Modify the visibility of a row via keyboard interaction in UWP application - c#

Here is my scenario. My table has fixed number of columns, say 2, and initially, it has only one visible row, but when the focus is on the last column of row 1 and the user press 'tab', row 2 will be made visible.
My problem is that I can't dynamically select the row I want to make visible because I have to specify its x:Name during compilation.
Below is my current work.
.xaml file
<StackPanel Orientation="Vertical">
<StackPanel Orientation="Horizontal" x:Name="SP1">
<TextBox Text="1-1"/>
<TextBox Text="1-2" KeyDown="showNextLine"/>
</StackPanel>
<StackPanel Orientation="Horizontal" x:Name="SP2" Visibility="Collapsed">
<TextBox Text="2-1"/>
<TextBox Text="2-2"/>
</StackPanel>
<!--the remaining rows...-->
</StackPanel>
.cs file
private int lastRowIndex = 1;
private void showNextLine(object sender, KeyRoutedEventArgs e)
{
lastRowIndex++;
string nextLineName = "SP" + lastRowIndex.ToString();
nextLineName.Visibility = Visibility.Visible; // which causes error because nextLineName is string instead of StackPanel
}
Besides, my current implementation is to create 50 rows and make the last 49 invisible initially, and I am open to any method to group all the TextBox more systematically or flexibly.
Thanks for reading.

You could give the parent StackPanel an x:Name or keep a reference to it if you create it dynamically:
<StackPanel x:Name="root" Orientation="Vertical">
<StackPanel Orientation="Horizontal" x:Name="SP1">
<TextBox Text="1-1"/>
<TextBox Text="1-2" KeyDown="showNextLine"/>
</StackPanel>
<StackPanel Orientation="Horizontal" x:Name="SP2" Visibility="Collapsed">
<TextBox Text="2-1"/>
<TextBox Text="2-2"/>
</StackPanel>
<!--the remaining rows...-->
</StackPanel>
...and then get a reference to a child StackPanel using the Children property and some basic LINQ:
private void showNextLine(object sender, KeyRoutedEventArgs e)
{
lastRowIndex++;
string nextLineName = "SP" + lastRowIndex.ToString();
StackPanel child = root.Children.OfType<StackPanel>().FirstOrDefault(x => x.Name == nextLineName);
if (child != null)
child.Visibility = Visibility.Visible;
}
How could I create a StackPanel dynamically?
Like this:
var sp = new StackPanel { Name = "SP3", Orientation = Orientation.Horizontal, Visibility = Visibility.Collapsed };
sp.Children.Add(new TextBlock { Text = "3-1" });
var txt = new TextBlock() { Text = "3-2" };
txt.KeyDown += showNextLine;
sp.Children.Add(txt);
root.Children.Add(sp);

I can't think of an easy way to do the first part of this (since you have 50 stack panels), but if you put all of them in a dictionary, then you could update them using just the key.
Here's the dictionary part done manually:
Dictionary<int, StackPanel> myStackPanels = new Dictionary<int, StackPanel>();
myStackPanels.Add(1, SP1);
myStackPanels.Add(2, SP2);
Then, here's what ShowNextLine would look like:
private void showNextLine(object sender, KeyRoutedEventArgs e)
{
lastRowIndex++;
// Modify the StackPanel whose key is lastRowIndex;
myStackPanels[lastRowIndex] = Visibility.Visible;
}

