Search Results

Search found 9012 results on 361 pages for 'wpf binding'.

Page 66/361 | < Previous Page | 62 63 64 65 66 67 68 69 70 71 72 73  | Next Page >

  • Pass view to viewmodel with datatemplate

    - by jpsstavares
    I have a ParameterView and ParameterViewModel, and I need the ParameterViewModel to have a reference to the Parameter view (more on that later). In the window I have a list of ParameterViewModels and in the ResourceDictionary I add the DataTemplate: <DataTemplate DataType="{x:Type my:ParameterViewModel}" > <my:ParameterView HorizontalAlignment="Left"/> </DataTemplate> I then bind an ItemsControl.ItemSource to the List of ParameterViewModels The problem is: How can I pass the ParameterView to the ParameterViewModel in this scenario? The reason I need the ParameterView in the ParameterViewModel is the following: I have a TextBox whose Text property is binded to the PropertyModelView.Name property. But I want to display a default string when the Name is empty or Null. I've tried to set the property value to the default string I want when that happens but the TextBox.Text is not set in this scenario. I do something like this: private string _name; public string Name { get { return _name; } set { if (value == null || value.Length == 0) Name = _defaultName; else _name = value; } } I've also tried to specifically set the TextBox.Text binding mode to TwoWay without success. I think this is a defense mechanism to prevent an infinite loop from happening but I don't know for sure. Any help on this front would also be highly appreciated. Thanks, José Tavares

    Read the article

  • What does P mean in Sort(Expression<Func<T, P>> expr, ListSortDirection direction)?

    - by Grasshopper
    I am attempting to use the answer in post: How do you sort an EntitySet<T> to expose an interface so that I can sort an EntitySet with a Binding list. I have created the class below and I get the following compiler error: "The type or namespace 'P' could not be found (are you missing a using directive or assembly reference?). Can someone tell me what the P means and which namespace I need to include to get the method below to compile? I am very new to delegates and lamba expressions. Also, can someone confirm that if I create a BindingList from my EntitySet that any modifications I make to the BindingList will be made to the EntitySet? Basically, I have an EntitySet that I need to sort and make changes to. Then, I will need to persist these changes using the original Entity that the BindingList came from. public class EntitySetBindingWrapper<T> : BindingList<T> { public EntitySetBindingWrapper(BindingList<T> root) : base(root) { } public void Sort(Expression<Func<T, P>> expr, ListSortDirection direction) { if (expr == null) base.RemoveSortCore(); MemberExpression propExpr = expr as MemberExpression; if (propExpr == null) throw new ArgumentException("You must provide a property", "expr"); PropertyDescriptorCollection descriptorCol = TypeDescriptor.GetProperties(typeof(T)); IEnumerable<PropertyDescriptor> descriptors = descriptorCol.Cast<PropertyDescriptor>(); PropertyDescriptor descriptor = descriptors.First(pd => pd.Name == propExpr.Member.Name); base.ApplySortCore(descriptor, direction); } }

    Read the article

  • NHibernate Performance Optimization | Suggestions invited!!!

    - by user336749
    Hi, I’m facing an issue with NHibernate performance and can you please suggest me some optimizations? Below mentioned is a small summary of my application architecture I have a windows service which is listening to a messaging bus. On receiving a message the service creates an object out of which a property is the received xml snippet and saves the message to the DB (uses NH). There is a WPF UI with a readonly connection to the DB, and on refresh of the UI it displays the objects on the screen. While the UI does a refresh, it retrieves the xml and deserializes it , from which the object’s properties are derived and binded to the screen. For example assume an xml XXX is received by the service, it deserializes the xml , creates the book object and save it to the DB and a property/column is SCHEMA which contains the xml snippet. The UI while refreshed searches all book objects by ID and creates the book objects out of the xml which is being saved (yes, the xml is the constructor param). Now my issue is that the refresh takes more than 2 minutes to display say 50 book objects. I analyzed it using the NHibernate profiler, and found that the time spend within the DB is negligible, however time spent to create the entities is proportionally huge(10ms:1990 ms).I guess it’s due to the fairly huge size of xml snippet and it’s deserialization. My question is, how can I improve the performance. I dispose sessions after every refresh and is not lazy loading (please note that the time spend in DB is negligible). On every refresh it’s possible that all objects are updated by some downstream systems or maybe one of them are updated.Can I implement some sort of caching mechanism in this case? Thanks in advance for any suggestions. Regards, -Mike

