WPF/バインディング - メモ帳ブログ @ wiki

バインディング

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例（エレメントのプロパティ同士）

<Slider Height="33" HorizontalAlignment="Center" Width="400"
    Minimum="10" Maximum="100" Interval="1" Name="fslider"/>
<TextBlock HorizontalAlignment="Center" Margin="0,20,0,0"
    FontSize="{Binding ElementName=fslider, Path=Value}">
    こんにちは
</TextBlock> 

プログラムの場合は以下．面倒なので必要がなければXAMLでやる．

// XAML
<Slider Height="33" HorizontalAlignment="Center" Width="400"
    Minimum="10" Maximum="100" Name="fslider"/>
<TextBlock HorizontalAlignment="Center" Margin="0,20,0,0" Name="ftext">
    こんにちは
</TextBlock> 

// C#
Binding b = new Binding();
b.Source = fslider;
b.Path = new PropertyPath("Value");
b.Mode = BindingMode.TwoWay;
ftext.SetBinding(TextBlock.FontSizeProperty, b); 

例（エレメントとオブジェクトのバインディング）

Valueというプロパティを持つNumber型をバインディングしてみる．
これがNumberクラス

using System;
using System.Collections.Generic;
using System.Text;
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.Shapes;
using System.ComponentModel;
 
namespace Test
{
    public class Number
        : INotifyPropertyChanged
    {
        public Number()
        {
            Value = 0;
        }
 
        public event PropertyChangedEventHandler PropertyChanged;
 
        private void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
 
        // Valueプロパティ	
        private Int32 _Value;
        public Int32 Value
        {
            get { return _Value; }
            set {
                _Value = value;
                NotifyPropertyChanged("Value");
            }
        }		
    }
} 

Int32をStringに変換するIValueConverter

using System;
using System.Collections.Generic;
using System.Text;
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.Shapes;
using System.Globalization;
 
namespace Test
{
    [ValueConversion(typeof(Int32), typeof(String))]
    public class NumberConverter
        : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return ((Int32) value).ToString();
        }
 
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
} 

そしてXAML．

<Window
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:sys="clr-namespace:System;assembly=mscorlib"
    xmlns:local="clr-namespace:Test"
    x:Class="Test.MainWindow"
    x:Name="Window"
    Title="MainWindow"
    Width="640" Height="480">
 
    <Window.Resources>
        <local:Number x:Key="number"/>
        <local:NumberConverter x:Key="nc"/>
    </Window.Resources>
 
    <StackPanel>
        <TextBlock HorizontalAlignment="Center" Margin="0,20,0,0" Text="{Binding Source={StaticResource number}, Path=Value, Converter={StaticResource nc}}"/>
        <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
            <Button Content="Add 10" Margin="10" Name="add"/>
            <Button Content="Subtract 10" Margin="10" Name="sub"/>
        </StackPanel>
    </StackPanel>
</Window> 

XAML.csはこんな感じ．

public partial class MainWindow : Window
{
    public MainWindow()
    {
        this.InitializeComponent();
 
        Number num = (Number) this.FindResource("number");
 
        this.add.Click += (e,s) => num.Value += 10;
        this.sub.Click += (e,s) => num.Value -= 10;
    }
} 

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カテゴリ：WPF