Character Casing in Silverlight 4 TextBox - silverlight-4.0

Question

I am writing a Silverlight 4 business application and have run into an issue. I need the text input in TextBoxes to be forced to UpperCase. What I understand from various forums is Silverlight does not Implement CharacterCasing and CSS Styling.
Is there any other way to achieve this?

Answer 1

You can achieve this by creating a behavior, like this:
public class UpperCaseAction : TriggerAction<TextBox>
{
protected override void Invoke(object parameter)
{
var selectionStart = AssociatedObject.SelectionStart;
var selectionLenght = AssociatedObject.SelectionLength;
AssociatedObject.Text = AssociatedObject.Text.ToUpper();
AssociatedObject.SelectionStart = selectionStart;
AssociatedObject.SelectionLength = selectionLenght;
}
}
Then, use it in your TextBox, like this:
<Grid x:Name="LayoutRoot" Background="White">
<TextBox TextWrapping="Wrap" VerticalAlignment="Top" Margin="10">
<i:Interaction.Triggers>
<i:EventTrigger EventName="TextChanged">
<ASD_Answer009_Behaviors:UpperCaseAction/>
</i:EventTrigger>
</i:Interaction.Triggers>
</TextBox>
</Grid>
Where i: is a namespace for
clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity
Code behind:
System.Windows.Interactivity.EventTrigger eventTrigger = new System.Windows.Interactivity.EventTrigger("TextChanged");
eventTrigger.Actions.Add(new UpperCaseAction());
System.Windows.Interactivity.Interaction.GetTriggers(myTextBox).Add(eventTrigger);
In order to create and use behaviors, you need to download and install the Expression Blend SDK for Silverlight 4 and add a reference to System.Windows.Interactivity.dll.

Answer 2

Try this:
private void txt2_KeyDown(object sender, KeyEventArgs e)
{
e.Handled = MakeUpperCase((TextBox)sender, e);
}
bool MakeUpperCase(TextBox txt, KeyEventArgs e)
{
if (Keyboard.Modifiers != ModifierKeys.None || (e.Key < Key.A) || (e.Key > Key.Z)) //do not handle ModifierKeys (work for shift key)
{
return false;
}
else
{
string n = new string(new char[] { (char)e.PlatformKeyCode });
int nSelStart = txt.SelectionStart;
txt.Text = txt.Text.Remove(nSelStart, txt.SelectionLength); //remove character from the start to end selection
txt.Text = txt.Text.Insert(nSelStart, n); //insert value n
txt.Select(nSelStart + 1, 0); //for cursortext
return true; //stop to write in txt2
}
}

Answer 3

private void txt2_KeyDown(object sender, KeyEventArgs e)
{
if (Keyboard.Modifiers != ModifierKeys.None) return; //do not handle ModifierKeys (work for shift key)
string n = new string(new char[] { (char)e.PlatformKeyCode });
int nSelStart = txt2.SelectionStart;
txt2.Text = txt2.Text.Remove(nSelStart, txt2.SelectionLength); //remove character from the start to end selection
txt2.Text = txt2.Text.Insert(nSelStart, n); //insert value n
txt2.Select(nSelStart + 1, 0); //for cursortext
e.Handled = true; //stop to write in txt2
}