Related

UWP - get first child of Gridview

<GridView x:Name="MainGridStations" ItemsSource="{x:Bind Stations}" IsItemClickEnabled="True" ItemClick="GridView_ItemClick">
<GridView.ItemTemplate>
<DataTemplate x:DataType="local:Station">
<Grid x:Name="WantToSelectByCode">
<Grid Background="White" HorizontalAlignment="Center" Width="300" Height="200" VerticalAlignment="Center">
<Grid Background="#e4f0fc" Height="65" VerticalAlignment="Bottom" Opacity="0.8">
<TextBlock x:Name="StationName" Text="{Binding Name}" FontWeight="Bold" Foreground="#2c9a8b" HorizontalAlignment="Center" />
</Grid>
</Grid>
</Grid>
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
I'm trying to select a child by index of a dynamically filled gridview but what i've tried always returns null.
Like so for the first child for example:
var container = MainGridStations.ContainerFromIndex(0);
var presenter = VisualTreeHelper.GetChild(container, 0) as GridViewItem;
What am I doing wrong here?
You can get the corresponding GridViewItem from the method ItemsControl.ContainerFromIndex(Int32) directly and don't need to use the VisualTreeHelper to get it again.
var container = MainGridStations.ContainerFromIndex(0);
GridViewItem gridViewItem= container as GridViewItem;
gridViewItem.Background = new SolidColorBrush(Colors.Red);
The container have been the corresponding GridViewItem got from the index.
Note that: since your inner Grid have a Background="White" property configuration, you can delete the code to see the effect more obviously using my above code to change the gridViewItem.Background.
---Update---
You must get the GridViewItem after the items loaded. You can try the code in your GridView_ItemClick event handler or the page's loaded event hander. Also pay attention to my above note that to get more obvious effect, please delete the Background="White" in your above xaml code.
private void MainPage_Loaded(object sender, RoutedEventArgs e)
{
var container = MainGridStations.ContainerFromIndex(0);
GridViewItem gridViewItem = container as GridViewItem;
gridViewItem.Background = new SolidColorBrush(Colors.Green);
}
//get the item here
private void GridView_ItemClick(object sender, ItemClickEventArgs e)
{
var container = MainGridStations.ContainerFromIndex(0);
GridViewItem gridViewItem= container as GridViewItem;
gridViewItem.Background = new SolidColorBrush(Colors.Red);
//var presenter = VisualTreeHelper.GetChild(container, 0) as GridViewItem;
}

UWP Grid inside Datatemplate

I have a Pivot where I set the header in my Pivot.HeaderTemplate it is basically just showing Names of Books. In my Pivot.ItemTemplate I want to show a Grid which is build in my .xaml.cs but since the Grid is in my DataTemplate I can not access the Grid x:Name anymore in the code behind in .xaml.cs. books is a Collection of Books which contains a Name and a Title
MainPage.xaml
<Pivot ItemsSource="{x:Bind books}">
<Pivot.HeaderTemplate>
<DataTemplate x:DataType="local:Book">
<TextBlock Text="{x:Bind Name}"/>
</DataTemplate>
</Pivot.HeaderTemplate>
<Pivot.ItemTemplate>
<DataTemplate>
<Grid
x:Name="BooksGrid"
BorderBrush="Black" BorderThickness="1 1 0 0"
Margin="0 10 0 0>
</Grid>
</DataTemplate>
</Pivot.ItemTemplate>
Now I want to acces BooksGrid iny the code behind and actually create the Grid
MainPage.xaml.cs
public MainPage()
{
this.InitializeComponent();
}
private void DrawGrid()
{
//create columns of Grid
for (int i = 0; i < booksize.XProperties.Count + 1; i++)
{
BooksGrid.ColumnDefinitions.Add(new ColumnDefinition
{
});
}
BooksGrid.ColumnDefinitions[0].Width = GridLength.Auto;
}
....
Already here at BooksGrid.ColumnDefinitions.Add(...) I get the error that BooksGrid can not be found.
My DrawGrid works if I do not place the Grid definition in my DataTemplate and also outside myPivot. So the MainPage.xaml.csdoes not find it when the Grid is inside my DataTemplate
I've read that the solution might be that I have to acces the Grid instance that I want to work with, as soon as the DataTemplate gets loaded. But I do not know how to do that either.
EDIT PART to first solution:
I'm also using BooksGrid in another method
MainPage.xaml.cs
private void DrawBooksFront(Front front)
{
int row;
int column;
column = booksize.XProperties.IndexOf(front.CustomProps[booksize.XLabel])+1;
row = booksize.YProperties.IndexOf(front.CustomProps[booksize.YLabel])+1;
Frame newFrame = new Frame();
TaskBoardGrid.Children.Add(newFrame);
Grid.SetColumn(newFrame, column);
Grid.SetRow(newFrame, row);
}
The reason you cannot access your BooksGrid is because it will be dynamically generated for each book in the books collection. So for every book a Grid will be generated.
OPTION 1:
You can add a Loaded event to your grid:
<Pivot x:Name="Pivot" ItemsSource="{x:Bind books}">
<Pivot.HeaderTemplate>
<DataTemplate x:DataType="local:Book">
<TextBlock Text="{x:Bind Name}"/>
</DataTemplate>
</Pivot.HeaderTemplate>
<Pivot.ItemTemplate>
<DataTemplate>
<Grid
BorderBrush="Black" BorderThickness="1,1,0,0"
Margin="0,10,0,0" Loaded="DrawGrid">
</Grid>
</DataTemplate>
</Pivot.ItemTemplate>
and in your code behind:
private void DrawGrid(object sender, RoutedEventArgs e)
{
Grid grid = sender as Grid;
// Load your grid..
}
EDIT - OPTION 2:
If you'd like to access your grids from code behind in a different way (like suggested in your edit) you can always do the following:
private void DrawBooksFront(Front front)
{
// Loop through the pivot's items and get the content from each item's ContentTemplate.
foreach (var item in Pivot.Items)
{
PivotItem pivotItem = Pivot.ContainerFromItem(item) as PivotItem;
Grid grid = pivotItem.ContentTemplate.LoadContent() as Grid;
// Do something with the grid.
}
}
If your goal is to display previews of the pages of the book inside a PivotItem in a grid-like manner [picture below], then you're better off placing GridView in a DataTemplate of Pivot.ItemTemplate and using data binding to display those pages automatically, this would eliminate the need to write the code in xaml.cs that you showed.
Please, share more details about your app (what you're given and what the end result should look like) so we could help you better.

