ブログ

TextBoxにDoubleをバインドしておく。もしエンターキーを押されるとNaNにしてしまう細工を追加。

MainWindow.xaml

<window height="100" mc:ignorable="d" title="MainWindow" width="800" x:class="TextBoxAndDouble.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:local="clr-namespace:TextBoxAndDouble" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <grid>
        <viewbox>
            <textbox fontsize="34" keyup="TestKeyUp" text="{Binding Value, Mode=TwoWay, StringFormat=\{0:0.000\}, UpdateSourceTrigger=PropertyChanged, ValidatesOnNotifyDataErrors=False}" textalignment="Right" textwrapping="Wrap" width="800">
        </textbox></viewbox>
    </grid>
</window>

MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace TextBoxAndDouble
{
    /// <summary>
    /// MainWindow.xaml の相互作用ロジック
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            MainWindowsViewModel mainWindowsViewModel = new MainWindowsViewModel();
            this.DataContext = mainWindowsViewModel;
        }

        private void TestKeyUp(object sender, KeyEventArgs e)
        {
            TextBox textBox = (TextBox)sender;
            if (e.Key == Key.Return)
            {
                
                ((MainWindowsViewModel)this.DataContext).Value = Double.NaN;
            }
        }
    }
}

MainWindowsViewModel.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.ComponentModel;

namespace TextBoxAndDouble
{
    class MainWindowsViewModel : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        private void RaisePropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }

        private Double _value = 0.0;
        public Double Value
        {
            set
            {
                _value = value;
                RaisePropertyChanged("Value");
            }
            get
            {
                return _value;
            }

        }
    }
}