I have a custom UserControl made with C# WinForms that is exposed via COM to a C++ host app. When I wrote and debugged the UserControl, I had a C# test app and made sure the application works from that perspective. C# WinForms control in a C# WinForms environment has no problems.
When testing it through our C++ COM host application, UI events no longer work. Interacting through the hosting C++ applications UI, I can set the properties and see the response in the hosted control. However, when I click on a control the whole app freezes. I've observed the behavior with:
Buttons
Tab Pages
Check Boxes
Value Up/Down
Text Boxes
As long as I don't click on an active UI component in the hosted COM control, it behaves normally--until an event happens where the COM control needs to create a new tab page.
I've tried setting all kinds of break points, but it freezes before we get to the hosted COM control and the whole app is frozen. The alternate COM control that is arguably more complicated doesn't seem to have this behavior.
Any clues what is going on? I'm lost trying to figure out the problem.
New Information
The contents of the whole UserControl was in a TabControl with several tabs. I created a single button outside the TabControl, and when that was clicked I could interact with the controls inside the TabControl on each of the pages that were defined when the ComControl was initialized.
However, If I create a new TabPage or instantiate a FolderBrowserDialog I'm right back to the old behavior. So, how do I use TabPages and such safely from within a ComControl?
Related
I have gone through couple of articles on hosting active X control.
http://msdn.microsoft.com/en-us/library/ms742735(v=vs.100).aspx
I see the example uses a Windows Media Player, which is shown to the user.
My requirement is: I have an active X control, and there is no UI associated with it. There is some business logic associated with it and my application is WPF.
My doubt is whether I should still go for the way of using WindowsFormsIntegration for hosting the activeX control or should I simply instantiate the active X control in the helper class and use it through out the life time of my application?
Well hosting an ActiveX component doesn't necessarily mean displaying an ActiveX component. It is perfectly valid to have hidden elements, even if they are fundamentally visual elements, just to have access to their particular properties (and logic). Indeed many customized WPF controls are put together using a variety of visual controls which the user never actually has a clue about. I say host it discreetly in the background and use it was you will.
I'm writing a program to implement COM component in C#. This component provides a UI component too. In the interest of making it easy to implement future additions to the component, I decided to write the UI in Xaml using WPF and wrapping it in an ElementHost control to provide the handle back to to the COM consumer.
Here's where this gets interesting. The element is being hosted in a win32 tab control. The first time the tab is selected, it loads fine. Switching to another tab and coming back causes it to not draw the component correctly. If I move the mouse through it, it'll draw the TextBox elements, but it'll never redraw the whole UserComponent.
I've tried every possible solution I've seen suggested, from changing the height/width values of the component to putting the HwndTarget in SoftwareOnly rendering mode.
I'm not sure what to try at this point, so suggestions are welcome. I'd really like to do this without using Windows Forms as the future maintainers of this aren't the best programmers and it's a lot easier to tell them to write up a Xaml file with data bindings than manually lay out a form and set the values in the code-behind.
Haven't met such problem yet.
Try to force refresh or focus (methods) to the hosting wrapper or HwndSource when switching to the hosting tab.
I have an interesting case to solve:
I have a native (winapi) application, which uses MDI. This application allows me to extend itself with a simple scripting language. The scripts are launched on different thread than UI thread (although I can get the UI thread ID with appropriate functions). The scripting language also allow me to launch any c++ code (through LoadLibrary).
What I would like to achieve is to create a new window inside this application, which could host WPF and "attach it" as a MDI child window to MDI client (mdi area). Also, I would like this window to properly "talk" to MDI area, for example update list of windows in mdi menu.
So far, my first guess was to just create a WinForms window, host WPF inside, and then try to make it mdi child window by setting MDI client as it's parent (because my hosting application is not written in c#, I only have a handle, so I did this with User32.SetParent() P/Invoke). This worked almost well, after I attached my script thread to GUI thread, but I had few problems with it: the MDI menu with active windows did not update, the window did not interact correctly (it stayed on stop when it shouldn't etc.).
Then, I tried to set flags (style, exStyles) with SetWindowLongPtr. It changed my window's behavior a bit, but that was still not it.
