WPF: How to capture selected text in a textbox embedded in ListView - wpf

Question

I am trying to get a selected text in a TextBox embedded in a listView. This seems so easy, but I couldn't really find a elegant solution.
When I click on "Create Rule" menu item, I want to get the TextBox in which the menu item resides.
I appreciate any help! I spent way too long of my time on this...
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I want to get the text in the code behind like this...
private void CreateRuleMenuItem_Click(object sender, RoutedEventArgs e)
{
TextBox txtBox = // ???
string selectedText = txtBox.selectedText;

Answer 1

Thank you very much for your propmt help! It is a template control as shown below.
<GridViewColumn Header="Content">
<GridViewColumn.CellTemplate>
<DataTemplate>
<TextBox Text="{Binding Path=record_content}" Width="800">
<TextBox.ContextMenu>
<ContextMenu>
<MenuItem Name="CreateRuleMenuItem"
Header="Create Rule"
Click="CreateRuleMenuItem_Click"/>
<MenuItem Name="DeleteRuleMenuItme"
Header="Delete Rule"
Click="DeleteRuleMenuItme_Click"/>
</ContextMenu>
</TextBox.ContextMenu>
</TextBox>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>

Answer 2

Is this a templated control? If not, you should be able to add a name tag, x:Name="txtTextbox" and then just address it directly, txtTextBox.SelectedText.
Since this is a templated control you don't have direct access via name.
So in your code-behind you could use a method like the following which will find the first Parent of the element specified of a particular type (TextBox). Place the following method into a helper class, or within your existing code:
/// <summary>
/// Finds a parent of a given item on the visual tree.
/// </summary>
/// <typeparam name="T">The type of the queried item.</typeparam>
/// <param name="child">A direct or indirect child of the
/// queried item.</param>
/// <returns>The first parent item that matches the submitted
/// type parameter. If not matching item can be found, a null
/// reference is being returned.</returns>
public static T TryFindParent<T>(this DependencyObject child)
where T : DependencyObject
{
//get parent item
DependencyObject parentObject = GetParentObject(child);
//we've reached the end of the tree
if (parentObject == null) return null;
//check if the parent matches the type we're looking for
T parent = parentObject as T;
if (parent != null)
{
return parent;
}
else
{
//use recursion to proceed with next level
return TryFindParent<T>(parentObject);
}
}
Then you just do this code in your code event handler:
MenuItem menuItem = sender as MenuItem;
if(menuItem!=null)
{
TextBox textBox = menuItem.TryFindParent<TextBox>();
if(textBox!=null)
{
string selectedText = textBox.SelectedText;
}
}
This method is helpful in many of my projects, so I create a UIHelper class that I put these types of things into...
Good Luck,
Jason

Answer 3

I would clearly recommand you using MVVM and databinding in this case.
I see you have a class XXX with a "record_content" property which is bound to the Text Property of the TextBox. (I think that you omitted the Mode=TwoWay Binding option to ensure that changes in the TextBox change the record_content property value)
You could add a recordContentSelectedText property, bound to the SelectedText property of your TextBox:
<TextBox [...] SelectedText="{Binding recordContentSelectedText,Mode=TwoWay}"/>
the datacontext of your TextBox is an instance of XXX which record_content contains the TextBox content.... And the ContextMenu and its items have the same DataContext!
If the property value is correctly updated by your databinding, it will be very easy:
var data = this.DataContext as XXX;
var selectedText = this.recordContentSelectedText;
It will work only if your DataContext is bound only to one TextBox in the list. Otherwise, TextBox selected text synchronization will occur as a side effect (I don't know if you understand what I mean, but it could be an issue or not, depending on the behavior you expect from your app)