    Read the article

  • Linq To SQL: Behaviour for table field which is NotNull and having Default value or binding

    - by kaushalparik27
    I found this something interesting while wandering over community which I would like to share. The post is whole about: DBML is not considering the table field's "Default value or Binding" setting which is a NotNull. I mean the field which can not be null but having default value set needs to be set IsDbGenerated = true in DBML file explicitly.Consider this situation: There is a simple tblEmployee table with below structure: The fields are simple. EmployeeID is a Primary Key with Identity Specification = True with Identity Seed = 1 to autogenerate numeric value for this field. EmployeeName and their EmailAddress to store in rest of 2 fields. And the last one is "DateAdded" with DateTime datatype which doesn't allow NULL but having Default Value/Binding with "GetDate()". That means if we don't pass any value to this field then SQL will insert current date in "DateAdded" field.So, I start with a new website, add a DBML file and dropped the said table to generate LINQ To SQL context class. Finally, I write a simple code snippet to insert data into the tblEmployee table; BUT, I am not passing any value to "DateAdded" field. Because I am considering SQL Server's "Default Value or Binding (GetDate())" setting to this field and understand that SQL will insert current date to this field.        using (TestDatabaseDataContext context = new TestDatabaseDataContext())        {            tblEmployee tblEmpObjet = new tblEmployee();            tblEmpObjet.EmployeeName = "KaushaL";            tblEmpObjet.EmployeeEmailAddress = "[email protected]";            context.tblEmployees.InsertOnSubmit(tblEmpObjet);            context.SubmitChanges();        }Here comes the twist when application give me below error:  This is something not expecting! From the error it clearly depicts that LINQ is passing NULL value to "DateAdded" Field while according to my understanding it should respect Sql Server's "Default value or Binding" setting for this field. A bit googling and I found very interesting related to this problem.When we set Primary Key to any field with "Identity Specification" Property set to true; DBML set one important property "IsDbGenerated=true" for this field. BUT, when we set "Default Value or Biding" property for some field; we need to explicitly tell the DBML/LINQ to let it know that this field is having default binding at DB side that needs to be respected if I don't pass any value. So, the solution is: You need to explicitly set "IsDbGenerated=true" for such field to tell the LINQ that the field is having default value or binding at Sql Server side so, please don't worry if i don't pass any value for it.You can select the field and set this property from property window in DBML Designer file or write the property in DBML.Designer.cs file directly. I have attached a working example with required table script with this post here. I hope this would be helpful for someone hunting for the same. Happy Discovery!

    Read the article

  • Silverlight Binding with multiple collections

    - by George Evjen
    We're designing some sport specific applications. In one of our views we have a gridview that is bound to an observable collection of Teams. This is pretty straight forward in terms of getting Teams bound to the GridView. <telerik:RadGridView Grid.Row="0" Grid.Column="0" x:Name="UsersGrid" ItemsSource="{Binding TeamResults}" SelectedItem="{Binding SelectedTeam, Mode=TwoWay}"> <telerik:RadGridView.Columns> <telerik:GridViewDataColumn Header="Name/Group" DataMemberBinding="{Binding TeamName}" MinWidth="150"></telerik:GridViewDataColumn> </telerik:RadGridView.Columns> </telerik:RadGridView> We use the observable collection of teams as our items source and then bind the property of TeamName to the first column. You can set the binding to mode=TwoWay, we use a dialog where we edit the selected item, so our binding here is not set to two way. The issue comes when we want to bind to a property that has another collection in it. To continue on our code from above, we have an observable collection of teams, within that collection we have a collection of KeyPeople. We get this collection using RIA Serivces with the code below. return _TeamsRepository.All().Include("KeyPerson"); Here we are getting all the teams and also including the KeyPerson entity. So when we are done with our Load we will end up with an observable collection of Teams with a navigation property / entity of KeyPerson. Within this KeyPerson entity is a list of people associated with that particular team. We want to display the head coach from this list of KeyPersons. This list currently has a list of ten or more people that are bound to this team, but we just want to display the Head Coach in the column next to team name. The issue becomes how do we bind to this included entity? I have found about three different ways to solve this issue. The way that seemed to fit us best is to utilize the features within RIA Services. We can create client side properties that will do the work for us. We will create in the client side library a partial class of Team. We will end up in our library a file that is Team.shared.cs. The code below is what we will put into our partial team class. public KeyPerson Coach        {            get            {                if (this.KeyPerson != null && this.KeyPerson.Any())                { return this.KeyPerson.Where(x => x.RelationshipType == “HeadCoach”).FirstOrDefault(); }                 return null;            }        } We will return just the person that is the Head Coach and then be able to bind that and any other additional properties that we need. <telerik:GridViewDataColumn Header="Coach" DataMemberBinding="{Binding Coach.Name}" MinWidth="150"></telerik:GridViewDataColumn> There are other ways that we could have solved this issue but we felt that creating a partial class through RIA Services best suited our needs.

