I am not using anything other than a simple WPF application project in visual studio. I've implemented an mvvm application.
I want to display a list of content changes made by a user. I have a main window view model and it currently just builds a strings with changes. I have objects that I can reuse to display their properties (the content).
Currently, I use a MessageBoxResult to show a really long string with the changes. This is a terrible design (I know), but I couldn't really find an answer to what class a regular wpf project has that would allow me to achieve what I want.
I know there is a popup class I can use. In practice, which is better-- another view model for the dialog, or a popup?
Can anyone provide a simple example of one of the two approaches?
Thank you in advance for your response.
What I've done in the past is have a simple Border control, and inside of a TextBlock and whatever Button controls I need. I bind the TextBlock.Text to a public string property named "MessageBoxMessage" which calls OnPropertyChanged(). I bind the Command of each Button to a separate public ICommand which specifies what action to take in the view model when the button is clicked. I then bind the visibility of the Border control - which contains all of the other controls I mentioned - to a Visibility property.
When I want to show a dialog, I set the MessageBoxMessage to the message I want to show, makes sure the commands are set properly, and then set the Visibility on the Border to Visibility.Visible. This shows the box (border), message, and buttons.
You can even implement a semi-transparent rectangle underneath the border (over the rest of the form) that you set to visible at the same time. This will give you the nice "form dimmed" effect and also block the normal form controls from being clicked. A general note - for this to work, these controls need to be at the very bottom of your XAML as the z-index among controls at the same level is inferred from their placement in the XAML - lower in the code is top level on the form.
Let me know if you have any questions about implementing this if it sounds like what you are looking for.
I've been reading some explanations about the difference between User and Custom Controls, for example this:
http://www.wpftutorial.net/CustomVsUserControl.html
I want to create, for example, a simple composition of a datagrid with 2 comboboxes which are responsible to change the values from the datagrid's items. I want to create a specific control for this because I'm going to use it a lot of times. I would like to implement the logic behind and then in the xaml invocation I only have to specify the itemsSource.
For this example should I create a User or Custom control? Since I will have properties and logic, should I have a viewmodel for this control?
EDIT: Do you know some articles with clear conceptual separation between these 2 options?
Choice is not only between user control and custom control, but among user control, custom control, customizing control template, customizing data template, header template (for collection based controls), attached properties.
Refer to Control Authoring overview
I go by following order of consideration
Attached Properties : If functionality can be achieved, I use attached properties. Example, Numeric text box.
Control Template : When requirement can be fulfilled by customizing the control template, I use this. Example, circular progress bar.
Custom control: If control template cannot do it, I use custom control. Provided I need to customize/extend already present control. Example providing Sorting, Filtering based on header row in GridView (GridView is present in metro apps, used just to illustrate the example)
User control: Least preferred one. Only when composition is required, and I am unable to do it using custom control. Like in your example, 2 Combobox, and 1 datagrid. User controls does not provide seamless lookless feature that can be leveraged through custom control or control template.
You already have some great answers that explain the differences but also understand that custom controls and UserControls have different purposes:
A UserControl typically encapusulates some sort of composite behaviour. If you have an application that needs to edit contact details in many places, for example, you could create a custom control that has the labels and text fields for all the data laid out with a submit button that has the relevant code and reuse this control throughout your application.
A custom control is a control that is derived from one of the WPF control classes (E.G. Control, ContentControl etc.) and has to be created in code.
These control usually have a single cohesive purpose (think TextBox, ComboBox, Label) rather than acting together as a whole (although this doesn't have to be the case).
UserControl's are usually easier for people unfamiliar with WPF as they can be visually designed.
My suggestion would be to start off with a UserControl. You can always refactor this into a custom control at a later date as you become more familiar with the way WPF works. Creating your control as a custom control will require knowledge of ControlTemplates and Styles as you will need to provide your own to define a look and feel for your control.
When all is said and done, as long as the control behaves correctly, it doesn't matter which approach you use.
See this post for an example of two approaches to the same problem. The post author wanted a control which can present modal content in front of the primary content. The post author actually answered his own question by implementing it as a UserControl. I have added an answer to the post which creates the control as a custom control but both have the same end effect.
If you have a view-model and you wish to create a view for it use the User-Control.
If you need an autonomous control that has no specific view-model,
you probably need a custom-control.
If you find that the functionality you need as whole, already exist in other controls you need to override an existing control template.
(i.e: for a diamond shaped button - you need to override the button control template.)
Regarding attached-properties and attached-behaviors, those are useful when you have a control which you want to extend with more properties or you want it to behave slightly different than its default behavior.
In the provided case of the composition the OP described, it can be achieved with either user control or custom control. I would prefer a custom control since there is no specific view model provided, the "input" is only a property bound to an item collection.
Oh, and, I am sorry for slightly being late.
The best explanation is in the msdn. CustomControl is more a "virtual" name, there is no class called "CustomControl" in WPF, instead its meant creating a new class building on top of one of WPF control classes, like Control, ItemsControl and even more specific Controls like TextBox or Button.
For your specific case, a UserControl should be enough, creating a CustomControl is something that can easily be avoided. While its not a bad thing, a lot of people, especially beginners in WPF coming from WinForms tend to subclass more then necessary.
