Automatically capitalize first letter in TextBoxes - wpf

Question

I am creating a wpf application. I have to make all textbox first letter to capital, if a user entered in small then it should be formatted in capital on mouse out.I need the best way to do it, please someone help me.

Answer 1

The best way of doing it greatly depends on how you are doing your app, but #H.B.'s answer is probably the way to go.
For the sake of completeness, another way if doing it would be to use a converter like so:
<!-- Your_Window.xaml -->
<Window x:Class="..."
...
xmlns:cnv="clr-namespace:YourApp.Converters">
<Window.Resources>
<cnv.CapitalizeFirstLetterConverter x:Key="capFirst" />
</Window.Resources>
...
<TextBox Text="{Binding Path=SomeProperty, Converter={StaticResource capFirst}}" />
This assumes that your window's data context is set to an instance of a class that has a read/write property named SomeProperty of type string.
The converter itself would be something like this:
// CapitalizeFirstLetterConverter.cs
using System;
using System.Data;
using System.Globalization;
namespace YourApp.Converters {
[ValueConversion(typeof(string), typeof(string))]
public class CapitalizeFirstLetterConverter : IValueConverter {
public object Convert(object value, Type targetType, object parameter, CultureInfo culture) {
// this will be called after getting the value from your backing property
// and before displaying it in the textbox, so we just pass it as-is
return value;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) {
// this will be called after the textbox loses focus (in this case) and
// before its value is passed to the property setter, so we make our
// change here
if (value is string) {
var castValue = (string)value;
return char.ToUpper(castValue[0]) + castValue.Substring(1);
}
else {
return value;
}
}
}
}
You can learn more about converters here.

Answer 2

You could put a style into the Application.Resources to handle LostFocus on all TextBoxes, then you just need to change the Text property accordingly.
<!-- App.xaml - Application.Resources -->
<Style TargetType="{x:Type TextBox}">
<EventSetter Event="LostFocus" Handler="TextBox_LostFocus" />
</Style>
// App.xaml.cs - App
private void TextBox_LostFocus(object sender, RoutedEventArgs e)
{
var tb = (TextBox)sender;
if (tb.Text.Length > 0)
{
tb.Text = Char.ToUpper(tb.Text[0]) + tb.Text.Substring(1);
}
}

Answer 3

I'm a bit late to the game, but if anybody else needs it this dll capitalizes the first letter in realtime. For example, you don't need to mouse out.
http://www.mardymonkey.co.uk/blog/auto-capitalise-a-text-control-in-wpf/

Answer 4

Perhaps you can use a converter but not a converter like #ssarabando, because it is bugged.
Here's the code of the converter:
using System;
using System.Globalization;
using System.Windows.Data;
namespace SistemaContable.GUI.WPF.Converters
{
public class CapitalizeFirstLetter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (value != null)
{
string stringToTitleCase = culture.TextInfo.ToTitleCase(value.ToString());
return stringToTitleCase;
}
else
{
return null;
}
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
return value.ToString();
}
}
}
You need to reference it in a "ResourceDictionary" or in your "App.xaml":
<ResourceDictionary xmlns:converters="clr-namespace:SistemaContable.GUI.WPF.Converters">
<converters:CapitalizeFirstLetter x:Key="CapitalizeFirstLetter"/>
</ResourceDictionary>
And you can use it like this:
<TextBox x:Name="txtNombre" Text="{Binding Usuario.Nombre, Converter={StaticResource CapitalizeFirstLetter}, UpdateSourceTrigger=PropertyChanged}"/>