    Read the article

  • WPF CheckBox style with the TextWrapping

    - by Shurup
    I need you a TextWrapping in the WPF CheckBox. Please look at this two samples: <CheckBox> <TextBlock TextWrapping="Wrap" Text="_This is a long piece of text attached to a checkbox."/> </CheckBox> <CheckBox> <AccessText TextWrapping="Wrap" Text="_This is a long piece of text attached to a checkbox."/> </CheckBox> If I use a TextBlock in the Content of the CheckBox, the check element (vertical alignment is top) and the text displays properly, but not the accelerator. If I use an AccessText in the Content of the CheckBox, the check element displays wrong (vertical alignment is center). How to change the style of the elements to display this CheckBox correct?

    Read the article

  • WPF TreeView databinding to hide/show expand/collapse icon

    - by Julian Lettner
    I implemented a WPF load-on-demand treeview like described in this (very good) article. In the mentioned solution a dummy element is used to preserve the expand + icon / treeview item behavior. The dummy item is replaced with real data, when the user clicks on the expander. I want to refine the model by adding a property public bool HasChildren { get { ... } } to my backing TreeNodeViewModel. Question: How can I bind this property to hide/show the expand icon (in XAML)? I am not able to find a suitable trigger/setter combination. (INotifyPropertyChanged is properly implemented.) Thanks for your time. Update 1: I want to use my property public bool HasChildren instead of using the dummy element. Determining whether or not an item has children is somewhat costly, but still much cheaper than fetching the children.

    Read the article

  • WPF ListView ScrollViewer Double-Click Event

    - by Sentax
    Doing the below will reproduce my problem: New WPF Project Add ListView Name the listview: x:Name="lvList" Add enough ListViewItems to the ListView to fill the list completely so a vertical scroll-bar appears during run-time. Put this code in the lvList.MouseDoubleClick event Debug.Print("Double-Click happened") Run the application Double-click on the LargeChange area of the scroll-bar (Not the scroll "bar" itself) Notice the Immediate window printing the double-click happened message for the ListView How do I change this behavior so MouseDoubleClick only happens when the mouse is "over" the ListViewItems and not when continually clicking the ScrollViewer to scroll down/up in the list?

    Read the article

  • WPF WebBrowser NavigateToString vs NavigateToStream (hebrew/non-utf8 encodings)

    - by David E
    When I use WPF WebBrowser's NavigateToString method to display UTF8 html (with hebrew text in it) it's displayed perfectly. However, when I try to use the NavigateToString to display html with hebrew text in it in a non-utf8 encoding (CodePage 1255 to be exact) the hebrew is messed up. I checked the cp1255 string in Visual Studio's debugger and it looks great, and also when I save the source of the web browser's contents and open it with an external browser it looks great. If I use the NavigateToStream method instead of the NavigateToString method it works great. What's the problem with the NavigateToString? am I doing something wrong?

