I am having an expander than bind in the listview.
And I have another button to collapse/ expand all expander.
In code behind, I couldn’t locate the expander by using the code: Expander exp = (Expander)listViewResult.FindResource("MyExpander");
Any idea to do so?
<ListView Name="listViewResult" Margin="0,172,-10,-491" BorderBrush="Gray" BorderThickness="1"
TextElement.FontFamily="Segoe UI" TextElement.FontSize="12"
Background="White"
GridViewColumnHeader.Click="GridViewColumnHeaderClickedHandler" >
<ListView.View>
<GridView ColumnHeaderContainerStyle="{StaticResource GridViewColumnHeaderStyle}" >
……
</GridView>
</ListView.View>
<ListView.GroupStyle>
<GroupStyle>
<GroupStyle.ContainerStyle>
<Style TargetType="{x:Type GroupItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<Expander Name="MyExpander" IsExpanded="False">
<Expander.Header>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Name}" FontWeight="Bold" VerticalAlignment="Bottom" />
</StackPanel>
</Expander.Header>
<ItemsPresenter Margin="20,0,0,0" />
<!--<ItemsPresenter />-->
</Expander>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupStyle.ContainerStyle>
</GroupStyle>
</ListView.GroupStyle>
</ListView>
In order to expand/ collapse all expander, you could locate all the expanders by finding all child in the collection
Calling the method:
Collection<Expander> collection = FindVisualChild<Expander>(listViewResult);
foreach (Expander expander in collection)
{
expander.IsExpanded = true;
}
The Method:
private static Collection<T> FindVisualChild<T>(DependencyObject current) where T : DependencyObject
{
if (current == null)
{
return null;
}
var children = new Collection<T>();
FindVisualChild (current, children);
return children;
}
private static void FindVisualChild<T>(DependencyObject current, Collection<T> children) where T : DependencyObject
{
if (current != null)
{
if (current.GetType() == typeof(T))
{ children.Add((T)current); }
for (int i = 0; i < System.Windows.Media.VisualTreeHelper.GetChildrenCount(current); i++)
{
FindVisualChild (System.Windows.Media.VisualTreeHelper.GetChild(current, i), children);
}
}
}
Use following method to find the controls within your Visual tree.
public static Visual GetDescendantByName (Visual element, string name)
{
if (element == null) return null;
if (element is FrameworkElement
&& (element as FrameworkElement).Name == name) return element;
Visual result = null;
if (element is FrameworkElement)
(element as FrameworkElement).ApplyTemplate();
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(element); i++)
{
Visual visual = VisualTreeHelper.GetChild(element, i) as Visual;
result = GetDescendantByName(visual, name);
if (result != null)
break;
}
return result;
}
where element will be your ListView and name will be name of the FrameworkElement you are looking for.
Try using x:Name property to define name for your expander and below code can help:
Expander exp = (Expander)listViewResult.FindName("MyExpander");
Related
I have the following WPF DataGrid with GroupStyle. I need to now which rows are expanded when I have expanded/collapsed event.
I add:
Expanded="Expander_Process" Collapsed="Expander_Process"
but in the event function Expander_Process when I try to get the row
var row = DataGridRow.GetRowContainingElement(expander);
if (row == null)
then the row is null. So my question is: how can I know which rows are expanded in the datagrid?
