CODEWITHSUNDEEP
c#wpf
Felix
Felix

Reputation: 3476

WPF TextBox doesn't take input, space and backspace works

I have textbox inside a usercontrol and I add the usercontrol to the MainWindow with the following XAML:

 <Views:MyUserControl />

I have one TextBox in MyUserControl, the problem is that the TextBox doesn't take any input. Backspace och space works, but if I press the letter och numbers no text is added to the TextBox.

I have made sure that the text is not just hidden in the TextBox. I have also tried to add a RichTextBox to MyUserControl with the same result, it doens't take any input (beside space och backspace).

I have also tried to add a TextBox to the MainWindow with the same result; it doens't take any input (beside space och backspace).

Also MyUserControl is added in a TabControl and TabItem.

Any clues?

Edit: Additional information Forgot to write that I'm opening/creating the WPF Window from a WinForm application. When I set my startup project in VS10 to be my WPF-project it work great with the keyboard input to the TextBox.

How come?

Im opening/creating my WPF windows with the following code:

MyWpfProject.MainWindow mw = new MyWpfProject.MainWindow();
mw.Show();

Edit: Solution So I guess my real problem was that is was opening the WPf project from a WinForms application.

I added the following code:

MyWpfProject.MainWindow mw = new MyWpfProject.MainWindow();
ElementHost.EnableModelessKeyboardInterop(mw);
mw.Show();

"The EnableModelessKeyboardInterop() call is necessary to handle keyboard input in the WPF window if loaded from a non-WPF host like WinForms." http://weblogs.asp.net/jdanforth/archive/2008/07/29/open-a-wpf-window-from-winforms.aspx

Upvotes: 24

Views: 10156

Answers (4)

Dylan Rice
Dylan Rice

Reputation: 1

I would like to add my own answer just on the off chance it can help anyone else with the same or similar problems. My particular use case was a .Net windows form created by an addin. The addin was running out of Autodesk Inventor which I think may be WPF (but don't take my word for it.) The addin had several windows forms some docked within the application and with some acting as popups or a separate secondary window. The solution was to set the windows forms owner to one of the docked forms. Doing this allowed text to be edited and entered into its textboxes. Very niche solution to a niche problem but hopefully it may help someone at some point in the future. 

private void CreatePanels(DockableWindows DockableWindows)
{
    //Create the dockable window that the panel form will live on. 

    DockableWindow SideWindow = 

        DockableWindows.Add(SidePanelNames.GUID, SidePanelNames.InternalWindowName, SidePanelNames.Title);

    //Configure the windows settings. 

    SideWindow.ShowTitleBar = true;

    SideWindow.ShowVisibilityCheckBox = true;

    SideWindow.DisableCloseButton = false; 

    SideWindow.Visible = true;

    SideWindow.AddChild(SidePanel.Handle); //Add the forms as children and then display to the user. 

    SidePanel.Show(); //Display the panel to the user. 
}

/// <summary>
/// Creates the Display window were order and patient information is displayed to the user. 
/// This method makes the adjust device form the owner of the display window. Because of this
/// dependecency it should be run after the panels have been created. 
/// </summary>
private void CreateDisplayWindow()
{
    DisplayForm = new DisplayForm //Create the display form. 
    {
        Owner = SidePanel //Doing this allows text boxes to have values entered into them. 
    };

    DisplayForm.Show(); //Show the display form to the user. 
}

//Adding the side side panel as the owner of the display form was effectively the only change I needed to make.

I will add a few words of warning for anyone attempting this solution. Simply put I've since found out it's not great. It prevents the form or any of its controls from detecting certain key presses (enter and tab) which matters a lot for my usage. You'll find a much better and solution here https://forums.autodesk.com/t5/inventor-forum/dockable-window-with-wpf-controls-don-t-receive-keyboard-input/td-p/9115997

Upvotes: 0

Matthis Kohli
Matthis Kohli

Reputation: 1993

I had the same problem but my Environment was built such that I could not apply the solution above. As it turned out that wasn't the problem. It was much more easier than expected.

I host a WPF User Control inside WinForms. My WinForms MainView (Startup form) did override the "ProcessCmdKey". Because of logical errors it returned nothing.

Nevertheless I received all key events in code behind in my XAML file but this events never updated the "Text" of my text box. Only space and backwards did so and this were the key events I didn't receive in code behind.

So in case you don't think of the simplest solution here it is for VB.NET.

STRG+F "ProcessCmdKey" and make sure that you Return the correct value of you may completely uncomment it just to verify that it isn't causing you the same trouble as it did to me.

Upvotes: 1

Felix
Felix

Reputation: 3476

Answer to my own question (if someone else run into the same problem): If you open a WPF-form from a WinForms application you have to do the following to get keyboard input:

MyWpfProject.MainWindow mw = new MyWpfProject.MainWindow();
ElementHost.EnableModelessKeyboardInterop(mw);
mw.Show();

"The EnableModelessKeyboardInterop() call is necessary to handle keyboard input in the WPF window if loaded from a non-WPF host like WinForms." http://weblogs.asp.net/jdanforth/archive/2008/07/29/open-a-wpf-window-from-winforms.aspx

Upvotes: 54

kite
kite

Reputation: 679

maybe your user control is getting the keyboard event instead of your textbox? try to search in this way, it happens with mouse buttons.

Upvotes: 2

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