    Read the article

  • WPF - Pan & Zoom Image

    - by Yuval Peled
    I want to create a simple image viewer in WPF that will enable the user to: Pan (by mouse dragging the image). Zoom (with a slider). Show overlays (rectangle selection for example). Show original image (with scroll bars if needed). Can you explain how to do it? I didn't find a good sample on the web. Should I use ViewBox? Or ImageBrush? Do I need ScrollViewer? Thanks!

    Read the article

  • Paste Event in a WPF TextBox

    - by code-zoop
    I have created a custom control inheriting TextBox. This custom control is a numeric TextBox, only supporting numbers. I am using OnPreviewTextInput to check each new character being typed to see if the character is a valid input. This works great. However, if I paste the text into the TextBox, OnPreviewTextInput is not fired. What is the best way to capture pasted text in a TextBox? Also, I have a problem when the back space is pressed, I can't figure out what event this will fire. OnPreviewTextInput is not fired! any ideas how to capture pasted text and back space events in WPF TextBox? Thanks

    Read the article

  • Setting a WPF ContextMenu's PlacementTarget property in XAML?

    - by qntmfred
    <Button Name="btnFoo" Content="Foo" > <Button.ContextMenu Placement="Bottom" PlacementTarget="btnFoo"> <MenuItem Header="Bar" /> </Button.ContextMenu> </Button> gives me a runtime error 'UIElement' type does not have a public TypeConverter class I also tried <Button Name="btnFoo" Content="Foo" > <Button.ContextMenu Placement="Bottom" PlacementTarget="{Binding ElementName=btnFoo}"> <MenuItem Header="Bar" /> </Button.ContextMenu> </Button> and that put the ContextMenu in the top left corner of my screen, rather than at the Button

    Read the article

  • WPF: Filter TreeView without collapsing it's nodes

    - by Julian Lettner
    This one is a follow-up question. I filter the top level nodes of a TreeView control like shown below. private void ApplyFilterHandler(object sender, RoutedEventArgs e) { if (_filterCheckBox.IsChecked.Value) CollectionViewSource.GetDefaultView(TopLevelNodes).Filter += MyFilter; else CollectionViewSource.GetDefaultView(TopLevelNodes).Filter -= MyFilter; } . <TreeView ItemsSource="{Binding TopLevelNodes}"> ... </TreeView> When the user applies the filter all nodes get collapsed. Question How can I hide certain nodes in a tree while retaining the expand state of the other nodes? Can someone explain, what happens internally on ICollectionView.Filter += MyFilter. Thanks for your time.

    Read the article

  • How to make WPF DataGrid Column Header transparent

    - by joerage
    Hi, I am trying to make the column header of my WPF Datagrid to be transparent. I am able to set it to a color without problem, but I can't have it transparent. Here is what I tried: <Style x:Key="DatagridColumnHeaderStyle" TargetType="{x:Type tk:DataGridColumnHeader}"> <Setter Property="Background" Value="Transparent" /> <Setter Property="Foreground" Value="#C2C4C6" /> </Style> <Style x:Key="DashboardGridStyle" TargetType="{x:Type tk:DataGrid}"> <Setter Property="ColumnHeaderStyle" Value="{StaticResource DatagridColumnHeaderStyle}" /> <Setter Property="Background" Value="Transparent" /> <Setter Property="RowBackground" Value="Transparent" /> </Style> <tk:DataGrid Style="{StaticResource DashboardGridStyle}" > ... </tk:DataGrid> With this code, it seems to take the default brush. What am I missing?

    Read the article

  • WPF HwndHost keyboard focus

    - by Adal
    The chart area in the screenshot is a HwndHost control which hosts a native Win32 window (with it's own registered WNDCLASS) implemented in C++/CLI and drawn with Direct2D. The HwndHost is hosted in a WPF Border control. The problem I have is that I can't set the keyboard focus to the hosted Win32 window. I want the focus to move to the hosted Win32 window when the used clicks on the chart area. I tried calling SetFocus on WM_LBUTTONDOWN, but that screws app the focus in the rest of the application. Currently, even if I click on the Win32 window, the focus remains on the tree-view on the left, and if I press the up/down cursor keys, the tree-view will get them, not the chart window. How do I make the hosted Win32 window receive keyboard input from when the user clicks on the chart area, until it clicks on another control (like the tree-view, or the toolbar)?