<DataGrid x:Name="gvOptionChain" AutoGenerateColumns="False" FontWeight="Bold" Background="#FF262626" Foreground="White" Width="1509"
ScrollViewer.CanContentScroll="True" ScrollViewer.VerticalScrollBarVisibility="Auto" ScrollViewer.HorizontalScrollBarVisibility="Auto"
Margin="53,120,89,4.333" HorizontalContentAlignment="Right" SelectionChanged="gvOptionChain_SelectionChanged" VirtualizingPanel.IsVirtualizingWhenGrouping="True"
VirtualizingPanel.IsVirtualizing="True" VirtualizingPanel.ScrollUnit ="Item" VirtualizingPanel.VirtualizationMode="Recycling" EnableRowVirtualization="True" EnableColumnVirtualization = "True"
HorizontalAlignment="Stretch" VerticalAlignment="Stretch" SelectionUnit="Cell" SelectedItem="{Binding SelectedItem, Mode=OneWay}" >
<GroupStyle>
<GroupStyle.ContainerStyle>
<Style TargetType="{x:Type GroupItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type GroupItem}">
<Expander IsExpanded="False" Foreground="#FFEEEEEE" Expanded="Expander_Process" Collapsed="Expander_Process" >
<Expander.Header>
<StackPanel Orientation="Horizontal">
<TextBlock FontWeight="Bold" Text="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type GroupItem}}, Converter={StaticResource ResourceKey=groupToTitleConverter}}" />
</StackPanel>
</Expander.Header>
<Expander.Content>
<ItemsPresenter />
</Expander.Content>
</Expander>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupStyle.ContainerStyle>
</GroupStyle>
private void Expander_Process(object sender, RoutedEventArgs e)
{
if (sender is Expander expander)
{
var row = DataGridRow.GetRowContainingElement(expander);
if (row == null)
{
}
}
}
on the expander event - get the rows that expanded throu
CollectionViewGroup Items1 = ((CollectionViewGroup)(expander.DataContext));
and update a flag about the IsExpanded status of the row . this event happens many times for each expand - so I add timer to process the rows only once
private System.Timers.Timer ExpandTimer;
private bool bIsTimerOn = false;
private void Expander_Process(object sender, RoutedEventArgs e)
{
if (sender is Expander expander)
{
CollectionViewGroup Items1 = ((CollectionViewGroup)(expander.DataContext));
for(int i = 0; i < Items1.Items.Count; i++)
{
OptScrtyData ScrtyData1 = (OptScrtyData)Items1.Items[i];
ScrtyData1.IsExpanded = expander.IsExpanded;
}
if (bIsTimerOn == false)
{
ExpandTimer.Start();
bIsTimerOn = true;
}
}
}
a better answer - activate the timer only if there is new expand status :
private void Expander_Process(object sender, RoutedEventArgs e)
{
if (sender is Expander expander)
{
CollectionViewGroup Items1 = ((CollectionViewGroup)(expander.DataContext));
bool bNewStatus = false;
for(int i = 0; i < Items1.Items.Count; i++)
{
OptScrtyData ScrtyData1 = (OptScrtyData)Items1.Items[i];
if (bNewStatus == false)
{
bNewStatus = ScrtyData1.IsExpanded != expander.IsExpanded;
}
ScrtyData1.IsExpanded = expander.IsExpanded;
}
if (bNewStatus == true)
{
ExpandTimer.Start();
}
}
}
In my program i create dynamically TabItems, and i can create a few the same items. Problem is when i am switching from one to second the same items. In this moment event:
private void TabCards_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (e.Source is TabControl)
{
...
}
}
run 2 times. I could give Stopwatch and block run this event twice time in a short period of time. But i dont think it is good solution.
Maybe have someone idea what can i do?
Edit
This is how i add item:
private void AddTabItemForCard(string cardName)
{
var style = (Style)resources.FindResource("Style" + cardName);
var tabItem = new TabItem
{
Style = style,
Header = cardName
};
TabCards.Items.Add(tabItem);
}
This is TabControl in xaml:
<TabControl x:Name="TabCards" Grid.Column="1" SelectionChanged="TabCards_SelectionChanged" >
</TabControl>
And style:
<Style x:Key="StyleWej" TargetType="{x:Type TabItem}">
<Setter Property="Background" Value="Transparent"/>
<Setter Property="AllowDrop" Value="True"/>
<EventSetter Event="PreviewMouseMove" Handler="TabItem_PreviewMouseMove"/>
<EventSetter Event="Drop" Handler="TabItem_Drop"/>
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<Grid>
<TextBlock TextWrapping="Wrap" Text="Adres(hex)" FontSize="15" Margin="10,10,396,444"/>
<ComboBox x:Name="AddressWej" HorizontalAlignment="Left" Margin="134,11,0,0" VerticalAlignment="Top" Width="120">
<ComboBoxItem>30</ComboBoxItem>
<ComboBoxItem>31</ComboBoxItem>
<ComboBoxItem>32</ComboBoxItem>
</ComboBox>
<TextBlock TextWrapping="Wrap" Text="Wejscie 1:" FontSize="15" Margin="10,126,396,337"/>
