to codebehind instead of XAML: <Style.Triggers> <Trigger Property="Validation.HasError" Value="true"> <Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource Self}, Path=(Validation.Errors)[0].ErrorContent}"/> </Trigger> </Style.Triggers> The part I can't figure out is the Path portion. I have the following but it doesn't work: new Trigger { Property = Validation.HasErrorProperty, Value = true, Setters = { new Setter { Property = Control.ToolTipProperty, // This part doesn't seem to work Value = new Binding("(Validation.Errors)[0].ErrorContent"){RelativeSource = RelativeSource.Self} } } } Help?

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  • Windows phone app xaml error

    - by thewarri0r9
    i am developing an app for windows phone 8 and i stuck on this code which visual studio showing invalid xaml. But Code compiles and works well. Invalid xaml Code is : <DataTemplate x:Key="AddrBookItemTemplate"> <StackPanel Margin="0,0,0,2" Orientation="Horizontal"> <StackPanel Width="80" Orientation="Horizontal" Height="80"> <Ellipse Margin="0" Height="70" Width="70" HorizontalAlignment="Left" Stroke="{x:Null}"> <Ellipse.Fill> <ImageBrush Stretch="Fill" ImageSource="{Binding imageBytes, Converter={StaticResource BytesToImageConverter}}"/> </Ellipse.Fill> </Ellipse> </StackPanel> <StackPanel Height="80" Margin="0" Width="380" HorizontalAlignment="Left"> <TextBlock FontWeight="Bold" Text="{Binding FirstName}" FontFamily="Segoe WP Semibold" FontSize="30" VerticalAlignment="Top" Margin="5,0,0,0" HorizontalAlignment="Left" /> <TextBlock Text="{Binding Phone}" FontFamily="Segoe WP" FontSize="24" Foreground="{StaticResource PhoneTextBoxReadOnlyBrush}" Margin="5,0,0,-12" Width="320" HorizontalAlignment="Left" VerticalAlignment="Top"/> </StackPanel> </StackPanel> </DataTemplate> I am serializing image by converting it to byte, it works fine but if image is null it gives an error. code behind: if (e.Results != null) { List<AddressBook> source = new List<AddressBook>(); foreach (var result in e.Results) { if (result.PhoneNumbers.FirstOrDefault() != null && result.GetPicture()!=null) { BitmapImage bmp = new BitmapImage(); BitmapImage nullbmp = new BitmapImage(); if (result.GetPicture() == null) { bmp.UriSource = new Uri(@"/Images/ci2.png", UriKind.RelativeOrAbsolute); } else { bmp.SetSource(result.GetPicture()); } listobj.Add(new AddressBook() { FirstName = result.DisplayName != null ? result.DisplayName : "", imageBytes = AddressBook.imageConvert(bmp), EmailAddress = "", LastName = "", Phone = result.PhoneNumbers.FirstOrDefault() != null ? result.PhoneNumbers.FirstOrDefault().PhoneNumber : "", }); } } Above code show an error "object reference not set to instance of an object". I want to show the default image (or color) in ellipse when image is null.What should I do?

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  • Determite when and which a character added or deleted to/from a Text Box.

    - by Alon
    I have a simple text box in a WPF application. I need to know when a character was added/deleted in the text box, which character and where it was added or deleted. I thought to use the TextBox.KeyDown event, but it has some problems: I can't know where the character was added or deleted. I have no idea how to determite which character was added (from the KeyEventArgs). Any ideas? I don't care to use a completely different solution from what I thought. In addition, I've just started this project so I don't care to use Windows Forms instead of WPF if your solution requires it. Thank you.

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  • Proper way to structure a Sync Framework DAL

    - by Refracted Paladin
    I am creating a WPF app that needs to allow users to work in a temporary disconnected state and I plan to use a Local Database Cache. My question's are about my data access layer. Do you typically create the whole DAL to point at the Cache or both and create a switching mechanism? Is Entity's a good way to go for my DAL against the Cache? I am used to L2S but my understanding is that I can't use that against SQLCE, correct? Thanks! PS: Any good resources out there for using Sync, Linq, and WPF ALL TOGETHER? Tutorials, videos, etc?