Now I'm considering using CreateMDIWindow function, or doing it by SendMessage, according to docs sending message should create a window, even if I send it from different thread. The problem is, that this way would give me a native handle only, and I could not find (yet) any way of hosting WinForms / WPF inside it.
I'm curious if anyone tried to do something similar and had any results with it? Which way would be the best - trying to create a WinForms window and add it to MDI client, or create a native window and try to host WinForms in it (any particular way of doing that)?
Most answers for this question I have found are dealing with situation where hosting application is managed, so you can just set .MDIParent property, which won't work in this case I'm afraid.
I have a Silverlight control containing an image. I want the user to be able to drag the image out of the Silverlight application and drop it anywhere they would be able to drop an image. For example, to the Desktop or to a PowerPoint slide or Word document. Everything that I have read thus far says it cannot be done but I find that hard to believe. I'm very new to Silverlight and RIA development so any help would be much appreciated.
Below is the code sample in my WinForm Form but the drag never starts.
string[] aString = { imagePath };
DataObject data = new DataObject(DataFormats.FileDrop, aString);
data.SetData(DataFormats.StringFormat, imagePath);
DoDragDrop(data, DragDropEffects.Copy);
Well the trouble is that a drag operation in Silverlight doesn't have simple access to anything outside the browser (by design). Depending on the user's settings you even have to get explicit permission for clipboard operations and sandboxed temporary file storage. This really sounds like a task better suited to a WPF application (perhaps with web deployment?) or some other desktop application technology.
However, that being said here are some things you could try/consider:
Silverlight/Javascript/ActiveX combination hosted in Internet Explorer
Silverlight 5 "Out of Brower" & P/Invoke (I heard P/Invoke will be supported when Silverlight 5 comes out)
Silverlight connecting to a web service running on the same computer (crazy, but you didn't ask for "not crazy", you asked for possible)
I am not very familiar with drag and drop in the Win32 API so it would take a lot of research and experimentation before I could confirm that this was even possible (and I can already tell you it isn't practical).
Edit: Based on the extra information you provided about the question I suspect it is possible to do what you are attempting. First, are you using WPF or WinForms? I assume WPF but one of your comments says WinForms. I wasn't very familiar with WPF drag/drop operations, but having looked into it, I think your code is on the right path. I created a WPF application and initiated a drag during a KeyDown event. This meant that the mouse button was not necessarily pressed. If I initiated the DragDrop while the button was down it worked. If I initiated while the mouse button wasn't down, I had to push the mouse button down and the drag operation would start (this was unexpected since I assumed the mouse would have to already be down). If I pressed the mouse down outside the application, then gave the WPF app focus (ALT+Tab), then initiated the DragDrop while the mouse button was still down, it didn't work. I got a reference to the MouseDevice and checked the LeftButton property, and the state was showing as "Released" even though the button was still being held down. It seems the key here is the way drag/drop interacts with internal mouse state. You might have to find a way to set the mouse state (maybe with the UI Automation API?). At this point it should be painfully obvious that this whole thing is a hack (even though it is probably possible to get it to work somehow).
The solution we came up with was as follows. The RIA i.e. Silverlight sends a message to our Desktop application WinForms with the path of the image to drag along with the bounding rectangle in screen coordinates that we want to start the drag from. The Desktop code creates and places a Panel over the area that we want to drag from. This panel is where we use DoDragDrop to initiate the native drag when the user left clicks. Since this panel is placed outside and above the silverlight control, everything works perfect. Sandbox defeated.
I have been working on some Silverlight apps for the past few months and fully investigated your exact requirements only to find it was not possible. I believe you can drag from the file system, from Silverlight control to control, but not to the file system.
Does Silverlight 4 support drag and drop from app to desktop?
http://msdn.microsoft.com/en-us/library/dd772166%28v=vs.95%29.aspx
I am currently exploring the option of porting some older VB6 application to WPF with C#. The plan, in phase one, is to port several key forms and not all the application. The theoretical goal is to open the VB6 form in a container of some sort within WPF via an ActiveX dll.
Is this even possible?
I've tried looking at the Interop and can't seem to find a solid example of how get it to work with anything but Win32 controls, not a full form. I have full access to the old VB6 code and can modify it in anyway needed.
The following screenshot of the main WPF app would serve as the wrapper/container:
http://www.evocommand.com/junk_delete_me/main_menu_mockup.png
The current VB6 maintenance screen that would be loaded in the “white space” section on the right side of the previous screen.