<TextBlock TextWrapping="Wrap" Text="Wejscie 2:" FontSize="15" Margin="10,156,396,307"/>
<TextBox TextWrapping="Wrap" Text="Wejscie1" Width="120" Margin="134,129,231,331"/>
<TextBox TextWrapping="Wrap" Text="Wejscie2" Width="120" Margin="134,157,231,302"/>
</Grid>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
Events:
private void TabItem_PreviewMouseMove(object sender, MouseEventArgs e)
{
if (!(e.Source is TabItem tabItem))
return;
if (Mouse.PrimaryDevice.LeftButton == MouseButtonState.Pressed)
{
DragDrop.DoDragDrop(tabItem, tabItem, DragDropEffects.All);
}
}
private void TabItem_Drop(object sender, DragEventArgs e)
{
var tabItemTarget = e.Source as TabItem;
var tabItemSource = e.Data.GetData(typeof(TabItem)) as TabItem;
if (!tabItemTarget.Equals(tabItemSource))
{
var tabControl = tabItemTarget.Parent as TabControl;
int sourceIndex = tabControl.Items.IndexOf(tabItemSource);
int targetIndex = tabControl.Items.IndexOf(tabItemTarget);
tabControl.Items.Remove(tabItemSource);
tabControl.Items.Insert(targetIndex, tabItemSource);
tabControl.Items.Remove(tabItemTarget);
tabControl.Items.Insert(sourceIndex, tabItemTarget);
}
}
And in TabCards_SelectionChanged i check with TabItem is it and run:
public static IEnumerable<T> FindVisualChildren<T>(DependencyObject rootObject) where T : DependencyObject
{
if (rootObject != null)
{
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(rootObject); i++)
{
DependencyObject child = VisualTreeHelper.GetChild(rootObject, i);
if (child != null && child is T)
yield return (T)child;
foreach (T childOfChild in FindVisualChildren<T>(child))
yield return childOfChild;
}
}
}
to find all TextBox from TabItem
enter image description here
I have a custom control `AutoCompleteTextBox in a DataTemplate as shown below:
<DataGridTextColumn.HeaderTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical">
<TextBlock
Text="{Binding Content, RelativeSource={RelativeSource Mode=TemplatedParent}}"
Margin="5" />
<Border DockPanel.Dock="Top"
HorizontalAlignment="Left"
VerticalAlignment="Center"
Padding="2">
<uc:AutoCompleteTextBox x:Name="AutoTextBox" />
</Border>
</StackPanel>
</DataTemplate>
</DataGridTextColumn.HeaderTemplate>
How can i Access AutoTextBox in code Behind?
It is not possible to access controls in a DataTemplate directly by name! But you could try getting down the VisualTree...
DependencyObject dgColumnHeader = GetYourColumnHeader();
var yourAutoCompleteTextBox = FindVisualChild<AutoCompleteTextBox>(dgColumnHeader);
public static T FindVisualChild<T>(DependencyObject parent) where T : DependencyObject
{
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
{
DependencyObject child = VisualTreeHelper.GetChild(parent, i);
if (child != null && child is T)
return (T)child;
else
{
T childOfChild = FindVisualChild<T>(child);
if (childOfChild != null)
return childOfChild;
}
}
return null;
}
I have a ListBox including an ItemTemplate with 2 StackPanels.
There is a TextBox in the second StackPanel i want to access.
(Change it's visibility to true and accept user input)
The trigger should be the SelectionChangedEvent. So, if a user clicks on an ListBoxItem, the TextBlock gets invisible and the TextBox gets visible.
XAML CODE:
<ListBox Grid.Row="1" Name="ContactListBox" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" ItemsSource="{Binding Contacts}" Margin="0,36,0,0" SelectionChanged="ContactListBox_SelectionChanged">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Margin="0,0,0,0">
<toolkit:ContextMenuService.ContextMenu>
<toolkit:ContextMenu>
<toolkit:MenuItem Header="Edit Contact" Click="ContactMenuItem_Click"/>
<toolkit:MenuItem Header="Delete Contact" Click="ContactMenuItem_Click"/>
</toolkit:ContextMenu>
</toolkit:ContextMenuService.ContextMenu>
<Grid>
<Rectangle Fill="{StaticResource PhoneAccentBrush}"
Width="72" Height="72">
<Rectangle.OpacityMask>
<ImageBrush ImageSource="/Images/defaultContactImage.png" Stretch="UniformToFill"/>
</Rectangle.OpacityMask>
</Rectangle>
</Grid>
<StackPanel>
<TextBox Text="{Binding Name}" TextWrapping="Wrap" Visibility="Collapsed"/>
<TextBlock Text="{Binding Name}" TextWrapping="Wrap" Style="{StaticResource PhoneTextExtraLargeStyle}" />
<TextBlock Text="{Binding Number}" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextAccentStyle}"/>
</StackPanel>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
I guess there are several ways to solve this, but nothing I tried worked.
