I have a 3rd party control (Visifire) which has a namespace that uses the "." format. This works fine in a WPF application, but not in a UserControl as it generates a "can't find assembly" if you try to include the namespace. This means I have to use code to add the control, set up the bindings, etc, etc, which is quite annoying as I would prefer to use XAML.
My thought was to trick the UserControl using the following:
namespace MyControl
{
public class MyChart : Visifire.Charts.Chart
{
public MyChart () : base() {}
}
public partial Chart : UserControl
{
// All the control stuff goes here
}
}
Then, in XAML, I would use:
xmlns:local="clr-namespace:MyControl"
<Grid>
<local:MyChart>
</local:MyChart>
</Grid>
This doesn't seem to work, as it generates an exception.
Anybody have any tips on how I could get around this? THanks much!
You can use:
<Grid xmlns:charts="clr-namespace:Visifire.Charts;assembly=Visifire">
<charts:Chart>...</charts:Chart>
</Grid>
To import a fully-qualified namespace, does that not work for you?
Related
I have several WPF UserControls. Each of these controls implement an interface IStepEditor
The class declaration is as follow:
public partial class EditorLoadCsv : UserControl, IStepEditor { ... }
IStepEditor is not very important, but it is currently defined as follow:
public interface IStepEditor
{
StepConfig Save();
void Load(StepConfig config);
}
I then have several classes holding those controls, like this:
public class StepConfigController
{
public IStepEditor EditorControl { get; }
}
All of this is working as expected when I use IStepEditor all around, but to add those controls to a WPF window from a StepConfigController, I eventually have to cast them in a UserControl, like this:
((StackPanel)panEditorControl).Children.Add(currentControl as UserControl);
Since the IStepEditor implementation is actually a UserControl, it works. I could add checks for that cast, but the whole idea seems wrong. I cast an object to another very unrelated object through some weak relationship I trust others to follow.
I tried to create an abstract class inheriting from both UserControl and IStepEditor and have my actual UserControls derive from that, but since the WPF UserControls are partial classes, it didn't work. It was something like this:
public abstract class StepEditorControl : UserControl, IStepEditor
{
abstract public StepConfig Save();
abstract public Load(StepConfig config);
}
So this class was legit and compiled, but trying to derive from it in WPF failed.
public partial class EditorLoadCsv : StepEditorControl
{
}
This code generates:
error CS0263: Partial declarations of 'EditorLoadCsv' must not specify different base classes
Which is right, because the xaml markup still references a UserControl. Trying to change the xaml markups from UserControl to a StepEditorControl failed, but it could be the proper solution to the whole problem. I also tried to implement a WPF Custom Control Library, but it seemed like a lot of work just to implement an interface with 2 methods.
The XAML is generated automagically through Visual Studio designer:
<UserControl x:Class="MyNamespace.EditorLoadCsv"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:MyNamespace"
mc:Ignorable="d"
d:DesignHeight="50" d:DesignWidth="623.077">
<!--- Actual UserControl content ---!>
</UserControl>
So an answer to either of these questions could solve my problem:
1- How to avoid a (possibly) dangerous dynamic cast when implementing WPF UserControl with custom interfaces?
2- How to get WPF XAML markup to accept a custom class instead of UserControl?
3- How to refactor code to avoid this ugliness in the first place?
The Panel.Children property is a UIElementCollection, so anything that should be added needs to be a UIElement, which is the base class of all WPF UI components.
Do not use the as operator, but simply cast your editor objects to UIElement. If any of them is by accident not a UIElement, you would correctly get an InvalidCastException.
((Panel)panEditorControl).Children.Add((UIElement)currentControl);
In order to create a UserControl-derived base class for all your StepEditors, you did the first step correctly:
public abstract class StepEditorControl : UserControl, IStepEditor
{
public abstract void Load(StepConfig config);
public abstract StepConfig Save();
}
However, the XAML of a control derived from StepEditorControl would have to look like this:
<local:StepEditorControl
x:Class="MyNamespace.EditorLoadCsv"
xmlns:local="clr-namespace:MyNamespace"
...>
...
