At our work we have a controversy going on where some people want to create user controls that combine frequently used controls like a label and a text box, or a label and a image control. That is, something like this:
<StackPanel Orientation="Horizontal">
<Image Source="/Someimage/Somewhere.gif"/>
<Label>Some text, hyperlink, or other content</Label>
</StackPanel>
and use it like this
<ImageLabel
HeaderImageSource="/Someimage/Somewhere.gif"
>
Some text, hyperlink, or other content
</ImageLabel>
The question is if they are providing enough encapsulation and abstraction to merit a separate user control?
Yes, in my opinion this is sufficient to create a separate user control - if they form a logical component in your context. In the project I'm working on we do create user controls if we have grouped components like this we want to reuse.
The main benefit is that you get control of the structure and style of the component. Consider the case where you want to do a change somewhere. E.g. add a border around the image or add some style to your label. You don't want to browse the code to find all occurences of your repeated group of components. Instead - you'd like to update this one place only - namely in the custom component you've separated out.
Another advantage is if you want to bind the components to the same object. Then you can bind your ImageLabel to the object instead, and your components can bind directly to properties within this object in a nice and clean way.
Note: I'm assuming that you actually want to reuse this component and want it to be structured and styled the same way all through your application. I would never create a user control this simple for using only once.
Seems a little bit overkill to create a UserControl for three controls; I'd consider whether or not it saved me time and effort rather than encapsulation/abstraction.
Related
I've got a massive UI that I'm designing. The way that my employer wants it, there are at least 100 labels. Now, I've always thought that in cases like this, breaking up the UI into smaller custom controls was the ideal way to go. However, someone recently told me that custom controls are really only for code re-use. What is the actual suggested practice for this?
EDIT
The finished form will look like this:
Now, I'm using WPF for the UI, and I'm thinking of breaking this down into smaller bits.
Based on your image i see some repetitions, each of this repetitions could be a custom UserControl
But it depends on the usability is it easier to write a custom UserControl so do it but if it would reduce the readability of your code and it also adds additional complexity don't do it
here are an example of what could be separate UserControl's
the green ones are possible useful encapsulations of logic
the orange ones maybe need some not market stuff (don't know enough about your software)
the red ones are the maybe's based on the intern use (from the visual part they are repetitions so the should custom UserControl)
Since your UI is read-only, I'd suggest using a grid.
Are you new to WPF? To break the View into bits WPF offers you CustomControls and UserControls. They are two very similar things yet completely different from each other. CustomControls are Buttons, Labels, TextBoxes, DataGrids...etc. They are basically simple stand-alone controls. UserControls are groups of stand-alone controls serving a purpose such as example a Button and a ComboBox next to each other so user can select something in ComboBox and confirm that by clicking the Button.
If you wish to display data from database I suggest you DataGrid which will give you a table-alike look with rows and columns and all that. If you wish to place few buttons next to DataGrid on which the user may click to insert a new row or to edit a certain cell then I suggest you to wrap all that with a UserControl which you can reuse in other places where you have to display and change data from database too.
You should be using a datagrid and can customize its template to render individual cells as Textblock (lighter version of Label) from a rendering perspective. The main difference between Textblock and Label is very minor things such as access keys and disabled state behavior. But from a WPF object hierarchy - Textblocks are much lighter. But besides that point - from your employer perspective - once you have customized the grid template and render them (so as they look as textblocks/labels) - your employer should have no problems.
Also as somebody suggested above - if you want to logically break sections of the UI since they maybe coming from a different table in db - then User controls is the way to go (for maintainability of code)
Let me know if you are looking for more technical details or need help further technically.
There is nothing wrong in making and using custom controls or user controls or defining some data templates which will be reused depending on how your data is organized.
For sure the UI looks pretty messy and some sort of grid should be used with templates for example where there is similar data. I also have the suggestion and first think about the data and the functionality before starting and let the UI be driven by that. For sure you will the reuse controls/templates. If you think in front on the model and behavior the UI can afterwards more easily changed.
Create your viewmodel correctly, implement the functionality in commands, use bindings, after that the UI will come naturally, reuse controls, use several grids, make the UI more user friendly using several regions, tabs, windows or anything that makes the user more comfortable.
I need to show a similar-looking dialog in two different places in my application, one place as a modal dialog box and one place embedded into another menu.
From my limited understanding of WPF, it looks like Styles would allow me to write a single UserControl and customize its colors and fonts for both scenarios. However the changes are a bit more extensive, some of the element positions (for example, TextBox) are in different relative positions.
I am not sure if this can be done with Styles, or if there is a more appropriate way to do this in WPF. Worst case, I can write two completely different UserControls, but that is very bad in terms of maintainability so I'd like to avoid it.
Sure you can do it with styles/templates. Just give each of the styles a key and use the key to access the right style at the right place:
<YourUserControl Style="{StaticResource firstStyle}"/>
If you use a pattern like MVVM (I prefer MVVM Light) this is quite simple to do. You would write one ViewModel that captured all the data and behavior you wanted to expose and then create two views the way you want them, both using the same view model.
This scenario is one of the core intents behind the MVVM pattern. You're right that it is "bad" to write the behavior/plumbing twice, but the views are different, so you're not violating any re-use there.
I wanted to know which one amongst Style and UserControl would be better to use in WPF?
For example:
I have created an image button in two different ways.
One uses Style and ContentTemplate property is set.
It uses one other class with dependency properties.