My current approach looks like this
private void ContactListBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
ListBoxItem listBoxItem = ContactListBox.SelectedItem as ListBoxItem;
DataTemplate listBoxTemplate = listBoxItem.ContentTemplate;
// How to access the DataTemplate content?
StackPanel outerStackPanel = listBoxTemplate.XXX as StackPanel;
StackPanel innerStackPanel = outerStackPanel.Children[1] as StackPanel;
TextBox nameBox = innerStackPanel.Children[0] as TextBox;
TextBlock nameBlock = innerStackPanel.Children[1] as TextBlock;
nameBox.Visibility = System.Windows.Visibility.Visible;
nameBlock.Visibility = System.Windows.Visibility.Collapsed;
}
Thank you for your help guys!! Finally i got it. Solved the problem with the VisualTreeHelper. What a great function ^^
private void ContactListBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (ContactListBox.SelectedIndex == -1)
return;
currentSelectedListBoxItem = this.ContactListBox.ItemContainerGenerator.ContainerFromIndex(ContactListBox.SelectedIndex) as ListBoxItem;
if (currentSelectedListBoxItem == null)
return;
// Iterate whole listbox tree and search for this items
TextBox nameBox = helperClass.FindDescendant<TextBox>(currentSelectedListBoxItem);
TextBlock nameBlock = helperClass.FindDescendant<TextBlock>(currentSelectedListBoxItem);
helperFunction
public T FindDescendant<T>(DependencyObject obj) where T : DependencyObject
{
// Check if this object is the specified type
if (obj is T)
return obj as T;
// Check for children
int childrenCount = VisualTreeHelper.GetChildrenCount(obj);
if (childrenCount < 1)
return null;
// First check all the children
for (int i = 0; i < childrenCount; i++)
{
DependencyObject child = VisualTreeHelper.GetChild(obj, i);
if (child is T)
return child as T;
}
// Then check the childrens children
for (int i = 0; i < childrenCount; i++)
{
DependencyObject child = FindDescendant<T>(VisualTreeHelper.GetChild(obj, i));
if (child != null && child is T)
return child as T;
}
return null;
}
With this edited function you can also search for control by name (its converted from VB.NET):
public T FindDescendantByName<T>(DependencyObject obj, string objname) where T : DependencyObject
{
string controlneve = "";
Type tyype = obj.GetType();
if (tyype.GetProperty("Name") != null) {
PropertyInfo prop = tyype.GetProperty("Name");
controlneve = prop.GetValue((object)obj, null);
} else {
return null;
}
if (obj is T && objname.ToString().ToLower() == controlneve.ToString().ToLower()) {
return obj as T;
}
// Check for children
int childrenCount = VisualTreeHelper.GetChildrenCount(obj);
if (childrenCount < 1)
return null;
// First check all the children
for (int i = 0; i <= childrenCount - 1; i++) {
DependencyObject child = VisualTreeHelper.GetChild(obj, i);
if (child is T && objname.ToString().ToLower() == controlneve.ToString().ToLower()) {
return child as T;
}
}
// Then check the childrens children
for (int i = 0; i <= childrenCount - 1; i++) {
string checkobjname = objname;
DependencyObject child = FindDescendantByName<T>(VisualTreeHelper.GetChild(obj, i), objname);
if (child != null && child is T && objname.ToString().ToLower() == checkobjname.ToString().ToLower()) {
return child as T;
}
}
return null;
}
I can't give you a complete answer...
But I think you can use the VisualTreeHelper to iterate through the children of any control
http://blogs.msdn.com/b/kmahone/archive/2009/03/29/visualtreehelper.aspx
However, for the effect you are looking for, then I think using the SelectedItem Style might be a better solution - e.g. see this article - http://joshsmithonwpf.wordpress.com/2007/07/30/customizing-the-selected-item-in-a-listbox/
Use ItemContainerGenerator.
private void ContactListBox_SelectionChanged
(object sender, SelectionChangedEventArgs e)
{
if (e.AddedItems.Count == 1)
{
var container = (FrameworkElement)ContactListBox.ItemContainerGenerator.