WPF - Elements inside DataTemplate property issue when no binding?

I have the following TabControl:
<TabControl ItemsSource="{Binding Tabs"}>
<TabControl.ContentTemplate>
<DataTemplate DataType="{x:Type vm:TabVM}">
<TextBox></TextBox>
<TextBox Text="{Binding SomeProperty}"></TextBox>
</DataTemplate>
</TabControl.ContentTemplate>
</TabControl>
The unexpected behaviour is that first TextBox has Text property shared between all tabitems, while second TextBox effectively bind to ViewModel property.
My need is to make independent the first TextBox too, even without binding.
What can I do ?
** UPDATE **
After several tries I've decided to use the ikriv's TabContent.cs.
The only issue I've found with this is that calling the TabControl.Items.Refresh() (i.e. after removing a tabItem) cause the reset of the internal cache.
An unelegant but effective solution may be this:
public ContentManager(TabControl tabControl, Decorator border)
{
_tabControl = tabControl;
_border = border;
_tabControl.SelectionChanged += (sender, args) => { UpdateSelectedTab(); };
/* CUSTOM */
var view = CollectionViewSource.GetDefaultView(((TabControl)_tabControl).Items);
view.CollectionChanged += View_CollectionChanged;
}
/*
* This fix the internal cache content when calling items->Refresh() method
* */
private void View_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
if (e.OldItems != null)
{
/* Retrieve all tabitems cache and store to a temp list */
IList<ContentControl> cachedContents = new List<ContentControl>();
foreach (var item in _tabControl.Items)
{
var tabItem = _tabControl.ItemContainerGenerator.ContainerFromItem(item);
var cachedContent = TabContent.GetInternalCachedContent(tabItem);
cachedContents.Add(cachedContent);
}
/* rebuild the view */
_tabControl.Items.Refresh();
/* Retrieve all cached content and store to the tabitems */
int idx = 0;
foreach (var item in _tabControl.Items)
{
var tabItem = _tabControl.ItemContainerGenerator.ContainerFromItem(item);
TabContent.SetInternalCachedContent(tabItem, cachedContents[idx++]);
}
}
}
You should use data binding since the same ContentTemplate will be applied for all items in your ItemsSource. Only the binding will be refreshed when you switch tabs basically. The TextBox isn't re-created nor reset.
What can I do ?
You could work around this in the view by handling the SelectionChanged event of the TabControl and reset the TextBox control yourself:
private void tabs_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
TabControl tc = sender as TabControl;
ContentPresenter cp = tc.Template.FindName("PART_SelectedContentHost", tc) as ContentPresenter;
if(cp != null && VisualTreeHelper.GetChildrenCount(cp) > 0)
{
ContentPresenter cpp = VisualTreeHelper.GetChild(cp, 0) as ContentPresenter;
if(cpp != null)
{
TextBox textBox = cpp.FindName("txt") as TextBox;
if (textBox != null)
textBox.Text = string.Empty;
}
}
}
<TabControl x:Name="tabs" ItemsSource="{Binding Tabs}" SelectionChanged="tabs_SelectionChanged">
<TabControl.ContentTemplate>
<DataTemplate>
<ContentPresenter>
<ContentPresenter.Content>
<StackPanel>
<TextBox x:Name="txt"></TextBox>
</StackPanel>
</ContentPresenter.Content>
</ContentPresenter>
</DataTemplate>
</TabControl.ContentTemplate>
</TabControl>
If you want to persist the text in the TextBox when you switch tabs you could use the attached behaviour from the following article and set its IsCached property to true: https://www.codeproject.com/articles/460989/wpf-tabcontrol-turning-off-tab-virtualization
<TabControl ItemsSource="{Binding Items}" behaviors:TabContent.IsCached="True">
<!-- Make sure that you don't set the TabControl's ContentTemplate property but the custom one here-->
<behaviors:TabContent.Template>
<DataTemplate>
<StackPanel>
<TextBox />
</StackPanel>
</DataTemplate>
</behaviors:TabContent.Template>
</TabControl>
Yet another approach would be to modify the ControlTemplate of the TabControl to include a ListBox as suggested by 'gekka' in the following thread on the MSDN forums: https://social.msdn.microsoft.com/Forums/en-US/4b71a43a-26f5-4fef-8dc5-55409262298e/using-uielements-on-datatemplate?forum=wpf

