I have a WPF window with 4 read-only TextBoxes in it, to all of which I need to enable a context menu with copy option. Currently I'm doing with code behind. But I heard it is not a good approach.
<TextBox Name="StepsTextBox"
Text="{Binding Steps, Mode=OneWay}"
IsReadOnly="True"
Click="Copy_click"/>
Code-Behind:
private void Copy_click(object sender, RoutedEventArgs e)
{
StepsTextBox.Copy();
}
I tried using MVVM as follows:
<TextBox.ContextMenu>
<ContextMenu>
<MenuItem Header="Copy" Command="{Binding OnCopyButtonClick}" CommandParameter="{Binding ElementName=StepsTextBox}"/>
</ContextMenu>
</TextBox.ContextMenu>
But how do I access this text box from the code if I pass it as parameter. And also how can I keep this code generic for all the textboxes?. Could anyone help?. Thanks in advance.
private void OnCopyButtonClick(TextBox textBox)
{
//??
}
You can use the build-in ApplicationCommands.Copy. No need to implement anything, the copy functionality is already implemented.
<TextBox.ContextMenu>
<ContextMenu>
<MenuItem Header="Copy" Command="Copy" />
</ContextMenu>
</TextBox.ContextMenu>
You will still have to select the text before copying it, but that's to be expected when copying text.
Related
There is an application I want to make using C#. This is part of it's UI:
The white area below the menu bar represents a TreeView. I want the Tree_View menu to appear everywhere in the white area when right-clicking with the mouse.
This is the XAML code for the Tree_View object (mind the foo function there):
<MenuItem Name="Menu_Tree" Header="_Tree_View">
<MenuItem Header="_New_Scene" IsCheckable="false" Click = foo/>
<MenuItem Header="_Copy_This_Scene" IsCheckable="false"/>
<MenuItem Header="_Remove_This_Scene" IsCheckable="false"/>
<Separator />
<MenuItem Header="_New_Shot" IsCheckable="false"/>
<MenuItem Header="_Copy_This_Shot" IsCheckable="false"/>
<MenuItem Header="_Remove_This_Shot" IsCheckable="false"/>
<Separator />
<MenuItem Header="_Move_This_Shot_Up" IsCheckable="false"/>
<MenuItem Header="_Move_This_Shot_Down" IsCheckable="false"/>
</MenuItem>
and this is the XAML code for the Tree_View object:
<Grid Name="TreeHolder" Column="0" Margin="20,10,10,10" Background="DimGray">
<TreeView Name="myTree" MouseRightButtonDown="something" ToolTip="Right Click to Add or Remove Scenes and Scots.">
</TreeView>
</Grid>
This is the something function which should be triggered by right-click:
private void something(object sender, MouseButtonEventArgs e)
{
ContextMenu cm = new ContextMenu();
//cm.Items.Add("Add a New Scene ?", ... );
Menu_Tree.ContextMenu = cm;
}
Since nothing works there, I want to ask the following:
a) How to make the Tree_view menu items appear in the Tree_View object white area as well?
b) If so, how will I make it an enabled menu, for example being able to trigger the foo function?
(In other worlds, make an exact copy of the menu list, make it visible with right click and make it work as well)
I strongly believe that it has to do with the ContextMenu which I am not able to use fairly, so any help would be highly appreciated.
The items to add are MenuItems. You can create each item as you would with any other object, set its Header property and assign a Click event handler. The sender is the TreeView itself.
private void something(object sender, MouseButtonEventArgs e)
{
var cm = new ContextMenu();
var newSceneMenuItem = new MenuItem { Header = "_New_Scene" };
newSceneMenuItem.Click += OnNewSceneClick;
cm.Items.Add(newSceneMenuItem);
var treeView = (TreeView) sender;
treeView.ContextMenu = cm;
}
private void OnNewSceneClick(object sender, RoutedEventArgs e)
{
MessageBox.Show("I am a Message Box.", "New Scene clicked");
}
However, you can do this much easier in XAML without the right click handler.
<Grid Name="TreeHolder" Column="0" Margin="20,10,10,10" Background="DimGray">
<TreeView Name="myTree" ToolTip="Right Click to Add or Remove Scenes and Scots.">
<TreeView.ContextMenu>
<ContextMenu>
<MenuItem Header="_New_Scene" Click="foo"/>
<MenuItem Header="_Copy_This_Scene"/>
<MenuItem Header="_Remove_This_Scene"/>
<Separator />
<MenuItem Header="_New_Shot"/>
<MenuItem Header="_Copy_This_Shot"/>
<MenuItem Header="_Remove_This_Shot"/>
<Separator />
<MenuItem Header="_Move_This_Shot_Up"/>
<MenuItem Header="_Move_This_Shot_Down"/>
</ContextMenu>
</TreeView.ContextMenu>
</TreeView>
</Grid>
You do not need to set the IsCheckable to false, that is already the default value. Instead of assigning a Click event handler you could use commands, but I guess this would be a too advanced topic for you question, since it does not look like you are employing the MVVM pattern.