    Read the article

  • Rendering WPF DrawingGroup to single ImageSource

    - by Xander
    Currently I'm using a System.Windows.Media.DrawingGroup to store some tiled images (ImageDrawing) inside the Children-DrawingCollection property. Well the problem is now, this method gets really slow if you display the entire DrawingGroup in an Image control, because my DrawingGroup can contain hundreds or even thousands of small images it can really mess up the performance. So my first thought was to somehow render a single image from all the small ones inside the DrawingGroup and then only display that image, that would be much faster. But as you might have figured out I haven't found any solution so simply combine several images with WPF Imaging. It would really be great if someone could help with this problem or tell me how i can improve the performance with the DrawingGroup or even use another approach. One last thing, currently I'm using a RenderTargetBitmap to generate a single BitmapSource from the DrawingGroup, this approach isn't really faster, but it makes the scrolling and working on the Image control at least a little smoother.

    Read the article

  • WPF FlowDocument - Absolute Character Position

    - by Alan Spark
    I have a WPF RichTextBox that I am typing some text into and then parsing the whole of the text to do processing on. During this parse, I have the absolute character positions of the start and end of each word. I would like to use these character positions to apply formatting to certain words. However, I have discovered that the FlowDocument uses TextPointer instances to mark positions in the document. I have found that I can create a TextRange by constructing it with start and end pointers. Once I have the TextRange I can easily apply formatting to the text within it. I have been using GetPositionAtOffset to get a TextPointer for my character offset but suspect that its offset is different from mine because the selected text is in a slightly different position from what I expect. My question is, how can I accurately convert an absolute character position to a TextPointer?

    Read the article

  • WPF Frame accessing parent page controls

    - by Mitch
    I have a WPF page that contains a Listbox and a frame. The frame has various pages loaded into it determined by the selection within the Listbox. Each page within the frame has a variety of different input boxes and has a Save Cancel button. When the Save button is clicked I need the content to be saved to the database and the Listbox in the parent page to be refreshed to reflect the new data. Saving the data is easy but how do I initiate a refresh on the contents of the Listbox in the parent page when calling it from the page that inside the frame? I need to somehow be able to access the parent pages controls to do this. Any ideas?

    Read the article

  • WPF, PreviewKeyDown event and underscore char

    - by commanderz
    Hi, I'm catching key hits with PreviewKeyDown event in my WPF component. I need to distinguish characters being typed: letters vs. numbers vs. underscore vs. anything else. Letters and numbers work fine (just convert the Key property of the KeyEventArgs object to string and work with character 0 of that string), but this won't work for underscore. It's ToString value depends on localized keyboard settings (it shows up as "OemMinus" on EN/US keyboard and "OemQuestion" on CZ/QWERTY keyboard). So how can I RELIABLY find out, if the typed char is underscore in the PreviewKeyDown event? Thanks for any help

    Read the article

  • C# / WPF / .NET - Drag and drop to Desktop / Explorer

    - by Dänu
    Hey Guys Following my scenario. I got an Application which loads a Filestructure (Folders, Files) from a Database into a WPF ListView. Now I'd like to grab a file from this ListView, drag it over my Desktop (or some open explorer window) and drop it there. Basic Drag and Drop, nothing fancy. This sounds like a "standard" function for a windows application - but google won't help. So how can I achieve this? Interops? Thanks Edit: Thanks for the solution, I still had to do some googling. Here's my complete solution.

    Read the article

  • WPF TextBlock highlight certan parts based on search condition

    - by Daniil Harik
    Hello, I have TextBlock that has Inlines dynamicly added to it (basically bunch of Run objects that are either italic or bold). In my application I have search function. I want to be able to highlight TextBlock's text that is in being searched for. By highlighting I mean changing certain parts of TextBlock text's color (keeping in mind that it may highlight several different Run objects at a time). I have tried this example http://blogs.microsoft.co.il/blogs/tamir/archive/2008/05/12/search-and-highlight-any-text-on-wpf-rendered-page.aspx But it seams very unstable :( Is there easy way to solve this problem?

