I have several TabControls defined in my XAML. I would like my ViewModel to be aware of the TabItem name or the index of the TabItem that is selected.
I also have a ScrollViewer that i would like to always scroll to the bottom when ever a button is pressed.
I should be able to solve both of the above issues if i could somehow get access to the elements in my code.
How can i acheve something like this:
var tabIndex = this.GetElement<TabControl>("NameOfSomeTabControl").SelectedIndex;
var scrollViewer = this.GetElement<ScrollViewer>("NameOfSomeScrollViewer");
scrollViewer.VerticalScrollBarValue = scrollViewer.VerticalScrollBarMaximum;
Edit: code for xaml, viewModel code
Edit 2:
Looks like i am able to get the instance of the element from the window class, however i'm still not sure how to pass the reference to the ViewModel.
Edit 3: I can achieve the scroll viewer going to the bottom automatically using the code below. however, once that method is invoked it seems like the scrolling gets disabled.
var tbRaw = this.Get<TextBlock>("tbRawOutput");
tbRaw.PropertyChanged += (s,e) => {
var svRaw = this.Get<ScrollViewer>("svRawOutput");
svRaw.Offset = new Vector(svRaw.Offset.X, svRaw.Extent.Height -svRaw.Viewport.Height);};
An easier way to do this might be to use the DataContextChanged event handler in your main Window class:
public MainWindow()
{
InitializeComponent();
DataContextChanged += (object sender, EventArgs wat) =>
{
// here, this.DataContext will be your MainWindowViewModel
};
}
Then you can attach more event handlers/use getters and setters on the view model from the Window
Related
I made a simple button, but when i click outside of win form my button getting a black border. By the way i set BorderSize to "0" and it works great while i clicking inside of my form.
this.button.FlatAppearance.BorderSize = 0;
That's how it looks like.
it seems a focus problem. Try to reset the focus when the cursor leave the control.
Add these lines of code to your forms load event.
btn.FlatStyle = FlatStyle.Flat;//You can also use the popup flat style
btn.FlatAppearance.BorderColor = btn.Parent.BackColor;
btn.FlatAppearance.BorderSize = 0;
One simple workaround is to set the FlatAppearance.BorderColor of the Button to its Parent.BackColor:
this.button1.FlatAppearance.BorderColor = this.button1.Parent.BackColor;
You could set this Property subscribing to the ParentChanged event (or overriding OnParentChanged, if it's a Custom Control) if the Control can be assigned to another parent at some point.
You can also perform the same operation in batch, using the HandleCreated event and have all the Buttons (with FlatStyle = FlatStyle.Flat) subscribe to the event in the Form's constructor:
public Form1()
{
InitializeComponent();
foreach (Button button in this.Controls.OfType<Button>().Where(btn => btn.FlatStyle == FlatStyle.Flat))
{
button.HandleCreated += (s, e) => {
button.FlatAppearance.BorderColor = button.Parent.BackColor;
};
}
}
I have a problem with WPF binding. I have frmBill.xaml Window with two usercontrol like that:
<materialDesign:TransitionerSlide OpeningEffect="{materialDesign:TransitionEffect SlideInFromRight}">
<materialDesign:TransitionerSlide.BackwardWipe>
<materialDesign:SlideWipe Direction="Right"/>
</materialDesign:TransitionerSlide.BackwardWipe>
<materialDesign:TransitionerSlide.ForwardWipe>
<materialDesign:SlideWipe Direction="Left"/>
</materialDesign:TransitionerSlide.ForwardWipe>
<local:ucBill_Information/>
</materialDesign:TransitionerSlide>
</materialDesign:Transitioner>
</Grid>
And I have two ViewModel as ucDeclarationViewModel.cs and ucBill_ViewModel for this. And using Thread with claim based to bind data between this by using a button click event (I got it), but I can not bind data from VM to V (Using prism). I know my issue, but I dont know how to solve it :(. Please help me.
private ucBill_InformationViewModel _ucBlvm;
public ucBill_InformationViewModel ucBIvm { get => _ucBlvm; set => _ucBlvm = value; }
public ucBill_Information()
{
InitializeComponent();
this.DataContext = ucBIvm;
}
i already searched few stackoverflow threads related thisbut i have problem in code plz review my code and tell me where is the problem i am stuck and do not where is the problem i am new here please help me out
public partial class MainWindow : Window
{
Grid MainGrid = new Grid();
public MainWindow()
{
InitializeComponent();
}
private void button_Click(object sender, RoutedEventArgs e)
{
TextBox dynamicTextBox = new TextBox();
dynamicTextBox.Text = "Type Partnumber";
Grid.SetRow(dynamicTextBox, 1);
Grid.SetColumn(dynamicTextBox, 0);
this.MainGrid.Children.Add(dynamicTextBox);
}
}
By using the button_Click event you are adding the dynamic TextBox to the MainGrid and that code looks fine. But the problem is that this.MainGrid is not in the Present UI, its similar to the dynamically created TextBox, since you ware defined it in the code-behind(see the definition above the constructor Grid MainGrid = new Grid();).