</local:StepEditorControl>
I have a XAML MyXamlStyleSheet.xaml where I define the style of a Button and Various other Controls.
I also have a C# class MyButtonClass : Button that I defined to intercept the basic Button class and declare any custom functionality that I want to give it.
In the XAML Window where I want to use I have declared a xmlns:lc with the source pointing to the C# class MyButtonClass.
What I want to do is that when I declare this custom button
<lc:MyButtonClass .../>
I have a Reference to the Style defined in MyXamlStyleSheet that is stored in MyButtonClass so that I can access it from the XAML Window.
What would I write in the class and in the xaml declaration?
<lc:MyButtonClass Style="{StaticResource ???"..../>
Until now I have used MergedDictionaries to reference the XAML style sheet directly. However I want to do it using this different path.
Found the answer. It´s the same as Merging a Dictionary to your XAML Window int the Window.Resources section. From your class you instantiate a ResourceDictionary with the correct path and Merge that dictionary to the Dictionary of the Button class.
namespace YourNamespace
{
public class MyCustomButton : Button
{
public MyCostumButton()
{
ResourceDictionary res = Application.LoadComponent(new Uri("/Directory/StyleDirectory.xaml", UriKind.RelativeOrAbsolute)) as ResourceDictionary;
if (res == null)
return;
Resources.MergedDictionaries.Add(res);
Style = (Style)FindResource("Name of the x:Key your gave your style");
}
}
}
This let´s you write an entire library of standarized controls in a Folder, where each control has a C# class assigned to it. So if you have many implementations of the same control you can always define the most basic behaviour and look in the XAML file that the class is referencing.
I am fairly new to WPF and I am having a problem with inheriting from a user control.
I created a User Control and now I need to inherit from that control and add some more functionality.
Has anyone does this sort of thing before? Any help would be greatly appreciated.
Thank you
Well .. you create your base control
public abstract class BaseUserControl : UserControl{...}
then in the XAML file :
<Controls:BaseUserControl x:Class="Termo.Win.Controls.ChildControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:Controls="clr-namespace:Namespace.Of.Your.BaseControl">
And that should work.
EDIT: Hmm.. this example is useful when you have a base control without XAML and then inherit from it. The other way around(from a base control with Xaml) - I'm not sure how you can go about it.
EDIT2: Apparently from this post + comments i take that what you want might not be possible.
AFAIK you cannot inherit the xaml, you can only inherit the code behind.
We recently encountered the same problem on our project. The way we ended up solving our problem was to create a usercontrol and adding it to the "child" usercontrol.
If that doesnt work/help take a look at this:
https://web.archive.org/web/20200815091447/http://geekswithblogs.net/lbugnion/archive/2007/03/02/107747.aspx[1]
I may have a bit of a solution: Composition instead of inheritance - I have come up with control, that has 'content slots' assignable from outside through databinding, look at my SO thread.
Example of use:
<UserControl ... >
<!-- My wrapping XAML -->
<Common:DialogControl>
<Common:DialogControl.Heading>
<!-- Slot for a string -->
</Common:DialogControl.Heading>
<Common:DialogControl.Control>
<!-- Concrete dialog's content goes here -->
</Common:DialogControl.Control>
<Common:DialogControl.Buttons>
<!-- Concrete dialog's buttons go here -->
</Common:DialogControl.Buttons>
</Common:DialogControl>
<!-- /My wrapping XAML -->
</UserControl>
Together with some handling code in codebehind it would be a nice base component for dialog windows.
You cannot inherit the xaml code it self. However creating an abstract class of the codebehind, will allow you to edit in code behind, from a derived class object.
