I am new to Wpf. One UserControl (Wpf UserControl) is added to
the DockPanel and in some action O replaced the first UserControl
with another UserControl in DockPanel dynamically. But the first
UserContorl remains visible and the second UserControl in not showing
in DockPanel.
I don't know the correct behavior of how I can be
loaded dynamically. I added this code (this code is executed well)
but it doesn't reflect the action to display "CtlAddEmployee"
control in Dockpanel.
CtlAddEmployee frm2 = new CtlAddEmployee(str);
DockPanelInRibbon.Children.Clear();
DockPanelInRibbon.Children.Add(frm2);
For full details how it is working is asked in my previous question
in detailed way:
Loading another userControl in wpf Ribbon Window when the we click on DataGrid row
Please provide the solution for this.
yaa here i need to refer old object but not the new created object for the corresponding class reference...
For that better to use parameterized constructors..
Related
I am new to WPF.
I have requirement to create a window (as below. Ignore background color. Just gave color to distinguish different panels). On click on next, center panel (with frame) will load another page/user control. This is working fine.
Now I need to validate data/input of the form when user clicks Next. If everything is fine, next control should load. But I am unable to get controls from frame to Mainwindow.
Can someone please help me on how can I access controls of page/usercontrol from Main Window. I have a label after each control which will show error message if values are not not provided or are incorrect.
If you are using MVVM Pattern, On your next click, you can raise an event from the usercontrol View Model and get some response back to the Main Page's View Model where your Next code resides.
OR
You can access the Usercontrol's Datacontext in Main Page's View Model, Cast it to your Usercontrol's View Model. Take the information and just do your validation.
Hope this will help you...
I have a MainWindow in my WPF app.
This MainWindow has a menu on the left and when a menu option is selected a UserControl is loaded on the right.
This is similar to Master Pages in asp.net
What I want to do now is to have a modal window show from the UserControl which will only allow the user to interact with the modal window.
I have seen examples of the Main Window showing a modal window (http://www.codeproject.com/Articles/36516/WPF-Modal-Dialog) but not sure on how to load this from a UserControl.
There's this: dialogs and mvvm but this is the best example I've seen of dealing with it: mvvm and closing forms
The first link I've not used and stumbled across while looking for the second link to post that here. The second link has two downloads, you can ignore the _service download, it's basically the same.
One way in WPF is this method
Add a new Window to the project.
Add other controls onto the window as needed.
In XAML name the window such as x:Name="MyWindow"
Put on Dependency properties on the window and have each of the controls bind to the window's data context such as {Binding MyText, ElementName=MyWindow}. (Note I still use, even for WPF these Visual Studio code snippets to add different dependency properties, these save time for a very redundant operations of adding them: Silverlight Snippets.
In the location where you want to launch the model dialog use this example:
Example:
var about = new About(); // Create the new window
// I've added a CompanyName dependency property.
about.CompanyName = "OmegaMan Industries";
about.ShowDialog();
A while I go, I made a demo application with Expression Blend.
My first screen is a big selections of Buttons, so when user click on any of button, it goes to the MainView.
Then in the MainView, I have a list of Menu items that user can click and shows up its corresponing DisplayView. (Appointment Menu Item will shows up AppointmentView etc).
Everything is good, I can click the MenuItem, the Views shows up with animation and transition effects.
But the thing is, with creating in Expression Blend, the MainView, Menu, AppointmentView etc every thing is predefined in the XAML. So when user load the first screen has to load everything into memory.
Now thinking of it, shouldn't the MainView etc be dynamically add into the screen?
How do I do it with Expression Blend? Or the only way to do is just....do it in code-behind myself (writting StoryBoard etc for the dynamic add/remove controls?)
If there is any example/tutorial of doing it, it will be great.
I guess you have very limited possibilities to conditionally load or unload controls exclusively in Blend without writing code-behind.
In general an opening tag in XAML is equivalent to a parameter-less constructor of some class object. As soon as you write the tags your are instantiating an object but that doesn't mean that it's visual appearance is loaded into memory. This only happens when the control is actually shown on the screen.