    Read the article

  • WPF ShowDialog returns immediately

    - by dthrasher
    Sometimes when I call ShowDialog on an OpenFileDialog Window in WPF, the dialog closes immediately with a return value of false. I'm calling ShowDialog in response to a button click event. I can reproduce this problem using the sample code for OpenFileDialog on MSDN: // Configure open file dialog box Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog(); dlg.FileName = "Document"; // Default file name dlg.DefaultExt = ".txt"; // Default file extension dlg.Filter = "Text documents (.txt)|*.txt"; // Filter files by extension // Show open file dialog box Nullable<bool> result = dlg.ShowDialog(); // Process open file dialog box results if (result == true) { // Open document string filename = dlg.FileName; } The problem occurs intermittently when I run my solution in Debug mode from Visual Studio 2008 SP1. It's quite annoying. Is this a known issue? Are there workarounds?

    Read the article

  • Disable selecting in WPF DataGrid

    - by svick
    How can I disable selecting in a WPFTooklit's DataGrid? I tried modifying the solution that works for ListView (from http://stackoverflow.com/questions/1051215/wpf-listview-turn-off-selection#comment-863179), but that doesn't work: <tk:DataGrid> <tk:DataGrid.ItemContainerStyle> <Style TargetType="{x:Type tk:DataGridRow}"> <Setter Property="Focusable" Value="false"/> </Style> </tk:DataGrid.ItemContainerStyle> <tk:DataGrid.CellStyle> <Style TargetType="{x:Type tk:DataGridCell}"> <Setter Property="Focusable" Value="false"/> </Style> </tk:DataGrid.CellStyle> </tk:DataGrid>

    Read the article

  • WPF DataGrid Printing Scrolled Visuals

    - by RichS
    I've been using the DataGrid (from WPF Toolkit), and have successfully created all of my data. The next step is that I want to print the entire DataGrid (scaled to a single printed page), even though the visible DataGrid in my Window is currently scrolled. When I prepare the DataGrid for printing, I've tried setting the DesiredSize to PositiveInfinity, and then calling Measure(.), to get the needed size of the DataGrid. But, when I call Arrange(.), it only prints the part of the DataGrid control that is currently visible on-screen. I know how to scale it to the correct size, but can't get the non-visible part of the DataGrid to be output to the printer. I've tried rendering to a Bitmap (RenderTargetBitmap), but that has the same problem. I also tried setting the MinHeight and MinWidth to be the same as the DesiredSize to try to /force/ things. But that doesn't work either. All I ever see in my printed page, is what was visible on-screen. Does anyone know how to solve this?