Xaml Code: { Window1.xaml }
<Window
x:Class="WPFSamples.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Height="auto" Width="256" Title="WPF Sameples">
<Grid>
<Button x:Name="Button1" VerticalAlignment="Center" HorizontalAlignment="Center" Content="Click Me"/>
</Grid>
</Window>
CodeBehind: { Window1.xaml.cs }
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace WPFSamples
{
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public abstract partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
}
}
}
Derived Class : { DisabledButtonWindow.cs }
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace WPFSamples
{
public sealed class DisabledButtonWindow : Window1
{
public DisabledButtonWindow()
{
Button1.IsEnabled = false;
}
}
}
although you cannot inherit from the wpf source it self, you are able to use this "Window1" control as a template for all other derived controls.
You can accomplish this by using a delegate.
Essentially, you need to create an interface (YourInterface) which wraps up the functionality you want, then make both the user control and your class implement that interface.
Next, make sure the user control has a reference to an object of type IYourInterface, so that when your user control attempts to invoke a method of the Interface, it calls your class' method.
Because both the user control and class implement the same interface, they can be seen as the same kind of object - meaning you can put them both into a collection of objects of type IYourInterface. This should give you the behavior you want.
In ASP.NET I use this technique often, by having my classes inherit from abstract class ancestors. I don't understand why WPF doesn't support this. :(
I think that you can do this but that you will have to redefine any functions and possibly some other stuff that you reference in the xaml in the child class.
IE if you have a button click event that you subscribe to in the base class xaml you will need override the button click in the child class and call the base class button click event.
Not one hundred percent sure of the the details since it's my coworkers code that I'm drawing from but thought this would give a start to anyone looking to implement this in the future.
Hi I'm trying to learn a bit of WPF and C# for a project I'm working on. I realised after working for a while that I was going to use couple of the same item and I thought it would be fitting to create my own class to make it easier to use. However now I can't reference elements defined in the XAML in the code behind like I could when just doing it in a window. The error I get is "Cannot resolve symbol 'ThaButton" in the ContactPanel.xaml.cs:
using System.Windows.Controls;
namespace WPF_OOM
{
public partial class ContactPanel : ContentControl
{
public Contact Person { get; set; }
public ContactPanel()
{
ThaButton.Content = "test";
}
}
}
My ContactPanel.xaml
<UserControl x:Class="WPF_OOM.ContactPanel:UserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<DockPanel x:Name="dp">
<TextBlock x:Name="NameTextBlock" Text="testtesttest" DockPanel.Dock="Left"></TextBlock>
<Button x:Name="ThaButton" Content="button" DockPanel.Dock="Right"></Button>
</DockPanel>
</UserControl>
Hopefully I've explained my problem well enough. I might have taken the wrong approach to this problem, let me know if there's a better way.
Cheers
Remove :UserControl from x:Class="WPF_OOM.ContactPanel:UserControl" so it looks like x:Class="WPF_OOM.ContactPanel"
Also in your code behind you have the ContactPanel inheriting form ContentControl, but in your xaml it inherits from UserControl. These base classes must match. So change them both to be UserControl or ContentControl
It looks like you created a separate .cs file? I would recommend working with the code behind generated with the xaml file. One way to get to it is in the xaml editor right-click and choose 'View code'. If you imported the xaml and .cs file then reloading the project or restarting visual studio should combine them again in solution explorer if they are not already.
I would suggest looking into the Model-View-ViewModel or MVVM pattern. It works rather nice with WPF ;)
Hope this helps get you started.
I'm sure this is easy, but new to me for WPF using C#. I know about inheriting from classes and have done so many times such as in C# WinForms projects...
public class MyClass : DerivedFromClass
{}
However, stumped in WPF and here's the issue. I want to build my own set of controls to be used as a baseline for a new learning project... preset my own styles, colors, backgrounds, and other functionality. No problem. Start first with a WPF Window and create "MyWindow".
