How to test the accessibility object of a windows form application? - winforms

In WindowsForms each control having the AccessibilityObject. If its a custom control derived from a Control then its also having the AccessibilityObject.
How can i test the accessibility object of the custom control in windows forms.
Is there any testing tools is available to test the accessibility object?
protected override AccessibleObject CreateAccessibilityInstance()
{
if (accessibilityEnabled)
{
return new CustomControlAccessiblity(this);
}
return base.CreateAccessibilityInstance();
}
What is the usage of the custom accessibility object and how it can be used in the accessibility aids?

Related

Enable groups in the ListView hosted by WPF

There is an old Winforms control which I hosted in WPF app.
Control makes use of System.Windows.Forms.ListView inside and this ListView uses Groups feature.
The problem is that this control when hosted by WPF does not show groups.
I've manually compared properties of ListView when it's hosted by Winforms app and WPF app.
For both ListViews ShowGroups property is true.
However there is a property called GroupsEnabled and it's true when control is hosted in Winforms and false when it's hosted in WPF.
I've found definition here:
internal bool GroupsEnabled
{
get {
return this.ShowGroups && groups != null && groups.Count > 0 && ComctlSupportsVisualStyles && !VirtualMode;
}
}
VirtualMode is false for both but ComctlSupportsVisualStyles is true for Winforms hosting and false for WPF app.
Code of ComctlSupportsVisualStyles from the same source:
private bool ComctlSupportsVisualStyles {
get {
if(!listViewState[LISTVIEWSTATE_comctlSupportsVisualStylesTested])
{
listViewState[LISTVIEWSTATE_comctlSupportsVisualStylesTested] = true;
listViewState[LISTVIEWSTATE_comctlSupportsVisualStyles] = Application.ComCtlSupportsVisualStyles;
}
return listViewState[LISTVIEWSTATE_comctlSupportsVisualStyles];
}
}
I think I need to set Application.ComCtlSupportsVisualStyles somehow in my WPF code.
And this must be System.Windows.Forms.Application and not System.Windows.Application.
Is there any way to do it?
Enabling visual styles for your application should fix the problem:
System.Windows.Forms.Application.EnableVisualStyles();
The WinForms ListView control does not support groups unless visual styles are enabled (technically, unless version 6 of the ComCtrl32 library is used, which is the same version as required to support visual styles).
See also: How to: Enable Visual Styles in a Hybrid Application

How can a Category attribute be specified in a UWP custom control?

In WPF, when creating a custom control, you could cause your custom properties to be categorized in the Visual Studio/Blend Properties window by adding the following attribute:
[Category("MyCustomProperties")] <---------
public bool MyProp
{
get { return (bool)GetValue(MyPropProperty); }
set { SetValue(MyPropProperty, value); }
}
There is no CategoryAttribute in WinRT's System.ComponentModel namespace.
How is the same thing accomplished on the Universal Windows Platform?

Windows Narrator reads the names of all the controls in the window (even hidden ones)

I need to make my application visually impaired friendly... and I am facing this problem: Windows Narrator reads all the controls names in the window despite that some of them are hidden.
I have another app that I used WinForms to write it, and there it works fine.
After looking in the UI Spy I saw that WinForms app is not exposing hidden controls and WPF is exposing all the controls in the window.
Can it be that it's a bug in WPF?
I was having the same problem.
Based on Alexis's answer, I wrote the code bellow. It works for me.
public class MyAutoComplete : RadAutoCompleteBox
{
public MyAutoComplete ()
{
//init stuff here
}
protected override AutomationPeer OnCreateAutomationPeer()
{
return new MyAutomationPeer(this);
}
}
internal class MyAutomationPeer : RadAutoCompleteBoxAutomationPeer
{
public MyAutomationPeer(FrameworkElement owner)
: base(owner)
{
}
protected override List<AutomationPeer> GetChildrenCore()
{
return new List<AutomationPeer>();
}
}
If your controls are already in the visual tree, this behavior is the normal one, because UI Automation tree based on the Visual tree. So if you want to prevent of reading unnecessary elements using screen readers, you have to load them on demand.
You can also override the OnCreateAutomationPeer method in controls that contain visible and hidden elements to return your own AutomationPeer. Then you can override the GetChildrenCore method and return modified children collection. To update automation children tree, you need to call the AutomationPeer.ResetChildrenCache() method and the AutomationPeer.RaiseAutomationEvent(AutomationEvents.StructureChanged) one.