If this is somehow your first time building controls, I recommend UserControl as VS lets you design its interface more easily. Custom Controls are more powerful, but you have to CLEARLY separate your control's logic from its interface and this requires a bit more preparation.
You can easily Visually design CustomControl.
Create new UserControl (or Window). Create its xaml structure visually in Designer. Copy-paste body of the resulting xaml inside ControlTemplate of your new CustomControl (Eg. in generic theme file).
If I remember right, you are also able to visually design CustomControl template directly, in Blend.
Of course you can also instance the wip CustomControl in a Window and put the Window's Designer view as new panel above the control's xaml view in VisualStudio.
Some xaml bindings from style template don't show in Designer like this though, until I rebuild.
[ Imho GUI is mainly a visual matter and should not, and doesn't need to, be created in code. ]
Well to create a Custom control you need to implement it as a User control. Your own User control is called a Custom control. It is pretty simple.
UserControl is the base class for containing your custom content :
<UserControl>
Your custom WPF content
</UserControl>
I don't totally agree with the article. However in your case you need a UserControl that you can re-use latter in your UI.
I am currently developing a chat application in C# and I would like to know which form control allows to add text retaining control to each specific message to modify it later on when is required. I want this in order to be able to add a double tick when the message is received in the other side of the communication, pretty much like in "Whatsapp".
I've thought about an approach consisting on each message object firing events (like "sent", "received"..) when it changes that are listened by the corresponding form control that serves as the view, adding the above mentioned tick.
Any advice on how to achieve this goal? I've tried TextBox but Lines property force to have control os indexes and I want it to be completely event driven. Currently I stuck with DataGridView, however I've made little to no progress.
Thanks!
No one ready made Control I can think of will do the job, I'm afraid.
I would use a FlowLayoutPanel and add a Label for each chunk of text that gets added to the chat.
You can use MeasureString with a given width to get the height of the Label. (AutoSize should be off.)
The Labels would get the Width of the FLP and you could keep a List<> of the Labels with maybe a few meta data, like user, time etc..
Sounds like a good candidate for a ChatDisplay class to bundle the whole functionality!
Of course as the Labels are Controls you can add events to them as you like to communicate with the ChatDisplay or even with an outside communications object.. And the ChatDisplay class is free to implement whatever you need anyway. If necessary you can wrap the Labels in a ChatItem class, too.
Much more extensible than digging into a DGV to force it into doing things it was not meant to do..
I am writing a windows forms application that has a lot of textboxes. I want to add a label or a caption to the textbox, so that I don’t have to drag a lot labels onto the form and deal with positioning etc. So far I have found 2 possible ways to do this.
Create a user control with the label and textbox. How do I get the
control, label and textbox to size appropriately depending on the
text entered since the control will be reusable and different text sizes will be entered. How to get all the
properties and events of the textbox to remain the same.
Extend a normal textbox and add a string property called label or
caption, and show this property at the left of the textbox. I know
this can be done in Web.UI with CSS but is it possible in a winform
and how?
Any suggestions on how to do either of these?
Thanks.
You can create a UserControl that contains a label and a textbox. When you add the user control to your form, both the label and the textbox within will be added simultaneously. You can expose properties of the label and textbox to assign values at design or run time.
Using this method, you can add multiples of the user control to standardize the layout. As far as resizing the controls based on the text, you'll have to subscribe to events and change the sizing manually.
For example, you can subscribe to the TextChanged event of the label and the textbox. When the event fires, you calculate the size of the string and then adjust the width and position of the controls accordingly.
If you get to the point where you have too many textboxes, I would suggest switching to a DataGridView. The GridView component is very well suited for what you're describing, but of course it requires you to accept a grid layout.
One of the bonuses involved in using a GridView is hard to appreciate until you see it in action: it creates only one HWINDOW at a time (two if you're in editing mode). If you create Labels and TextBoxes all over your form, each one is registered with the operating system as an HWINDOW object. All those HWINDOW objects take time to display! In .NET 1.0, WinForms was so slow that dialogs with more than about two dozen controls were unusable. Even though .NET 2.0 is much better in this regard, but you'll still get significantly better performance by using a single control that manages lots of data, as opposed to lots of controls that each manage one piece of data.
Oh, and another option, if you like: you can also try a PropertyGrid. It has the advantage that it will also show help and allow you to create complex editing controls for each element.
if one part of one form of our app has many views - let's say depending on a radio button selection some where else on that form - then sometimes using a TabControl with some tabPages can be easy and helpful to show different views based on that selection.
so I still would like to have that "multiple views" functionality but I do not want to use a TabPage.... what would be the best replacement for that?
As far as I know, you'll have to code such a control yourself if you desire a lot of functionality. For regular operations, however, you can use this control I found on CodeProject: Multipane Control.
You could just have a Panel or something to define the area and then you could create one User control for each "view" that you want and then when the user selects a different radio button you just shows/hides the relevant user controls inside that Panel.
Or if the "views" are very simple, maybe the User controls would be overkill and you could just have a GroupBox for each view that you show/hide, but that can quickly create messy code if there are lots of event handlers etc.