I knew how to make text disappear while writing: we should use GotFocus LostFocus. For the example I did it with this TextBox:

<TextBox x:Name="SearchNotes" Foreground="Gray" 
         Text="Search" LostFocus="NoteBox_OnLostFocus"
         GotFocus="NoteBox_GotFocus" BorderThickness="0" 
         Background="WhiteSmoke" TextChanged="TextBox_TextChanged" 
         Width="771"
         />

Here is the code:

public void NoteBox_GotFocus(object sender, RoutedEventArgs e)
{
    SearchNotes.Text = "";
    SearchNotes.Foreground = Brushes.White;
}

public void NoteBox_OnLostFocus(object sender, RoutedEventArgs e)
{
    SearchNotes.Text = "Search";
    SearchNotes.Foreground = Brushes.Gray;
}

Now, I am trying to do the same thing with another TextBox, but the problem is that the TextBoxis within a Window template so I don't have access to this TextBox from code (or I don't know how to access it)

This is XAML code:

<TextBox x:Name="WindowTextbox" GotFocus="WindowTextbox_GotFocus" LostFocus="WindowTextbox_LostFocus" Text="Type..." TextChanged="WindowTextbox_TextChanged" FontSize="15" Foreground="White" TextWrapping="Wrap" VerticalScrollBarVisibility="Auto" AcceptsReturn="True" Background="#404040" BorderThickness="0" Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3" Grid.RowSpan="3" Margin="0 0 0 23">
</TextBox>

When I am trying to access this from code I can't:

So I wanna know how to deal with this.

CodePudding user response：

That is what the sender parameter is for, see Routed Events Overview.

The object where the handler was invoked is the object reported by the sender parameter.

private void WindowTextbox_GotFocus(object sender, RoutedEventArgs e)
{
   var textBox = (TextBox)sender;
   textBox.Text = "";
   textBox.Foreground = Brushes.White;
}

private void WindowTextbox_LostFocus(object sender, RoutedEventArgs e)
{
   var textBox = (TextBox)sender;
   textBox.Text = "Search";
   textBox.Foreground = Brushes.Gray;
}

CodePudding user response：

Do you need the watermark of the textbox?
https://docs.microsoft.com/en-us/dotnet/desktop/wpf/controls/how-to-add-a-watermark-to-a-textbox?view=netframeworkdesktop-4.8
or
Create WPF Watermark in Pure XAML