In WPF I can define a Command for copying content like this:
<MenuItem Header="Copy" Command="ApplicationCommands.Copy" >
Works great and the menu item is only enabled if there is something to copy.
I want to make another MenuItem that is also only enabled if there is something to copy in my app. How can I copy that behavior?
If I'm reading your question correctly, then the two menu items have the same criteria for if they are enabled. If that is the case, I think you could just bind your second menu item's IsEnabled property to the first menu item's IsEnabled property.
(Just confirmed that this works for me).
As an example:
<MenuItem x:Name="CopyItem" Header="Copy" Command="ApplicationCommands.Copy"/>
<MenuItem Header="Something Else" IsEnabled="{Binding ElementName=CopyItem, Path=IsEnabled}"/>
You can use the same command "Copy", and distinguish between two different menu items by CommandParameter:
<MenuItem Header="Copy" Command="ApplicationCommands.Copy" CommandParameter="PlainCopy">
<MenuItem Header="TrickyCopy" Command="ApplicationCommands.Copy" CommandParameter="TrickyCopy">
Then in Command handler check parameter:
private void OnCopy(object sender, ExecutedRoutedEventArgs e)
{
if (e.Parameter == 'PlainCopy')
{
...
}
else
{
...
}
}
I have something like below. For MenuItem, here I am passing an object of that MenuItem as a CommandParameter. This works fine for me. My MenuItem holds a RadioButton and I want to use the MenuItem CommandParameter value for this RadioButton. Could anyone please help me how to do this. Thanks in Advance.
<MenuItem Header="Name"
VerticalAlignment="Center"
VerticalContentAlignment="Center"
Command="{Binding SortCommand}"
CommandParameter="{Binding RelativeSource={RelativeSource Self}}">
<MenuItem.Icon>
<RadioButton VerticalAlignment="Center"
Margin="3"
IsChecked="True"
GroupName="sort"
Command="{Binding SortCommand}"
CommandParameter="..." />
</MenuItem.Icon>
</MenuItem>
Now Command is executing only when I select the MenuItem. I want to do the same when user selects the RadioButton also. Below is the code which I am using for this.
public void OnSortCommandExecuted(object menuItem)
{
MenuItem menu = menuItem as MenuItem;
if (menu != null)
{
((RadioButton)menu.Icon).IsChecked = !((RadioButton)menu.Icon).IsChecked;
this.eAggregator.GetEvent<ImagesSortedEvent>().Publish(menu.Header.ToString());
}
}
Like I said in the comments as well, it's not a good practise to pass on UI component as CommandParameter to ViewModel since ViewModel shouldn't know about View.
I would suggest you to have proper binding in ViewModel. Create a bool property in ViewModel and bind with IsChecked DP of radioButton. That ways you don't have to pass any CommandParameter from View, simply check the status of bool property from command execute method.
Now, that why MenuItem can't be accessed from RadioButton?
RadioButton doesn't lie in same Visual tree as that of MenuItem.
So, you can't use RelativeSource to travel upto MenuItem. Also ElementName binding won't work here since this to work both elements should lie in same Visual Tree.
You might find over net to use x:Reference in such cases where two elements doesn't lie in same Visual tree but that won't work here since it will create cyclic dependency.
Last thing, you have to resort with it to use Freezable class object to hold an instance of MenuItem and use that resource in your bindings.
First of all you need to define class deriving from Freezable:
public class BindingProxy : Freezable
{
#region Overrides of Freezable
protected override Freezable CreateInstanceCore()
{
return new BindingProxy();
}
#endregion
public object Data
{
get { return (object)GetValue(DataProperty); }
set { SetValue(DataProperty, value); }
}
public static readonly DependencyProperty DataProperty =
DependencyProperty.Register("Data", typeof(object),
typeof(BindingProxy));
}
and you can use it from XAML like this to pass MenuItem:
<MenuItem Header="Name"
x:Name="menuItem"
VerticalAlignment="Center"
VerticalContentAlignment="Center"
Command="{Binding SortCommand}"
CommandParameter="{Binding RelativeSource={RelativeSource Self}}">
<MenuItem.Resources>
<local:BindingProxy x:Key="proxy"
Data="{Binding Source={x:Reference menuItem}}"/>
</MenuItem.Resources>
<MenuItem.Icon>
<RadioButton VerticalAlignment="Center"
Margin="3"
IsChecked="True"
GroupName="sort"
Command="{Binding SortCommand}"
CommandParameter="{Binding Data.CommandParameter,
Source={StaticResource proxy}}"/>
</MenuItem.Icon>
</MenuItem>
Ofcourse you need to declare local namespace in XAML.
PS - I would still insist to use first approach to define proper bindings in ViewModel.
UPDATE
If MenuItem is placed under ContextMenu, then RelativeSource binding won't be possible. Approach described above will work in that case.