Now, I want to take this baseline "MyWindow" and subclass THAT for yet another class of MySubClassedWindow. So, I create a new Window class, and by default, VS2010 builds the both designer and code portions of the form. I do view code on the MySubClassedWindow and find
partial class MySubclassedWindow : Window
{}
In C# using WinForms, I would just change to (and I've included the class library reference that includes the "MyWindow" declaration.
partial class MySubclassedWindow : MyWindow
{}
When I do, I get a compilation error of
Partial declarations of 'MyNameSpace.MySubclassedWindow' must not specify different base classes
Your base class should just be a class file (not a Window).
So create WindowBase.cs
public class WindowBase : Window
{
// ...
}
In MainWindow (for example) change the xaml.cs file to inherit from WindowBase instead
public partial class MainWindow : WindowBase
{
public MainWindow()
{
InitializeComponent();
}
// ...
}
In MainWindow.xaml, include the namespace for WindowBase and change Window to base:WindowBase like this
<base:WindowBase x:Class="SubclassWindow.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:base="clr-namespace:NamespaceForWindowBase"
Title="MainWindow" Height="350" Width="525">
<!--...-->
</base:WindowBase>
Having a base Window class brings a critical drawback, namely that binding to properties in your base class is much more difficult to do (and the currently accepted answer does not solve this problem). What's the point of inheriting if you cannot reference base properties? I have figured out how to set this up after some long hours, and wanted to share in the hopes that others will be spared this pain.
You may need to use things like value converters, which can only be referenced via static binding, which in my case made sense to have in the WindowBase class. I have included an example because I found it difficult to use these converters consistently in both design and run mode.
You cannot set the x:Name property of this inherited Window via XAML, but you may not need to do so if using the below approach. I have included an example of how to set the name, because inheriting from Window will not allow you to set the name at design time in the subclass. I do not recommend relying on the name of the window at design time, but setting d:DataContext should take care of any binding needs for you.
Be warned that in design mode, but not run mode, a copy of WindowBase (or the class specified in d:DataContext) will be instantiated in design mode and used as the binding context. So in very specific cases you may see data discrepancies, but in the vast majority of use cases this approach should suffice.
WindowBase.cs
````
public class WindowBase : Window
{
//User-Defined UI Configuration class containing System.Drawing.Color
//and Brush properties (platform-agnostic styling in your Project.Core.dll assembly)
public UIStyle UIStyle => Core.UIStyle.Current;
//IValueConverter that converts System.Drawing.Color properties
//into WPF-equivalent Colors and Brushes
//You can skip this if you do not need or did not implement your own ValueConverter
public static IValueConverter UniversalValueConverter { get; } = new UniversalValueConverter();
public WindowBase()
{
//Add window name to scope so that runtime properties can be referenced from XAML
//(Name setting must be done here and not in xaml because this is a base class)
//You probably won't need to, but working example is here in case you do.
var ns = new NameScope();
NameScope.SetNameScope(this, ns);
ns["window"] = this;
//Call Initialize Component via Reflection, so you do not need
//to call InitializeComponent() every time in your base class
this.GetType()
.GetMethod("InitializeComponent",
System.Reflection.BindingFlags.Public |
System.Reflection.BindingFlags.NonPublic |
System.Reflection.BindingFlags.Instance)
.Invoke(this, null);
//Set runtime DataContext - Designer mode will not run this code
this.DataContext = this;
}
//Stub method here so that the above code can find it via reflection
void InitializeComponent() { }
}
SubClassWindow.xaml
<local:WindowBase
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:YourProjectNamespace"
x:Class="YourProjectNamespace.SubClassWindow"
mc:Ignorable="d"
d:DataContext="{d:DesignInstance Type= {x:Type local:WindowBase}, IsDesignTimeCreatable=True}"
Title="SubClassWindow" Height="100" Width="300">
<!--Design-time DataContext is set in d:DataContext. That option does not affect runtime data binding
Replace local:WindowBase with local:SubClassWindow if you need to access properties in SubClassWindow-->
<Grid Background="{Binding UIStyle.BackgroundColor, Converter={x:Static local:WindowBase.UniversalValueConverter}}"></Grid>
</local:WindowBase>
Nothing is needed in the SubClassWindow code behind (not even a constructor).