in winForms, I have .Handle property, how do I get the equivalent to in WPF?
I tried using WindowInteropHelper but it does not suporte RichTextBox,only Window types.
Thanks in advance.
Controls in WPF do not have associated WinAPI handle, like WinForms control do. WPF uses only one WinAPI window to process window messages from OS and encapsulates it in Window class instance. The best you can do is to navigate through parents of your control until you find a Window and get the handle. As far as I understand this will likely be the same handle as one returned by WindowInteropHeler.
UPD.
To make this answer more useful and out-of-box'y here is some code (not tested though):
IntPtr hwnd = new WindowInteropHelper(Window.GetWindow(userControlRefernce)).Handle;
RichTextBox does not have HWND handle in WPF. You can still use a RichTextBox from WinForms library using WindowsFormsIntegration assembly, if you really need this handle.
Remember that you can always check what elements have or do not have handles using Spy++ utility.
Related
Does anybody have any simple examples on how to provide C++ code a window that can be used for DirectShow rendering from a C# UserControl?
I am currently able to create a separate and render to a window via a WS_POPUP window and match its size/position to the existing control window I have reserved for the video pane on the WPF control.
As soon as I try to make the window a child of the WPF control or set WS_CHILD on a new or existing window everything stops rendering and I receive no error explaining what is going on.
Ideally I would be able to pass existing HWND from C# through to the C++/DirectShow class and use it there as-is.
P.S.
Before you ask "Why don't you just... do something different", I need to control DirectShow from C++ and have to display the results via a C# (WPF) control. I have no control over these conditions.
C#/WPF (control reserved) <---> C++/CLI <---> C++/HWND/DirectShow
The best way of achieving this would be to use VMR in the windowless mode. The following snippet of code illustrates this(This is for working code. I have removed error checks etc but should give you an idea):
pVMRConfig->SetRenderingMode(VMRMode_Windowless);
m_VMR->QueryInterface(IID_IVMRWindowlessControl9, (void**)&pVMRWindowlessControl);
//displayWnd is what you pass in from your C# app
pVMRWindowlessControl->SetVideoClippingWindow(displayWnd);
RECT rcDest;
GetClientRect(displayWnd, &rcDest);
hr = pVMRWindowlessControl->SetVideoPosition(NULL, &rcDest);
In a WPF app of mine, I have to let the user choose a certificate. I do this via the X509Certificate2UI.SelectFromCollection-method. For proper dialog handling, the SelectFromCollection-method needs an IntPtr of the parents Hwnd. I have found the following code to provide this:
HwndSource source = (HwndSource)HwndSource.FromVisual(Window.GetWindow(this));
var certificates= X509Certificate2UI.SelectFromCollection(...,source.Handle);
So far, this works fine. My question is, because I have no big knowledge of Win32 or interop, if I have to do some cleanup code after this, or if there are some pitfalls in using the HwndSource-class like I did above?
I have seen that HwndSource implements IDisposable, but disposing the object after use closes the parent window. Therefore this seems not to be the intended usage.
WPF window is made up of two parts:
Window area which is made up of Operating System Window
Non - Window area which is inside a WPF window
Now, a WPF window being a ContentControl holds everything as its Content. So you can say every pixel of the Content inside the Window class is held by the Outside window. Every Visual of WPF does not have its own HANDLE associated with it, rather it is a content for the outside window element.
For detail refer to this - http://www.abhisheksur.com/2010/12/win32-handle-hwnd-wpf-objects-note.html
So, when you are disposing that handle, you are actually disposing your main window handler which results in close of complete application.
Hence, you are here only fetching your window handler and not creating anything which you might need to dispose..!!
I am integrating a webcam in a WPF application. I can see the camera feed in the main window, as I pass its HANDLE on to the DirectShow functions. But this is not what I want.
The main form has a Image control, where I'd like to see the output. However, in order to do this, I need the control's Handle.
Any hint on how to do this?
Thanks in advance,
Gianluca.
An Image Control in WPF, unlike Windows Forms, doesn't actually have an HWND.
WPF works differently than Windows Forms - each control is not a wrapper around a native "window" with a handle, but rather composed together using Direct3D at runtime by the layout system.
If you need to actually host output from a Webcam inside of a WPF window, you should look at using HwndHost (or a subclass). The simplest way is often to just host a Windows Forms control inside of a WindowsFormsHost, though managing an HWND yourself via HwndHost is more efficient.
Using an WindowsFormsHost and a picture box inside is a good solution that I used for a similar problem where I needed a handle to display a video stream. But be careful, in order to work, the Window that is hosting the WindowsFormsHost control must have AllowsTransparency="false"!
I feel like I'm missing something really obvious here.
I know that forms in general have a Handle property, but I am using a System.Windows.Controls.TextBox and it does not have a Handle property.
How do I access the TextBox's handle? I noticed that RichTextBox has the Handle property, so why not the regular TextBox?
You can just call Handle on the TextBox. It is an inherited property from System.Windows.Forms.Control.
Edit: Question was updated to ask about WPF
WPF doesn't use handles like a typical Win32 application or WinForms application. Each control is not its own Window in WPF. You can verify this with Spy++, it cannot differentiate between each control. Therefore you cannot SendMessage to the individual controls like you can with WinForms and Win32 apps.
You can use WindowInteropHelper to get the parent window handle of a WPF window.
In the past I've used the (P/Invoke) method GetWindowText to grab the window title text of a running application, regardless of it being Win32, .NET or otherwise.
What I'm trying to figure out is if there is a way to access text on actual controls, inside a form. I realize that this would probably be difficult and I will likely be address the controls by some random hex value or something and that it could break if the software every changes at all (it's something I have no control over). But, I'm just trying to do this to add some data polling to my media center setup and would like to be able to pull some information from a media player for which there is no API.
So, is there any sort of API (I'd imagine I would have to P/Invoke into it) that allows you to do this? Code examples would be greatly appreciated.
I believe GetWindowText takes the window handle as parameter, many controls ( but not all of them ) also have the window handle and you should be able to use the same API to get the text out of them.
How to get the handles of child controls is then another story but Win32 has all you need for it.
Send the WM_GETTEXT message to the control once you know its handle.
To work out its handle first of all use Spy++ or some such tool to find the name of the top level window and its window class name. Send this to FindWindow to get the top level window handle. Finally call EnumChildWindows to walk the children. Spy++ can also tell you how to identify which child is of interest.
Of course you may be unlucky and find that the control of interest is implemented without its own window handle, but Spy++ will tell you that too.