But in case you are placing MenuItem directly as child of some control (like Menu), RelativeSource binding will work:
CommandParameter="{Binding CommandParameter,
RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=MenuItem}}"
I have a context menu attached to a button on a toolbar on one of my controls in WPF (.NET 4.0). The context menu has a style assigned to it in the XAML that defines the context menu. Left clicking on the button opens the button's context menu if it isn't opened already.
Here's the relevant XAML:
<Button x:Name="fileButton" Foreground="White" Margin="7, 0, -3, 0" VerticalAlignment="Stretch" MaxHeight="70" MaxWidth="78" MinHeight="55" MinWidth="62" Style="{DynamicResource ImageButton}" utils:WpfImageUtil.Image="{StaticResource fileButton}" Template="{DynamicResource GlassButton}" Content="File" Visibility="Visible" Click="fileButton_Click">
<Button.ContextMenu>
<ContextMenu Style="{DynamicResource ContextMenuStyle}">
<MenuItem x:Name="saveMenuItem" Header="Save" Click="saveMenuItem_Click" Style="{DynamicResource MenuItemStyle}" />
<MenuItem x:Name="saveDrawingMenuItem" Header="Save Drawing" Click="saveMenuItem_Click" Style="{DynamicResource MenuItemStyle}" />
<MenuItem x:Name="openMenuItem" Header="Open" Style="{DynamicResource MenuItemStyle}">
<MenuItem x:Name="openFromFile" Header="From File" Style="{DynamicResource MenuItemStyle}" />
<MenuItem x:Name="openFromDesktop" Header="From Desktop" Style="{DynamicResource MenuItemStyle}" />
</MenuItem>
<MenuItem x:Name="iconsMenuItem" Header="Icons" ItemsSource="{Binding}" Style="{DynamicResource MenuItemStyle}"/>
<MenuItem x:Name="prefsMenuItem" Header="Preferences" Style="{DynamicResource MenuItemStyle}"/>
</ContextMenu>
</Button.ContextMenu>
</Button>
ContextMenuStyle is defined in a resource dictionary that is properly referenced.
When the context menu is opened with a left click, the style I have defined isn't applied to the menu, as shown below:
However, if the user right-clicks and opens the context menu the traditional way, the style is applied as expected:
Afterwards, left-clicking the button will show the style correctly:
I have been trying to figure this out for some time, but haven't been able to come up with any reason that this issue occurs. It seems like some kind of bug to me, but I'm not entirely sure. I also don't know what happens at the lower level when controls are right-clicked on that would cause the style to get applied correctly.
You should assign ContextMenu Style property in code (FindResource method msdn):
private void fileButton_Click(object sender, RoutedEventArgs e)
{
if (fileButton.ContextMenu.Style == null)
fileButton.ContextMenu.Style = this.FindResource("ContextMenuStyle") as Style;
fileButton.ContextMenu.IsOpen = true;
}
ContextMenu Overview (http://msdn.microsoft.com/en-US/library/ms742558.aspx)
A ContextMenu is attached to a specific control. The ContextMenu
element enables you to present users with a list of items that specify
commands or options that are associated with a particular control, for
example, a Button. Users right-click the control to make the menu
appear. ...
When you right-click on the control, style will be applied to the ContextMenu. So if you want to open ContextMenu in code, you should check if style is equal null and if it's true, you should assign appropriate style.
i'm a newbie in DOT NET
I'm building a WPF App using C# in which I have a MenuItem (Checkable) for toggling the Word Wrap feature on and of for a TextBox(Just like in Notepad) i.e to switch between TextWrapping="Wrap" and TextWrapping="NoWrap"
MenuItem :
<MenuItem Header="_Word Wrap" Name="wordWrap" IsCheckable="True" IsChecked="True" Checked="wrap_Click"/>
TextBox:
<TextBox TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Visible" Name="txtContent">
How to create a function so that , when the MenuItem is checked, it turns the Word wrap feature on and when the MenuItem is unchecked, it turns the Word wrap feature off
I tried the following piece of code ,
private void wrap_Click(object sender, RoutedEventArgs e)
{
if (wordWrap.IsChecked)
txtContent.TextWrapping = TextWrapping.Wrap;
else
txtContent.TextWrapping = TextWrapping.NoWrap;
}
but it shows an Exception at txtContent.TextWrapping = TextWrapping.Wrap; :
Object reference not set to an instance of an object.
Please help me
Thank you !
This doesn't seem to be a problem with your actual event. Just try changing your event to a click event.
So, change this:
<MenuItem Header="_Word Wrap" Name="wordWrap" IsCheckable="True" IsChecked="True" Checked="wrap_Click" />
To this:
<MenuItem Header="_Word Wrap" Name="wordWrap" IsCheckable="True" IsChecked="True" Click="wrap_Click" />
This solved the problem for me. You don't even have to change the event code. It is correct. For some reason, the compiler just didn't like having it as a checked event...