I need to add a custom item to ListView control (like on the picture), is it possible ? And if it is, what's the best way to do it ?
I don't know that this is possible with Winforms. The list items in a System.Windows.Forms.ListView are System.Windows.Forms.ListViewItem objects contained in a strongly typed collection.
You could try to create a subclass of ListViewItem, but since that class inherits directly from System.Object and is not an actual windows form control, you might be borrowing trouble, as you would need to replicate all the functionality of the inheritance chain of an actual control.
Now, if you are not too far in to the project, you might consider looking at switching to WPF. The ListView in WPF uses controls as items, so you could easily create a usercontrol that you would use as your list items.
You might be able to find a control library with a control that gives you the functionality you want, but for the most part, the good libraries are commercial and can be prohibitively expensive for small shops and individual .
I did a quick google search for any library that offers this capability, but I could not find one that displayed custom controls.
Not sure if this is what you're after, but ListViewItems have a Tag property that can store custom data about each item.
http://msdn.microsoft.com/en-us/library/system.windows.forms.listviewitem.tag.aspx
How about creating a user control. In that case you can set your user controls at the top and listview below. Or are you trying to add these controls as items in the listview itself?
Related
I have a listbox that is databound to a List with a bindingsource, what I would like to obtain is that the listbox only shows certain object properties like for example firstName,lastName instead of firstName,lastName,Address,Country,...
How could I manage this?
I'm using winforms.
What about create another type which will be your exact view model and use list of this type?
my last project was a big project in winforms,and i was told that the data bound controls effectively reduce the overall performance of the application.
so the whole group had to work programmatically when adding data to a control,let it be datagrid,combo box,or any other windows control.
i would suggest you do the same too,Adding data to your Controls using code.that way you also decide what you want your clients to see and whatnot.
i would also suggest you take a look here :
how-might-i-add-an-item-to-a-listbox
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.
My program will prompt the user for a number, i.e. 25. The program will then start the "main form" with 25 controls (textbox). The 25 (or whatever number) of textboxes (or whatever control) will need to be formatted evenly. I will also need to be able to retrieve the text (or another property if I use another control) in order, from left to right and up to down. What is the best method of approaching this?
Using WPF MVVM. In a .XAML file, create a DataTemplate with the DataType of a ViewModel that will provide the binding for your TextBoxs, lets call this the TextboxViewModel. Then using a ItemsControl element with an ItemsSource of TextboxViewModel. You'll be able to instantiate as many TextBoxs as you want and be able to get the result by browsing through your list of TextboxViewModel.
Supposing you are using Windows Forms here.
Dynamically create the X controls and add them to the Controls collection of your form. To ease the access to them you can store their reference in a List and set some event handlers too, depending on your needs. You just need to calculate their positions while you add them.
If WinForms, this is exactly what the FlowLayoutPanel is for. Just add the controls to it and they will arrange themselves automatically, wrapping down to the next row as needed. As Mihai already suggested, you could also keep reference to those controls in a List.
Another option would be to use a TableLayoutPanel. It's a little more difficult to learn and use, but is much more flexible and powerful.
So what I am trying to do is to have a set UI with certain controls, and I want to have some class instance to fill in the values.
For instance:
Classes that can populate the UI:
Sharpen, Blur, Smear, ... : FilterBase
So whenever the user creates an instances of the above classes, I want to automatically fetch the values based on the UI controls, by using the class instance.
The UI has items like:
.Name (TextBox)
.Amount (NumericUpDown)
.Decay (NumericUpDown)
So if the current instance is s = new Sharpen(), I want to get s.Name to fill out UI.Name.
How do I do this in the best possible way? Elegancy, clarity, performance wise, etc.
I am gonna use reflection, but how do I store the instance of the object (Sharpen, ...) and be type safe? Should I use an System.Object instead? Or T?
public partial class ParamsUI
{
T CurrentFilter (?)
...
}
Also if I use T, how will I know what to cast it to?
Is there a better way?
Since this is using Windows Forms, the most flexible option would probably be to just use the Windows Forms PropertyGrid directly.
You can do a lot of work to customize the look and feel of this. See Getting the Most Out of the .NET Framework PropertyGrid Control for details.
Edit:
If you want to have a very flexible, easy option, and WPF is an option (hosted within an ElementHost), you could consider using WPF.
With this, you could host a UserControl containing nothing but a resource dictionary and a ContentControl.
You could then make a custom XAML file for each item you want to edit, and setup a data template in the resources specifying the mapping of which user control (xaml) to use for each element you want to edit. You can then just set the element to the user control's "DataContext" in code, and it will automatically wire everything up and "just work".
I would like to store and display a list of complex items. Each (graphic) item has to display an image, a list of color chips, a label and an index (a letter). User would also be able to zoom within each item, to show details of the image (on mousewheel),
Items would be presented in a vertical list, scrollable and resizable.
Language is C#, .net2.0, or 3.5 only if necessary.
I'm think about using custom UserControls for items (each one composed of a PictureBox, 2 Labels and a custom UserControl to display color chips).
For the list, I really don't know what to choose between a ListBox, a ListView, or a DataGridView, or another one I don't know yet.
I basically would go for a ListBox for its simplicity. Could you help me clarifying the advantages of using other lists?
If you expect to have a large number of these items, I strongly recommend that you do NOT make each one a UserControl. This is doubly important if you intend to localize and globalize the application at some point. The creation of these items will hinder performance.
Instead, take a lighter weight approach so that the items don't have the overhead of a full-blown control. Assuming that each item will be rectangular, you could easily create a UserControl for painting them, including a scrollbar to scroll.
in your case a custom (third party) list control seems to be the way to go. ListBox, a ListView or DataGridView are rather too limited given your requirements.
Regards,
tamberg
Thanks for your answers. It's very helpful to me.
I'm sorry I didn't mention that the list and its items have to manage drag-dropping with other controls. Then, I suppose that items have to be separate controls. Also, list would be dynamic and would not contain more than 30 items.
So, if I understand your advices, I should create a custom UserControl for the list and one for the item.