Consider that canContainer is a canvas defined in the xaml as like the following,
<Canvas Height="319" Margin="0"
Width="517"
Name="canContainer"/>
To overcome this you can choose any of the following method.
1.Add The MainGrid to the UI. it will add the grid to the canvas, keep in mind the dynamic textBox already added to the Grid.
which means the code should be like this -->
this.canContainer.Children.Add(MainGrid);
2.Add dynamicTextBox to any other parent which is present in the UI.
this.canContainer.Children.Add(dynamicTextBox);
You you are using this method then need not to define and adding MainGrid
in my application i want to implement an options dialog like you have in VisualStudios if you go to Tools->Options in the menubar. How can i do this? My first idea was to use pages and navigation but maybe there's an easier approach?
It's probably not the easiest way but I wrote this snippet that match your goal and it's a good exercise.
In an empty Windows Forms project add a ListBox (listBox1) and a Panel (panel1). Then create 2 UserControls (UserControl1 and UserControl2), these will be the content that is shown when you click the list.
In your Form1 class we create a ListItem class that will contain your menu options as such:
public partial class Form1 : Form
{
public class ListItem
{
public string Text { get; set; }
public UserControl Value { get; set; }
public ListItem(string text, UserControl value)
{
Text = text;
Value = value;
}
};
...
}
After that you add items to the ListBox right after InitializeComponent() in Form1:
public Form1()
{
InitializeComponent();
listBox1.DisplayMember = "Text";
listBox1.ValueMember = "Value";
listBox1.Items.Add(new ListItem("Item1", new UserControl1()));
listBox1.Items.Add(new ListItem("Item2", new UserControl2()));
}
This will make it so when you use listBox1.SelectedItem it will return an object that you can cast to a ListItem and access the associated UserControl.
To make use of this behaviour, go to designmode and double-click the ListBox, this'll add code for the SelectedIndexChanged event. We use this event to display the UserControl in the Panel panel1. This will clear any old Panel content and add a selected UserControl:
private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
panel1.Controls.Clear();
UserControl control = (listBox1.SelectedItem as ListItem).Value;
if(control != null)
{
panel1.Controls.Add(control);
control.Dock = DockStyle.Fill;
}
}
I suggest you try adding a button or something to differentiate the UserControls and play around. Have fun! :)
You should create a new Window and show that as opposed to create a page and navigate to it. Then you would call .show() on the new window for it to show.
Then you would change the look of the new window to however you want, the same as editing pages.
If you build your options into a full object model that matches the structure of the options window, then the best way is to use whatever navigation-aware UI binding that your MVVM toolkit uses. The options window would start off as a new root level window to which you would bind the root of your options data model.
So, in short think of the options dialog as a mini-application that uses the same structure as your main MVVM application, but with a different data model root.
If you plan to allow the user to cancel the changes to the options, then you would want your options data model to be clonable so that you can populate the options window with the clone and then swap out the real options with the new data if the user presses OK on the options window. If they select cancel you can just throw the cloned object away and destroy the window.
I have a requirement to focus on a specific textbox when a new view is loaded.
The solution was to add this line of code to the OnLoaded event for the view:
Dispatcher.BeginInvoke(() => { NameTextBox.Focus(); });
So this worked for one view, but not another. I spent some time debugging the problem and realized that the new view I was working on had a BusyIndicator that takes focus away from all controls since the BusyIndicator being set to true and false was occuring after the OnLoaded event.
So the solution is to call focus to the NameTextBox after my BusyIndicator has been set to false. My idea was to create a reusable BusyIndicator control that handles this extra work. However, I am having trouble doing this in MVVM.
I started by making a simple extension of the toolkit:BusyIndicator:
public class EnhancedBusyIndicator : BusyIndicator
{
public UserControl ControlToFocusOn { get; set; }
private bool _remoteFocusIsEnabled = false;
public bool RemoteFocusIsEnabled
{
get
{
return _remoteFocusIsEnabled;
}
set
{
if (value == true)
EnableRemoteFocus();
}
}
private void EnableRemoteFocus()
{
if (ControlToFocusOn.IsNotNull())
Dispatcher.BeginInvoke(() => { ControlToFocusOn.Focus(); });
else
throw new InvalidOperationException("ControlToFocusOn has not been set.");
}
I added the control to my XAML file with no problem:
<my:EnhancedBusyIndicator
ControlToFocusOn="{Binding ElementName=NameTextBox}"
RemoteFocusIsEnabled="{Binding IsRemoteFocusEnabled}"
IsBusy="{Binding IsDetailsBusyIndicatorActive}"
...
>
...
<my:myTextBox (this extends TextBox)
x:Name="NameTextBox"
...
/>
...