Nesting a Label inside a ListView in XAML

I am pretty new to WPF and I have tried figuring out how to add a Label appear inside a the following ListView which shows the number of Items currently in the ListView. I've given the ListView padding on the top to make room for the Label.
<ListView x:Name="MyListView" Grid.Row="0" Grid.Column="0" Margin="0,40,0,0" Padding="0" HorizontalAlignment="Stretch"
VerticalAlignment="Stretch" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch">
<ListView.ItemTemplate>
<DataTemplate>
<WrapPanel>
<TextBlock Text="{Binding DatasetCode}" FontWeight="Bold"/>
</WrapPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
If anyone can help me out, it would be greatly appreciated.
Edit the Template of ListBox. You can do this by Right-Clicking the ListBox in the Document outline section. And add your Label as below.
...
<ScrollViewer Focusable="false" Padding="{TemplateBinding Padding}">
<StackPanel>
<Label uc:Window2.CountFor="False" />
<ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</StackPanel>
</ScrollViewer>
...
I have written an attached property CountFor . Code is give below :
#region CountFor attached property
public static bool GetCountFor(DependencyObject obj)
{
return (bool)obj.GetValue(CountForProperty);
}
public static void SetCountFor(DependencyObject obj, bool value)
{
obj.SetValue(CountForProperty, value);
}
// Using a DependencyProperty as the backing store for CountFor. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CountForProperty =
DependencyProperty.RegisterAttached("CountFor", typeof(bool), typeof(Window2), new PropertyMetadata(false, new PropertyChangedCallback(GetCountForChanged)));
private static void GetCountForChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if ((bool)e.NewValue == false) return;
Label lbl = (Label)d;
lbl.Loaded += (o, args) =>
{
DependencyObject parent = VisualTreeHelper.GetParent(lbl);
while (parent.GetType() != typeof(ListBox))
parent = VisualTreeHelper.GetParent(parent);
ListBox lb = (ListBox)parent;
ICollectionView view = CollectionViewSource.GetDefaultView(lb.ItemsSource);
lbl.Content = "Number of items = " + ((ListCollectionView)view).Count;
view.CollectionChanged += (col, colargs) =>
{
lbl.Content = "Number of items = " + ((ListCollectionView)col).Count;
System.Diagnostics.Debug.WriteLine(((ListCollectionView)col).Count.ToString());
};
};
}
#endregion
Your solution is simple, you could just create an int to count the number of items in your label and then assign a new textblock, you could also completely skip the textblock and simply add the int, check this code:
private void button1_Click(object sender, RoutedEventArgs e)
{
int testcounter;
testcounter = listBox.Items.Count;
TextBlock BlockCounter = new TextBlock();
BlockCounter.Text = testcounter.ToString();
listBox.Items.Add(BlockCounter);
}