The other way is I have created a UserControl which has a button and its content property is set.
The file UserControl.xaml.cs also contains the dependency properties.
For Code details see the answers of this question:
Custom button template in WPF
Which one would be better to use? In which scenario should one go for Style or UserControl or any CustomControl?
Styles are limited to setting default properties on XAML elements. For example, when I set the BorderBrush , I can specify the brush but not the width of the border. For complete freedom of a control’s appearance, use templates. To do this, create a style and specify the Template property.
Styles and templates still only allow you to change the appearance of a control. To add behavior and other features, you’ll need to create a custom control.
For example,
To create a button like a play button use styles and templates, but to create a a play button which will change its appearance after pausing it use UserControl.
For this type of thing I would go with Style, even though I'm not really adept with graphical tools. I tend to produce a basic, boring style that I can get started with and then prettify it once the application functionality has been verified.
The nicest thing about WPF is being able to distance much of the graphical look, feel and behaviour away from the code.
This allows you to change the style of your application without revisiting the code and indeed means that you can change styles on the fly at runtime.
There is an awkward line to tread with regards to how much behaviour is placed within the XAML and how much is placed within the code. A rough guide would be to decide on what behaviour must always be present within the UI and place that in the code, everything else place within the XAML.
Think of the code as being an abstract class with defined interfaces and the XAML Styles as being classes based on that class and you'll get an idea of what I mean.
Conversely, I know that people who are far more adept at the GUI work prefer to put more functionality in the XAML and others who prefer the code side, because they find the GUI work slow or difficult.
When thought of that way you'll see that there's never really a right or wrong answer, just better solutions that suit your skills.
I am trying to come to a working understanding of how databinding works, but even after several tutorials I only have a basic understanding of how databinding works. Thus this question might seem fundamental to those more familiar with silverlight. Even if it is trivial, please point me to some tutorial that deals with this problem. All that I could find simply solved this via adding the data binding on a parent page.xaml (that i must not use in my case).
For the sake of this example let us assume, that we have 5 files:
starter.cs
button1.xaml + codeBehind
button2.xaml + codeBehind
The two buttons are generated in code in the starter(.cs) file, and then added to some MapLayer
button1 my_button1 = new button1();
button2 my_button1 = new button2();
someLayer.Children.Add(my_button1);
someLayer.Children.Add(my_button2);
My aim is to connect the two buttons, so that they always display the same "text" (i.e. my_button1.content==my_button2.content = true;). Thus when something changes my_button1.content this change should be propagated to the other button (two way binding).
At the moment my button1.xaml looks like this:
<Grid x:Name="LayoutRoot">
<Button x:Name="x_button1" Margin="0,0,0,0" Content="{Binding ElementName=x_button2, Path=Content}" ClickMode="Press" Click="button1_Click"/>
</Grid>
But everthing that i get out of that is a button with no content at all, it is just blank as the binding silently fails.
How could I create the databinding in the context I described? Preferably in code and not XAML ;)
Thanks in advance
The chunk of documentation you need to read is this: XAML Namescopes
Your button1 xaml has a binding looking for an element with the name "x_button2". However in a real application there can be many controls which in turn have nested controls. All of these controls have all manner of UI elements some of which may have names.
It would be impossible to get anything done if all names throughout the entire application had be unique. Yet that would need to be true if it were for your button1 to be able to hunt down the existence of another control somewhere in the visual tree outside of that which it actually knows (its own xaml).
Hence each loaded Xaml document exists in its own "namescope" and the search for other elements with other names is limited to that "namescope".
The are various solutions to this problem depending on what you real requirements are as opposed to the simplified problem in your question.
Typically you give each of your controls a DependencyProperty to which the inner button Content property binds. In "MapLayer" as call it, could then bind the propert on one of your button controls to the other.
Trying to implement what I thought was a simple concept. I have a user control (view) bound to a view model which provides a list of data. I have added toggle buttons to the usercontrol and would like to allow the user to use these toggle buttons to switch out which template is used to show the data. All of the templates used for the data work, and they are very different from one another so it's not just simple changes to a single template. I'd like to get this as much in XAML as possible.
Here's what I have now:
Where the data appears I have <UserControl Template="{StaticResource ListSwitchingControlTemplate}" />
In that control template I have all "sub templates" - really it's just all 3 representations with their visibility set to Collapsed. Then I use a data trigger on that control template to show the currently selected view. This works, but I noticed that all 3 representations get bound - they each act like they are active (and they are I guess).
I'd rather be able to truly switch the template at run time. I tried converting the containing user control to use a ContentTemplate for itself, but that just messes up all of the binding I have elsewhere. If only UserControls could use DataTriggers I'd be ok.
Any suggestions on how to cleanly go about getting this behavior. I have an idea that I'm just missing something simple.
Thanks,
Dave
you could do it via code?
http://www.switchonthecode.com/tutorials/wpf-tutorial-how-to-use-a-datatemplateselector ???
http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/4fd42590-8375-46d0-b7bc-6c217df0f0ba/
http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/dbbbb5d6-ab03-49a0-9e42-686fd41e0714
One way to do this would be to use a DataTemplateSelector.
Basically, you create a class that inherits from DataTemplateSelector and override its SelectTemplate virtual function. The return value from the function is the DataTemplate you want to use and in that function you have access to the object and its properties, which you can use to decide which template to select.
There is an example on MSDN here:
http://msdn.microsoft.com/en-us/library/system.windows.controls.datatemplateselector.aspx