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  • Determine when and which character is added or deleted in a Text Box.

    - by Alon
    I have a simple text box in a WPF application. I need to know when a character was added/deleted in the text box, which character and where it was added or deleted. I thought to use the TextBox.KeyDown event, but it has some problems: I can't know where the character was added or deleted. I have no idea how to determite which character was added (from the KeyEventArgs). Any ideas? I don't care to use a completely different solution from what I thought. In addition, I've just started this project so I don't care to use Windows Forms instead of WPF if your solution requires it. Thank you.

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  • P-invoke call fails if too much memory is assigned beforehand

    - by RandomEngy
    I've got a p-invoke call to an unmanaged DLL that was failing in my WPF app but not in a simple, starter WPF app. I tried to figure out what the problem was but eventually came to the conclusion that if I assign too much memory before making the call, the call fails. I had two separate blocks of code, both of which would succeed on their own, but that would cause failure if both were run. (They had nothing to do with what the p-invoke call is trying to do). What kind of issues in the unmanaged library would cause such an issue? I thought that the managed and unmanaged heaps were supposed to be automatically separated. The crash as far as I can tell is happening in a dynamically loaded secondary DLL from the one p-invoked into. Could that have something to do with it?

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  • How to save the content of Textbox into a textfile

    - by Owais Wani
    I have a textbox which has some content. I also have a button (SAVE) which shud open the FileSaveDialog and allow the content to be saved in a .txt file. XAML: <TextBox Height="93" IsReadOnly="True" Text="{Binding Path=ReadMessage, Mode=TwoWay}" Name="MessageRead" /> <Button Content="Save" Command="{Binding Path=SaveFileCommand}" Name="I2CSaveBtn" /> ViewModel: private string _readMessage = string.Empty; public string ReadMessage { get { return _readMessage; } set { _readMessage = value; NotifyPropertyChanged("ReadMessage"); } } public static RelayCommand SaveFileCommand { get; set; } private void RegisterCommands() { SaveFileCommand = new RelayCommand(param => this.ExecuteSaveFileDialog()); } private void ExecuteSaveFileDialog() { //What To Do HERE??? } What I basically need is to read the content of textbox, open a file save dialog and store it in a text file to be saved in my system.

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  • WFP Validation & IDataErrorInfo

    - by Jefim
    A note - the classes I have are EntityObject classes! I have the following class: public class Foo { public Bar Bar { get; set; } } public class Bar : IDataErrorInfo { public string Name { get; set; } #region IDataErrorInfo Members string IDataErrorInfo.Error { get { return null; } } string IDataErrorInfo.this[string columnName] { get { if (columnName == "Name") { return "Hello error!"; } Console.WriteLine("Validate: " + columnName); return null; } } #endregion } XAML goes as follows: <StackPanel Orientation="Horizontal" DataContext="{Binding Foo.Bar}"> <TextBox Text="{Binding Path=Name, ValidatesOnDataErrors=true}"/> </StackPanel> I put a breakpoint and a Console.Writeline on the validation there - I get no breaks. The validation is not executed. Can anybody just press me against the place where my error lies?

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  • Setting a property in XAML for a User Control

    - by Ben
    Hi, I have a user control that has a property of type Integer, that i am trying to set in the XAML Template to be that of a property within the bindingsource. If I set the property using a hard coded integer i.e. <MyControl MyIntegerProperty="3" /> This works fine, but if i try <MyControl MyIntegerProperty="{Binding MyDataContextIntegerProperty}" /> it fails. I know that the integer property on MyDataContext is returning a valid integer, and i know that this format works, as directly above this in the template, i have the line <TextBlock Text="{Binding MyDataContextStringProperty}" /> which works correctly. Is there any flag that i need to set on my User Controls Integer property to allow this to work? Or am i doing something else wrong? Thanks

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