I am new to WPF applications. I come from a VB6 Windows Forms background. I used to create user controls that I used in UI's to create graphic content controls like buttons with normal, down,and hover images. While I know the ultimate way to do this is create a separate project for my custom controls I am just working withing a single project to get things worked out first.
I have created a Controls folder where I have added several custom controls each inherting from a base control like Button, RadioButton, Slider, Checkbox etc. I can then add properties to each custom control for DefaultImage, DownImage, HoverImage and in the case of a Slider GripImage and GutterImage. The properties have a public set/get property so I can set the images for a specific control and then the control behavior can set the proper image.
There is an Images folder where I put all the images needed for the application.
I have created a Images.xaml ResourceDictionary that defines key names like ButtonDown to the specific image names so the image naming in the template is easier and I can swap out images easily.
A Generic.xaml gets created in the Themes folder where the basic Control Template goes. Not sure if this is best practice for storing each Control Template or not but it is what gets created by default.
My main area of difficulty is creating the template. I know what I want to do but can't get the syntax to work correctly.
In the case of the custom button I want to create triggers for IsPressed and IsMouseOver and set the controls Background ImageBrush to the proper image. When those triggers are false I want to set the background image to the DefaultImage
I'm not sure about the syntax for refering to the image property of the custom Control and how best to access it in the xamal.
I've looked at a lot of examples but none seem to do things the way I am organizing it. I don't want to hard code the images to the control. My ultimate goal is to be able to drag the custom control into a grid using the designer and set the Default, Down, and Hover image properties and then place the control how I want it in the designer. Then if I want to change the entire look of the app I can just swap out images in the Images folder and the GUI will change.
For starters, you should only use images when its actually an image. For other cases, you should draw the part using XAML primitives. In the example you mentioned, the slider thumb and gutter and tick marks, etc. should all be drawn in XAML primitives. You'll find out why down the road .
When you are inheriting from a system control, you should generally NOT write your own template from scratch, but rather dump out the Microsoft template and either inherit from it, or paste it into your assembly and modify it. Reason being is that while Microsoft pushes "lookless" controls (the XAML has no knowledge of the code and the code has no knowledge of the XAML), you'll find out they are not. Controls often rely on primitives being in certain layouts and having certain names.
Dumping out the Microsoft templates is also a GREAT way to teach you how real world controls are put together.
I typically use Expression Blend for dumping out templates.
NOTE: unless you are going to have a control that is themeless, you need to do a lot of tricks to have say an XP theme, an Aero theme, Green theme, Blue Theme,etc. so you respect the users settings. If you are just going to have one look & feel across all themes / OS'es, etc. then you don't need to worry about that as much.
Just follow the Microsoft template lead to be honest with you... they are doing it "the right way".
I should probably point out that the UI's that I build are VERY graphic in nature with borderless nonsizeable main windows with irregular shaped graphic backgrounds. All Buttons, radios, checkboxes, sliders and other basic controls are designed by a graphic designer and then sliced up for the GUI. These are NOT standard UI's. The GUI's are used for small utility setting setup (think tooltray app for setting up some small feature) or they are internal tools that are used by non computer people or used as a demo on a large screen or demo room with specific hardware to demonstrate a feature.
That said...how do I "Dump out" a control template?
Yeah, I get it. As I said in my original response, that is how you did it in Win32 / MFC / Winforms, etc. If you are going to do WPF, you should use the WPF mechanisms. Otherwise, why bother? Not trying to be a dick, just saying lol... If you are not going to do that... might as well stick with Winforms, as you won't get any of the WPF advantages.
You will be surprised what can be drawn with WPF primitives... there's a guy on here who is a REAL stud at that...
download a copy of Expression Blend (a Microsoft app) and you can drag a control on a form, right click and dump out the template. You'll get full compilable XAML, all the brushes, resources, etc.
You'll notice EVERYTHING... buttons, checkboxes, radio buttons, etc. are all drawn with XAML.
Honestly, if you are working with a photoshop graphic designer (traditional), you might as well skip WPF as you'll just be piecing together all the graphics Winform style anyways. You really need a designer that knows the WPF tools (Expression Blend, Sketch Flow, etc). Should not be too hard for a photoshop guy to learn Expression Blend (if he is interested) as it pretty much works the same way... drop primitives like lines, curves, gradients, etc. on the form and do stuff.
You ***WILL*** need to draw ***EVERYTHING*** using XAML primitives if you want to do the fancy WPF stuff... animations, fading, special fx, etc.
The tooltip pops up, but the ToolTipHeader and and ToolTipDetails are blank. The Output window says it can't find them on the view model. How do I make the binding look on the Node, not the view model?
I'm building WPF(MDI) application.
I want my main window to have some constant header and footer(like in a browser) and the area between the header and the footer will change dynamically.
I googled but didn't find any thing useful, can someone help on this one?
I got the next message at the designer: System.NullReferenceException
Object reference not set to an instance of an object.
at WPF.MDI.MdiContainer.MdiContainer_Loaded(Object sender, RoutedEventArgs e)
at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
at System.Windows.BroadcastEventHelper.BroadcastEvent(DependencyObject root, RoutedEvent routedEvent)
at System.Windows.BroadcastEventHelper.BroadcastLoadedEvent(Object root)
at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
I have a application that has a page that receives multiple packets from a TCP/IP server. Every time it receives it tries to run an event using Dispatcher.BeginInvoke which runs the event. The problem is that the event only runs on the first time Dispatcher.BeginInvoke. I believe that the reason for this is that because the thread is already running it can not be started again. Also, I have tried the Backgroundworker class and as soon as it hits my code I get an "Invalid cross thread access" error which makes me put the code back into the Silverlight Dispatcher.BeginInvoke and the origional problem occurs. How do I fix my problem?