ContainerFromItem(e.AddedItems[0]);
StackPanel sp = container.FindVisualChild<StackPanel>();
TextBox tbName = (TextBox) sp.FindName("tbName");
TextBlock lblName = (TextBlock)sp.FindName("lblName");
TextBlock lblNumber = (TextBlock)sp.FindName("lblNumber");
}
}
Since DataTemplate is a generic template that could be used many times in the code, there is no way to access it by name (x:Name="numberTextBox").
I solved similar problem to this by making a collection of Controls - while Listbox was populating I add Textbox control to the collection.
string text = myCollectionOfTextBoxes[listbox.SelectedIndex].Text;
Till I found a better soultion - Tag property. In your ListboxItem you bind Tag property to the name
Tag="{Binding Name}"
and the to access it
ListBoxItem listBoxItem = ContactListBox.SelectedItem as ListBoxItem;
string name = listBoxItem.Tag.ToString();
I have some problems finding the right TextBlock control inside a StackPanel.
My markup:
<ListBox Name="lstTimeline" ItemContainerStyle="{StaticResource TwItemStyle}"
MouseDoubleClick="lstTimeline_MouseDoubleClick">
<ListBox.ItemTemplate>
<DataTemplate>
<DockPanel MaxWidth="{Binding ElementName=lstTimeline, Path=ActualWidth}">
<Border Margin="10" DockPanel.Dock="Left" BorderBrush="White"
BorderThickness="1" Height="48" Width="48" HorizontalAlignment="Center">
<Image Source="{Binding ThumbNail, IsAsync=True}" Height="48" Width="48" />
</Border>
<StackPanel Name="stkPanel" Margin="10" DockPanel.Dock="Right">
<TextBlock Text="{Binding UserName}" FontWeight="Bold" FontSize="18" />
<TextBlock Text="{Binding Text}" Margin="0,4,0,0" FontSize="14"
Foreground="#c6de96" TextWrapping="WrapWithOverflow" />
<TextBlock Text="{Binding ApproximateTime}" FontSize="14"
FontFamily="Georgia" FontStyle="Italic" Foreground="#BBB" />
<TextBlock Text="{Binding ScreenName}" Name="lblScreenName" FontSize="14"
FontFamily="Georgia" FontStyle="Italic" Foreground="#BBB"
Loaded="lblScreenName_Loaded" />
</StackPanel>
</DockPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
My double click code:
private void lstTimeline_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
ListBoxItem lbi = (lstTimeline.SelectedItem as ListBoxItem);
StackPanel item = lbi.FindName("stkPanel") as StackPanel;
if (item != null)
MessageBox.Show("StackPanel null");
TextBlock textBox = item.FindName("lblScreenName") as TextBlock;
if (textBox != null)
MessageBox.Show("TextBlock null");
MessageBox.Show(textBox.Text);
}
But the StackPanel is null. How do find the right TextBlock in SelectedItem?
Thanks for your help.
ListBoxItem myListBoxItem = (ListBoxItem)(lstUniqueIds.ItemContainerGenerator.ContainerFromIndex(lstUniqueIds.SelectedIndex));
ContentPresenter myContentPresenter = FindVisualChild<ContentPresenter>(myListBoxItem);
DataTemplate myDataTemplate = myContentPresenter.ContentTemplate;
CheckBox target = (CheckBox)myDataTemplate.FindName("chkUniqueId", myContentPresenter);
if (target.IsChecked)
{
target.IsChecked = false;
}
else
{
target.IsChecked = true;
}
Function FindVisualChild can be found on the MSDN page FrameworkTemplate.FindName Method:
private childItem FindVisualChild<childItem>(DependencyObject obj)
where childItem : DependencyObject
{
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
{
DependencyObject child = VisualTreeHelper.GetChild(obj, i);
if (child != null && child is childItem)
return (childItem)child;
else
{
childItem childOfChild = FindVisualChild<childItem>(child);
if (childOfChild != null)
return childOfChild;
}
}
return null;
}
There's a specific function to use when you're looking for something whose name is defined in a template. Try it like this:
private void lstTimeline_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
ListBoxItem lbi = (lstTimeline.SelectedItem as ListBoxItem);
StackPanel item = Template.FindName("stkPanel",lbi) as StackPanel;
if (item != null)
MessageBox.Show("StackPanel null");
TextBlock textBox = Template.FindName("lblScreenName",item) as TextBlock;
if (textBox != null)
MessageBox.Show("TextBlock null");
MessageBox.Show(textBox.Text);
}
Linq to xml with a get and set model.
var item = ...
lstTimeline.SelectedIndex = -1;
lstTimeline.ItemsSource = item;