How to create an object that derivative from TextBox ? - wpf

Question

I trying to create new class object that derivative from TextBox -
If there is chars in the TextBox - the new object will show some button and pressing on this button will be able to remove the chars in this TextBox
how can i make the derivative from control in WPF ?

Answer 1

You could create a new UserControl with a textbox and a button. You bind a string property to the textbox and to the visibility-property of your button. Then you create a converter which converts this string to a visibility. Now you bind the Command-property of your button to a command which sets the string property = string.Empty.
A few hints:
How to use Converters:
<UserControl.Resources>
<local:StringToVisibilityConverter x:Key="STV"></local:StringToVisibilityConverter>
</UserControl.Resources>
<Button Visibility="{Binding Path=MyText, Converter={StaticResource ResourceKey=STV}}" />
How your VM could look like:
public class MainViewModel:ViewModelBase
{
private string _mytext;
public string MyText
{
get
{
return _mytext;
}
set
{
_mytext = value;
OnPropertyChanged("MyText");
}
}
private RelayCommand<object> _clearTextCommand;
public ICommand ClearTextCommand
{
get
{
if (_clearTextCommand == null)
{
_clearTextCommand = new RelayCommand<object>(o => ClearText(), o => CanClearText());
}
return _clearTextCommand;
}
}
private void ClearText()
{
MyText = string.Empty;
}
private bool CanClearText()
{
return true;
}
}