In my opinion the leanest way to control the appearance of some control is to use a single-child control. Take a Border control for example and add the user control you want to conditionally load to its child property, so you can decide for example whether to load or unload a control.
But unfortunately I think you have to do this in code as well. Take this easy code snippet:
// either instantiate in code or use from markuup
Border myBorder = new Border();
// the control you want to conditionally appear and disappear
UserControl myUserControl = new UserControl();
myBorder.Child.Add(myUserControl);
Of course a much more sophisticated approach is to use Grids. Here you have to use attached properties to add or remove child elements:
// either instantiate in code or use from markuup
Grid myGrid = new Grid();
// the control you want to conditionally appear and disappear
UserControl myUserControl = new UserControl();
// set the target position inside the Grid via the Grids attached properties
Grid.setRow(myUserControl, 1);
Grid.setColumn(myUserControl, 0);
// actually add the control
Grid.Children.Add(myUserControl);
Although I am pretty sure you were aware of all of that I am hoping it helped a bit :)
I searched this site and i found 2 Links
how to load wpf usercontrol in MVVM pattern
MVVM-Light: Load UserControl into Window
but still i cant find the answer to my problem and this link
MVVM-Light Locator Pattern and Reusable UserControl
i Didn't Understood.... so here is i am stating my problem which might help others struggling like me ......
I have a MainWindow which has 2 parts one has a TreeView(a
UserControl) and the other Displays different user controls(named DisplayPanel).... just like windows Explorer.
The Display Panel on the Right side will display different user controls on Clicking nodes of tree view.
and my TreeView is Itself a user Control.
How can i make this composite UI Work using MVVM. Also I am planning to use MVVM light Toolkit. Does this have something that can help...
An Example will be great
Thanks... :)
Edit
My TreeView in a UserControl I made a dependency property in the UserControl which catches the selected Item fo the tree view so that i can use this dependency property to populate the required view in the "MainView" ContentControl binding....as you advised me in the comments. Everything is till now
Problem is that i want to display data contained in the the selected item and i cannot set the DataContext of the UserControls(which will be displayed in right hand side) to the selected item as then i will not be able to use my view model for the respective usercontrol for commands and other operations
I tried to solve this too.... i used the Mediator (Messenger) in my TreeViewUserControl view model to send a Message to the Usercontrol's(the one that i need to display) view model . Message will be passed whenever the item is selected in the tree view. and message contains the selected node. I forgot to mention i set the datacontext of the UserControl to its view model so that i could display data
But using this approach the problem is that when the I click a type of node for the first time the data is not populated but if the same type of node is clicked again its populated. What’s happening is that UserControls object is availabe when the the tree item is clicked for the first time and Mediator sends the message. So Mediator is not able to pass the message to the userControl view model.....
I totally do not have ne idea to solve this further.... is my way if displaying user control right or I should do something that else....totally confused.....
You could try defining a DataTemplate for each type in the TreeView's ItemsSource and instead of having a specific UserControl on the right side, just bind to the TreeView's SelectedItem. Alternatively, you could use a DataTemplateSelector.
Edited for OP's Edit
Did you do this?
MainWindow has TreeView whose ItemsSource=Binding MainVM.Items.
MainWindow has ContentControl whose Content=Binding TreeView.SelectedItem.
Somewhere in project, have ResourceDictionary where each possible type in MainVM.Items has a DataTemplate defined?
Which ViewModel (MainVM or ItemVM) are you trying to use and why can't you use it?
I have a custom UserControl that I created as a navigation menu that parses an xml file and populates itself with hyperlink buttons. So basically my control is an empty stackpanel, and when it's loaded it adds hyperlinkbuttons as children to the stack panel.
In my application I just add a <myLibrary:NavigationMenu links="somexml.xml" />
The problem is that I want to be able to style the hyperlinkbuttons and the stack panel differently for every application. What is the best way to do this.
In the code behind for the control, create a DependencyProperty of type Style for both HyperlinkStyle and StackPanelStyle. Then when you create the items apply the correct styles too them.
Take a look at MSDN
The article is a good starting point for writing stylable controls.