Data binding in Windows Phone 8 app using ListBox

Here is my code. What it doing. I have one textbox(button) with text Book name, when I click on it I can change text in textbox using binding. But now I add another textbox for author name and I dont know how bind it. If I use same method like for Book name its not works or text from book name is too in book author. All text are changed via popup setting page.
My source here: https://dl.dropbox.com/u/40039421/App1.rar.
Image here: https://dl.dropbox.com/u/40039421/helpp.png
public partial class MainPage : INotifyPropertyChanged
{
private ObservableCollection<Book> _books = new ObservableCollection<Book>();
public ObservableCollection<Book> AllBooks
{
get { return _books; }
set { _books = value; }
}
...
private void InitializeData()
{
var bookName1 = new Book { Id = 1, BookName = "Small red apple",AuthorName = "Daniel"};
...
AllBooks.Add(bookName1);
...
OnPropertyChanged("AllBooks");
}
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(null, new PropertyChangedEventArgs(propertyName));
}
}
private void btnGreenBook_Click(object sender, RoutedEventArgs e)
{
var button = sender as Button;
if (button != null)
{
Popup popup = new Popup();
popup.VerticalOffset = 30;
PopupSettingPage control = new PopupSettingPage();
popup.Child = control;
popup.IsOpen = true;
control.btnSave.Click += (s, args) =>
{
var id = Convert.ToInt32(button.Tag);
var book = AllBooks.FirstOrDefault(sub => sub.Id == id);
if (book != null)
{
book.BookName = control.BookName;
book.OnPropertyChanged("BookName");
}
popup.IsOpen = false;
};
...
Ohh dear, it was a simple mistake :)
You forgot to add the AuthorName in the Xaml of your PopupSettingsPage.xaml
<TextBox x:Name="tbInputAuthorName" Text="{Binding AuthorName, Mode=TwoWay}" VerticalAlignment="Center"/>
And then in MainPage do this
book.BookName = control.BookName;
book.OnPropertyChanged("BookName");
book.AuthorName = control.AuthorName;
book.OnPropertyChanged("AuthorName");
Additional answer based on your comments:
In order to achieve that, You have to remove the second stackpanel in the listbox. Instead, use the WrapPanel control. Search for how to use WrapPanel for WindowsPhone.
And then you have to find some way to set the backgrounds as red or green. Good luck
OK I use wrap panel but problem is still here. I have two panorama items (I post code from item 1 and item 2 have same code only is showing on second panorama page) and problem is still if I save some value to one of item in panorama item 1 this value is too in panorama item 2 and I dont know how make it. Logic is click on panorama 1 item change values in panoam 1 items, click on panorama 2 items change panorama 2 items values. Its look like panoram item 1 have same ID like panoram item 2. Here is full source : https://dl.dropbox.com/u/40039421/App1SecondEdit.rar
<Grid x:Name="LayoutRoot" Background="Transparent">
<!--Panorama control-->
<phone:Panorama>
<!--Panorama item 1-->
<phone:PanoramaItem Header="Test">
<Grid x:Name="PanelPanoramaItem1"
Grid.Row="1"
Margin="25,0,12,0">
<ListBox ItemsSource="{Binding AllBooks}">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<toolkit:WrapPanel Orientation="Vertical"/>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<Button Width="140"
Height="140"
toolkit:TiltEffect.IsTiltEnabled="True" Margin="0,0,0,5" Click="Button_Click_1" Tag="{Binding Id}" >
<Button.Template>
<ControlTemplate>
<Grid Background="Chartreuse">
<TextBlock Foreground="Black" Text="{Binding BookName}" />
</Grid>
</ControlTemplate>
</Button.Template>
</Button>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</phone:PanoramaItem>
<!-- END Panorama item 1 -->

Categories

Resources