I was able to accomplish the task with the following steps:
Created a new VB6 Active X Control Project. Copied and pasted the entire contents of the VB6 form controls and code behind into the new control. There are several elements that have to be handled in switching to a control:
you lose the ability to display
the caption of the form in the
previous manner. You can work around
it with alternate controls
(label/borderlesstextbox, etc) that
accomplish the same functionality if
needed. This wasn’t a priority since
each screen was being hosted in a
browser like tab system in our new
.Net project.
All mousepointer references have to
be changed from Me.Mousepointer to
Screen.mousepointer
You cannot use Me.Hide and have to
alternate events to hide the .Net
container.
Any and all references to
Me.[anything] have to be removed or
replaced with UserControl.[anything]
if they are applicable.
If you use any functions that
reference a
[yourcontrol].Contianer.Property on a
form they will need to be altered to
loop through the UserControl.Controls
collection instead and “Container” is
invalid for vb6 ActiveX controls
All non-modal forms/dialog boxes
must be removed from the project as
there is now no Hwnd to handle in WPF.
You get an error of 'Non-modal forms
cannot be displayed in this host
application from an ActiveX DLL,
ActiveX Control, or Property page'.
In our case we had a simple splash
screen that would display when certain
long processes/reports displayed to
let the user know what was running.
I was unable to directly add the VB6 control via the interop to a WPF project . As such a new .Net “Windows Form Control Library” project was created. A reference to the VB6 OCX was added to the project. The VB6 Control s were then added to the .Net toolbox by “right click” –> “Add Item” and pointing a com reference to the VB6 control ocx. The .Net control was then used to host/serve the VB6 Control.
To display host a form in the VB6 and get it to fire the necessary initialization functionality the VB6 OCX controls were defaulted in a Visible.False manner so they were initially added to the .Net OCX as invisible controls. When needed the VB6 control is set to visible = True which fires the UserControl_Show() event. All code formerly in Form_Load() was moved to this event. The show event was the easiest method of accessing the Form_Load as needed. MSDN: “The control does not receive Show events if the form is hidden and then shown again, or if the form is minimized and then restored. The control’s window remains on the form during these operations, and its Visible property doesn’t change.”
Wrapping the vb6 controls within a .Net Winform control resolved the issue with Radio/Option buttons being rendered as black as outlined elsewhere in one of my responses to this question without having to convert the frames to Picture boxes as suggested.
In the WPF app as a menu choice is selected xaml code is dynamically created and displayed via a wrapper with a WindowsFormsHost tag. A dynamically created control object from the .Net winform app is then pushed into the WindowsFormsHost tag on the xaml and the control is made visible on the .net project which fires vb6 UserControl_Show and then load and display of the vb6 form.
I think what you will have to do is extract the VB6 form contents into an ActiveX control. You can then expose this in your ActiveX dll and place that in your WPF form. I doubt it's possible to host a VB6 form within any other type of form.
Can you even load that VB6 form in another VB6 form? I suggest you get that working first.
There is no reliable way to set parent of a VB6 form. You can always hack it or use plain ActiveX control (UserControl in VB6) as UI container instead of VB6 forms.
I found a method to do what was needed within WinForms rather than WPF at this point.
http://www.codeproject.com/KB/vb-interop/VB6formsinNET.aspx
I figure if I can get it working 100% there I can port it over to WPF or worse case host the WinForm element in the WPF form if I absolutely have too (U-G-L-Y).
Anyway, I've gotten a bit closer, but am having a very odd issue with certain controls painting too the screen. Radio/Option buttons are rendering as solid black:
http://www.evocommand.com/junk_delete_me/optionbuttons.png
I've tried explicitly changing the controls' background color from buttonface to a fixed color and it still does it. I'm assuming it's a layering issue with the option buttons being within the frame control. I'm at a bit of a loss on how to proceed without massive rework of the VB6 content to change the options buttons to checkboxes. It's a hefty app and there are 600+ option button controls across the application that I don't exactly want to deal with.
EDIT:
I was able to confirm it has something to do with the layering of the option within a Frame control. If pulled out to the base form the issue does not occur:
http://www.evocommand.com/junk_delete_me/optionbuttons2.png