Without seeing your code it is hard to say. I think the issue here is that you are using the Dispatcher.BeginInvoke which is actually saying, marshal any work onto the UI thread. what could be happening is that if you first action does not complete or blocks the UI then subsequent events may not bubble up to the UI thread which would not show anything.
You were right in trying another thread. Firstly do your work on another thread. At the point of updating the UI, put that bit in the Dispatcher call. So what you are saying is: Do my work on another thread. Once it is complete and I want to update my UI, marshal it onto the UI thread using the dispatcher.
Please remember that the actual code is at my office at work and I am at home. I have network security rules that don't allow me to bring code home. However, this is a Silverlight page control the Do Work Complete bw_RunWorkerCompleted is the Async event that is called once the bw_DoWork is finishes. Now, 'TimeLine timeline' is a codeplex control which is a sub-control on the main page control that displays a Silverlight timeline. How it works is that a wcf call is made which fills the timeline's List<Event> events collection that is a property of the TimeLine control. Now, when timeline.UpdateEvents is called the timeline control iterates the list and re-draws the timeline with each of the collection's event objects. The Backgroundworker class provides an Async run event and on event complete combination. I have to put the 'while (!autoEvent.WaitOne())', sorry I forgot the while in the while loop, to wait until the main thread signals so that the Dispatch.BeginInvoke(timeline.UpdateEvents) is blocked unitl the collection is updated by the wcf call or I get an exception. I know that my discription is a bit sketchy but this is all I can go on as far a specifics until in the morning. If you can help that would be great!
I have created a simple silverlight application in VS2010(Silverlight 5) for open exe file. I host the application on my iis 7 and it is working fine. when i host in online(server), the elevated permission is failed and not entered to automationfactory. kindly suggest for open exe in online.
Actually, i used image capturing in my project. I would like to open the saved picture from client machine through web browser, same time i have to save image in database. For that only i simply ask, how to open a file.
Hello Code Project,
I have a requirement in Silverlight, that If a TextBox[ContentControl] have validation error, then the appearence should be like a red wavy line, with a tool tip of error content. If it is possible , please help me with a sample silverlight application..
Correct, you have to go with silverlight only. Prism is one of the popular MVVM frame work. there no mandatory that you need to use all of these things, You can create your app with out them as well. But Building WPF/Silverlight is advisable.
Strictly speaking, PRISM is not an MVVM framework. Yes, it has some MVVM features, but it is better regarded as an application composition framework. If the OP didn't build his original app with PRISM then he's got a whole host of work in trying to convert it into PRISM.
*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington
Yes we can go with xbap application even i too thought that also.
But my basic requirement of converting this wpf to an web application is that
1) I am connecting centralized sql server with ado.net which have image data type also, so when i connect to the centralized database and fetch the data and also image am getting huge delay on getting the same.
I even asked a question on C# discussion forum on the same and they suggested me to go with image storage in physical drive and use web browser control to access the image. And instead of ado.net can use webservices.
But my thought is that if we create an web application and host the application in same server where the data base server exists will solve my problem. Thats the reason i wanted to convert into web application.
2) According to my understanding xbap application is that, when we trigger that it will download the exe to the local desktop through browser and run from local machine. If that is the case once again i hope i will be getting the same issue. If its is not the case i hope xbap would be the right option for me.
Please correct my if my understanding is wrong.
2)if i go with WCF or entity with local
servers wont it help me regarding handling data and image data types with
Sorry but I dont understand your conecrn
No, Actually my issue was to handle the image through centralized server. So i thought to host the web application and db server in the same machine. if i use ado.net it will work fine and also its working fine now. But if i go for wcf or entity model, will it also take more time to give me data having image data type?
Abhinav S wrote:
Hema Bairavan wrote:
3) And regarding XBAP, Will it
download the xbap file exe to the local machine and it will work from local
desktop like windows application like that it will connect db via internet only
Yes, an xbap file will be downloaded to you machine.
Ok thanks for your reply. So, xbap will behave like local windows application, if i use ado.net to connect centralized sql server to get data having image data type it will also take time like windows application???
i hope with this reply our conversation will come to end
By your requirement, changing the application to a webapplication (be it by web forms, silverlight or XBAP) will not solve your problem. In fact, you will only lose yet more performance.
If your application is loading images from a centralized server and that is making things slow, I think your problem is on the transfer rate of those images. If you can change your application to do a local cache of the images, you will only need to go to the server the first time (the first download) of that image, and later you can use it locally.
Surely it is good to use some mechanism to check if the image needs to be updated or not (considering the server image changes), but that's all.
Doing an web page, you will:
Have to send the application throgh tcp/ip + the images through tcp/ip. Even if the webserver does a local access, the client will use tcp/ip to get to the webserver.
The only advantage is that browsers deal with the cache for you (but considering you will need to rewrite the application, it is not a real advantage).
For the item 2. All web applications do almost the same. HTML applications can have code that executes on the server, but they will send such HTML to the client. That HTML can then asks for postbacks or call a web-service, but it executes locally (on the client).
WPF (as XBAP) and Silverlight are like the HTML code in the sense they execute on the client machine, but for anything else, they should call the webserver (a service call... WCF, for example). So, I am sure your problem is not there.