    Read the article

  • WPF Blurry Images - Bitmap Class

    - by Luke
    I am using the following sample at http://blogs.msdn.com/dwayneneed/archive/2007/10/05/blurry-bitmaps.aspx within VB.NET. The code is shown below. I am having a problem when my application loads the CPU is pegging 50-70%. I have determined that the problem is with the Bitmap class. The OnLayoutUpdated() method is calling the InvalidateVisual() continously. This is because some points are not returning as equal but rather, Point(0.0,-0.5) Can anyone see any bugs within this code or know a better implmentation for pixel snapping a Bitmap image so it is not blurry? p.s. The sample code was in C#, however I believe that it was converted correctly. Imports System Imports System.Collections.Generic Imports System.Windows Imports System.Windows.Media Imports System.Windows.Media.Imaging Class Bitmap Inherits FrameworkElement ' Use FrameworkElement instead of UIElement so Data Binding works as expected Private _sourceDownloaded As EventHandler Private _sourceFailed As EventHandler(Of ExceptionEventArgs) Private _pixelOffset As Windows.Point Public Sub New() _sourceDownloaded = New EventHandler(AddressOf OnSourceDownloaded) _sourceFailed = New EventHandler(Of ExceptionEventArgs)(AddressOf OnSourceFailed) AddHandler LayoutUpdated, AddressOf OnLayoutUpdated End Sub Public Shared ReadOnly SourceProperty As DependencyProperty = DependencyProperty.Register("Source", GetType(BitmapSource), GetType(Bitmap), New FrameworkPropertyMetadata(Nothing, FrameworkPropertyMetadataOptions.AffectsRender Or FrameworkPropertyMetadataOptions.AffectsMeasure, New PropertyChangedCallback(AddressOf Bitmap.OnSourceChanged))) Public Property Source() As BitmapSource Get Return DirectCast(GetValue(SourceProperty), BitmapSource) End Get Set(ByVal value As BitmapSource) SetValue(SourceProperty, value) End Set End Property Public Shared Function FindParentWindow(ByVal child As DependencyObject) As Window Dim parent As DependencyObject = VisualTreeHelper.GetParent(child) 'Check if this is the end of the tree If parent Is Nothing Then Return Nothing End If Dim parentWindow As Window = TryCast(parent, Window) If parentWindow IsNot Nothing Then Return parentWindow Else ' Use recursion until it reaches a Window Return FindParentWindow(parent) End If End Function Public Event BitmapFailed As EventHandler(Of ExceptionEventArgs) ' Return our measure size to be the size needed to display the bitmap pixels. ' ' Use MeasureOverride instead of MeasureCore so Data Binding works as expected. ' Protected Overloads Overrides Function MeasureCore(ByVal availableSize As Size) As Size Protected Overloads Overrides Function MeasureOverride(ByVal availableSize As Size) As Size Dim measureSize As New Size() Dim bitmapSource As BitmapSource = Source If bitmapSource IsNot Nothing Then Dim ps As PresentationSource = PresentationSource.FromVisual(Me) If Me.VisualParent IsNot Nothing Then Dim window As Window = window.GetWindow(Me.VisualParent) If window IsNot Nothing Then ps = PresentationSource.FromVisual(window.GetWindow(Me.VisualParent)) ElseIf FindParentWindow(Me) IsNot Nothing Then ps = PresentationSource.FromVisual(FindParentWindow(Me)) End If End If ' If ps IsNot Nothing Then Dim fromDevice As Matrix = ps.CompositionTarget.TransformFromDevice Dim pixelSize As New Vector(bitmapSource.PixelWidth, bitmapSource.PixelHeight) Dim measureSizeV As Vector = fromDevice.Transform(pixelSize) measureSize = New Size(measureSizeV.X, measureSizeV.Y) Else measureSize = New Size(bitmapSource.PixelWidth, bitmapSource.PixelHeight) End If End If Return measureSize End Function Protected Overloads Overrides Sub OnRender(ByVal dc As DrawingContext) Dim bitmapSource As BitmapSource = Me.Source If bitmapSource IsNot Nothing Then _pixelOffset = GetPixelOffset() ' Render the bitmap offset by the needed amount to align to pixels. dc.DrawImage(bitmapSource, New Rect(_pixelOffset, DesiredSize)) End If End Sub Private Shared Sub OnSourceChanged(ByVal d As DependencyObject, ByVal e As DependencyPropertyChangedEventArgs) Dim bitmap As Bitmap = DirectCast(d, Bitmap) Dim oldValue As BitmapSource = DirectCast(e.OldValue, BitmapSource) Dim newValue As BitmapSource = DirectCast(e.NewValue, BitmapSource) If ((oldValue IsNot Nothing) AndAlso (bitmap._sourceDownloaded IsNot Nothing)) AndAlso (Not oldValue.IsFrozen AndAlso (TypeOf oldValue Is BitmapSource)) Then RemoveHandler DirectCast(oldValue, BitmapSource).DownloadCompleted, bitmap._sourceDownloaded RemoveHandler DirectCast(oldValue, BitmapSource).DownloadFailed, bitmap._sourceFailed ' ((BitmapSource)newValue).DecodeFailed -= bitmap._sourceFailed; // 3.5 End If If ((newValue IsNot Nothing) AndAlso (TypeOf newValue Is BitmapSource)) AndAlso Not newValue.IsFrozen Then AddHandler DirectCast(newValue, BitmapSource).DownloadCompleted, bitmap._sourceDownloaded AddHandler DirectCast(newValue, BitmapSource).DownloadFailed, bitmap._sourceFailed ' ((BitmapSource)newValue).DecodeFailed += bitmap._sourceFailed; // 3.5 End If End Sub Private Sub OnSourceDownloaded(ByVal sender As Object, ByVal e As EventArgs) InvalidateMeasure() InvalidateVisual() End Sub Private Sub OnSourceFailed(ByVal sender As Object, ByVal e As ExceptionEventArgs) Source = Nothing ' setting a local value seems scetchy... RaiseEvent BitmapFailed(Me, e) End Sub Private Sub OnLayoutUpdated(ByVal sender As Object, ByVal e As EventArgs) ' This event just means that layout happened somewhere. However, this is ' what we need since layout anywhere could affect our pixel positioning. Dim pixelOffset As Windows.Point = GetPixelOffset() If Not AreClose(pixelOffset, _pixelOffset) Then InvalidateVisual() End If End Sub ' Gets the matrix that will convert a Windows.Point from "above" the ' coordinate space of a visual into the the coordinate space ' "below" the visual. Private Function GetVisualTransform(ByVal v As Visual) As Matrix If v IsNot Nothing Then Dim m As Matrix = Matrix.Identity Dim transform As Transform = VisualTreeHelper.GetTransform(v) If transform IsNot Nothing Then Dim cm As Matrix = transform.Value m = Matrix.Multiply(m, cm) End If Dim offset As Vector = VisualTreeHelper.GetOffset(v) m.Translate(offset.X, offset.Y) Return m End If Return Matrix.Identity End Function Private Function TryApplyVisualTransform(ByVal Point As Windows.Point, ByVal v As Visual, ByVal inverse As Boolean, ByVal throwOnError As Boolean, ByRef success As Boolean) As Windows.Point success = True If v IsNot Nothing Then Dim visualTransform As Matrix = GetVisualTransform(v) If inverse Then If Not throwOnError AndAlso Not visualTransform.HasInverse Then success = False Return New Windows.Point(0, 0) End If visualTransform.Invert() End If Point = visualTransform.Transform(Point) End If Return Point End Function Private Function ApplyVisualTransform(ByVal Point As Windows.Point, ByVal v As Visual, ByVal inverse As Boolean) As Windows.Point Dim success As Boolean = True Return TryApplyVisualTransform(Point, v, inverse, True, success) End Function Private Function GetPixelOffset() As Windows.Point Dim pixelOffset As New Windows.Point() Dim ps As PresentationSource = PresentationSource.FromVisual(Me) If ps IsNot Nothing Then Dim rootVisual As Visual = ps.RootVisual ' Transform (0,0) from this element up to pixels. pixelOffset = Me.TransformToAncestor(rootVisual).Transform(pixelOffset) pixelOffset = ApplyVisualTransform(pixelOffset, rootVisual, False) pixelOffset = ps.CompositionTarget.TransformToDevice.Transform(pixelOffset) ' Round the origin to the nearest whole pixel. pixelOffset.X = Math.Round(pixelOffset.X) pixelOffset.Y = Math.Round(pixelOffset.Y) ' Transform the whole-pixel back to this element. pixelOffset = ps.CompositionTarget.TransformFromDevice.Transform(pixelOffset) pixelOffset = ApplyVisualTransform(pixelOffset, rootVisual, True) pixelOffset = rootVisual.TransformToDescendant(Me).Transform(pixelOffset) End If Return pixelOffset End Function Private Function AreClose(ByVal Point1 As Windows.Point, ByVal Point2 As Windows.Point) As Boolean Return AreClose(Point1.X, Point2.X) AndAlso AreClose(Point1.Y, Point2.Y) End Function Private Function AreClose(ByVal value1 As Double, ByVal value2 As Double) As Boolean If value1 = value2 Then Return True End If Dim delta As Double = value1 - value2 Return ((delta < 0.00000153) AndAlso (delta > -0.00000153)) End Function End Class

    Read the article

< Previous Page | 62 63 64 65 66 67 68 69 70 71 72 73  | Next Page >