</my:EnhancedBusyIndicator>
So the idea is when IsRemoteFocusEnabled is set to true in my ViewModel (which I do after I've set IsBusy to false in the ViewModel), focus will be set to NameTextBox. And if it works, others could use the EnhancedBusyIndicator and just bind to a different control and enable the focus appropriately in their own ViewModels, assuming their views have an intial BusyIndicator active.
However, I get this exception when the view is loaded:
Set property 'foo.Controls.EnhancedBusyIndicator.ControlToFocusOn' threw an exception. [Line: 45 Position: 26]
Will this solution I am attempting work? If so, what is wrong with what I have thus far (cannot set the ControlToFocusOn property)?
Update 1
I installed Visual Studio 10 Tools for Silverlight 5 and got a better error message when navigating to the new view. Now I gete this error message:
"System.ArgumentException: Object of type System.Windows.Data.Binding cannot be converted to type System.Windows.Controls.UserControl"
Also, I think I need to change the DataContext for this control. In the code-behind constructor, DataContext is set to my ViewModel. I tried adding a DataContext property to the EnhancedBusyIndicator, but that did not work:
<my:EnhancedBusyIndicator
DataContext="{Binding RelativeSource={RelativeSource Self}}"
ControlToFocusOn="{Binding ElementName=NameTextBox}"
RemoteFocusIsEnabled="{Binding IsRemoteFocusEnabled}"
IsBusy="{Binding IsDetailsBusyIndicatorActive}"
...
>
Update 2
I need to change UserControl to Control since I will be wanting to set focus to TextBox objects (which implement Control). However, this does not solve the issue.
#Matt, not sure
DataContext="{Binding RelativeSource={RelativeSource Self}}"
will work in Silverlight 5, have you tried binding it as a static resource?
Without a BusyIndicator present in the view, the common solution to solve the focus problem is to add the code
Dispatcher.BeginInvoke(() => { ControlToFocusOn.Focus(); });
to the Loaded event of the view. This actually works even with the BusyIndicator present; however, the BusyIndicator immediately takes focus away from the rest of the Silverlight controls. The solution is to invoke the Focus() method of the control after the BusyIndicator is not busy.
I was able to solve it by making a control like this:
public class EnhancedBusyIndicator : BusyIndicator
{
public EnhancedBusyIndicator()
{
Loaded += new RoutedEventHandler(EnhancedBusyIndicator_Loaded);
}
void EnhancedBusyIndicator_Loaded(object sender, RoutedEventArgs e)
{
AllowedToFocus = true;
}
private readonly DependencyProperty AllowedToFocusProperty = DependencyProperty.Register("AllowedToFocus", typeof(bool), typeof(EnhancedBusyIndicator), new PropertyMetadata(true));
public bool AllowedToFocus
{
get { return (bool)GetValue(AllowedToFocusProperty); }
set { SetValue(AllowedToFocusProperty, value); }
}
public readonly DependencyProperty ControlToFocusOnProperty = DependencyProperty.Register("ControlToFocusOn", typeof(Control), typeof(EnhancedBusyIndicator), null);
public Control ControlToFocusOn
{
get { return (Control)GetValue(ControlToFocusOnProperty); }
set { SetValue(ControlToFocusOnProperty, value); }
}
protected override void OnIsBusyChanged(DependencyPropertyChangedEventArgs e)
{
base.OnIsBusyChanged(e);
if (AllowedToFocus && !IsBusy)
{
Dispatcher.BeginInvoke(() => { ControlToFocusOn.Focus(); });
AllowedToFocus = false;
}
}
}
To use it, replace the BusyIndicator tags in your xaml with the new EnhancedBusyIndicator and add the appropriate namespace.
Add a new property, ControlToFocusOn inside the element, and bind it to an existing element in the view that you want focus to be on after the EnhancedBusyIndicator disappears:
<my:EnhancedBusyIndicator
ControlToFocusOn="{Binding ElementName=NameTextBox}"
...
>
...
</my:EnhancedBusyIndicator>
In this case, I focused to a textbox called NameTextBox.
That's it. This control will get focus every time we navigate to the page. While we are on the page, if the EnhancedBusyIndicator becomes busy and not busy agiain, focus will not go to the control; this only happens on initial load.
If you want to allow the EnhancedBusyIndicator to focus to the ControlToFocusOn another time, add another property, AllowedToFocus:
<my:EnhancedBusyIndicator
ControlToFocusOn="{Binding ElementName=NameTextBox}"
AllowedToFocus="{Binding IsAllowedToFocus}"
...
>
...
</my:EnhancedBusyIndicator>
When AllowedToFocus is set to true, the next time EnhancedBusyIndicator switches from busy to not busy, focus will go to ControlToFocusOn.
AllowedToFocus can also be set to false when loading the view, to prevent focus from going to a control. If you bind AllowedToFocus to a ViewModel property, you may need to change the BindingMode. By default, it is OneTime.