How to use Caliburn Micro in a WinForms app with one WPF form

We have a (massive) legacy WinForms app which, through a menu item, opens up a WPF form. This WPF form will host an Infragistics grid, and some buttons/drop-downs.
This lone WPF form represents the nascent stage of a migration to WPF. Later on, more components of the app will move to WPF, and ultimately the entire app itself.
As part of the migration, we would like to use Caliburn Micro. Hence, it would be nice if we could start by using it with this lone WPF form.
Can someone please provide some pointers on how to use Caliburn Micro with the WPF form?
Or perhaps tell me why it may not make sense to use Caliburn Micro just yet?
The documentation I've read so far involves boot strappers that ensure the application starts with the desired root view model, rather than the scenario above.
Many thanks!
After much Googling and going through the Caliburn Micro source code, I've come up with an approach that works in a sample test application. I can't post the test application here for certain reasons, but here's the approach in a nutshell.
Create a WinForm with a button.
On button click, show a ChildWinForm
In the load handler of the ChildWinForm:
// You'll need to reference WindowsFormsIntegration for the ElementHost class
// ElementHost acts as the "intermediary" between WinForms and WPF once its Child
// property is set to the WPF control. This is done in the Bootstrapper below.
var elementHost = new ElementHost{Dock = DockStyle.Fill};
Controls.Add(elementHost);
new WpfControlViewBootstrapper(elementHost);
The bootstrapper above is something you'll have to write.
For more information about all it needs to do, see Customizing the Bootstrapper from the Caliburn Micro documentation.
For the purposes of this post, make it derive from the Caliburn Bootstrapper class.
It should do the following in its constructor:
// Since this is a WinForms app with some WPF controls, there is no Application.
// Supplying false in the base prevents Caliburn Micro from looking
// for the Application and hooking up to Application.Startup
protected WinFormsBootstrapper(ElementHost elementHost) : base(false)
{
// container is your preferred DI container
var rootViewModel = container.Resolve();
// ViewLocator is a Caliburn class for mapping views to view models
var rootView = ViewLocator.LocateForModel(rootViewModel, null, null);
// Set elementHost child as mentioned earlier
elementHost.Child = rootView;
}
Last thing to note is that you'll have to set the cal:Bind.Model dependency property in the XAML of WpfControlView.
cal:Bind.Model="WpfControls.ViewModels.WpfControl1ViewModel"
The value of the dependency property is used passed as a string to Bootstrapper.GetInstance(Type serviceType, string key), which must then use it to resolve the WpfControlViewModel.
Since the container I use (Autofac), doesn't support string-only resolution, I chose to set the property to the fully qualified name of the view model. This name can then be converted to the type, and used to resolve from the container.
Following up on the accepted answer (good one!), I'd like to show you how to implement the WinForms Bootstrapper in a ViewModel First approach, in a way that:
You won't have to create a WPF Window and,
You won't have to bind directly to a ViewModel from within a View.
For this we need to create our own version of WindowManager, make sure we do not call the Show method on the Window (if applicable to your case), and allow for the binding to occur.
Here is the full code:
public class WinformsCaliburnBootstrapper<TViewModel> : BootstrapperBase where TViewModel : class
{
private UserControl rootView;
public WinformsCaliburnBootstrapper(ElementHost host)
: base(false)
{
this.rootView = new UserControl();
rootView.Loaded += rootView_Loaded;
host.Child = this.rootView;
Start();
}
void rootView_Loaded(object sender, RoutedEventArgs e)
{
DisplayRootViewFor<TViewModel>();
}
protected override object GetInstance(Type service, string key)
{
if (service == typeof(IWindowManager))
{
service = typeof(UserControlWindowManager<TViewModel>);
return new UserControlWindowManager<TViewModel>(rootView);
}
return Activator.CreateInstance(service);
}
private class UserControlWindowManager<TViewModel> : WindowManager where TViewModel : class
{
UserControl rootView;
public UserControlWindowManager(UserControl rootView)
{
this.rootView = rootView;
}
protected override Window CreateWindow(object rootModel, bool isDialog, object context, IDictionary<string, object> settings)
{
if (isDialog) //allow normal behavior for dialog windows.
return base.CreateWindow(rootModel, isDialog, context, settings);
rootView.Content = ViewLocator.LocateForModel(rootModel, null, context);
rootView.SetValue(View.IsGeneratedProperty, true);
ViewModelBinder.Bind(rootModel, rootView, context);
return null;
}
public override void ShowWindow(object rootModel, object context = null, IDictionary<string, object> settings = null)
{
CreateWindow(rootModel, false, context, settings); //.Show(); omitted on purpose
}
}
}
I hope this helps someone with the same needs. It sure saved me.
Here are somethings you can start with
Create ViewModels and inherit them from PropertyChangedBase class provided by CM framework.
If required use the EventAggregator impelmentation for loosly coupled communication \ integration
Implement AppBootStrapper without the generic implementation which defines the root view model.
Now you can use the view first approach and bind the view to model using the Bind.Model attached property on view. I have created a sample application to describe the approach here.

WPF & WinForms Integration and Application Class

I am planning to create a WPF application with a main window which would launch various WinForms. Some of the WinForms use the System.Windows.Forms.Application class (DoEvents, Application.Path, etc). Do you think that there will be a problem in doing this?
Can I still use System.Windows.Forms.Application.DoEvents() from a WinForm that is launched from a WPF application?
The main problem will the ability to instantiate the Windows Forms window and set it's owner to that of the WPF window. The Winforms will want a IWin32Window which a WPF window isn't. To get around this, you need to make a custom class.
I found this code on Mark Rendle's blog (I've copied it here as I had to use the Google Cache to access the page).
LINK - WARNING: May not work
class Shim : IWin32Window
{
public Shim(System.Windows.Window owner)
{
// Create a WindowInteropHelper for the WPF Window
interopHelper = new WindowInteropHelper(owner);
}
private WindowInteropHelper interopHelper;
#region IWin32Window Members
public IntPtr Handle
{
get
{
// Return the surrogate handle
return interopHelper.Handle;
}
}
#endregion
}
and it's method of use:
namespace System.Windows.Forms
{
public static class WPFInteropExtensions
{
public static DialogResult ShowDialog(
this System.Windows.Forms.Form form,
System.Windows.Window owner)
{
Shim shim = new Shim(owner);
return form.ShowDialog(shim);
}
}
}
I haven't tested this code, but reading around the internet, it appears that you can host Winforms windows inside of a WPF app.
I just found this link on MSDN that has a very detailed description of how to interop a Win32 control/window in a WPF application.
Hope these help you out.
I've been doing this sometimes and didn't encounter any problem.
However i don't really recommend it, you should prefer WPF when you are in a WPF Application.
for exemple if you want application path use this :
System.Reflection.Assembly.GetExecutingAssembly().Location

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