对于Button的Command的绑定可以通过实现ICommand接口来进行，但是Slider并没有Command属性。

另外如果要实现MVVM模式的话，需要将一些Method和Slider的Event进行绑定，如何进行呢？

（对于UIElement的一些Event进行绑定一定有一些通用的方法，目前还没有深入研究。）

 

首先，Slider Value的绑定是很简单的, 绑定Slider的Value属性即可。

（1）ViewModel

public class SliderViewModel : ViewModelBase    {        private string selectedValue;        public SliderViewModel()        {        }        public string SelectedValue        {            get            {                return this.selectedValue;            }            set            {                if (this.selectedValue != value)                {                    this.selectedValue = value;                    base.OnPropertyChanged("SelectedValue");                 }            }        }    }

(2) View, 设定 DataContext 为ViewModel， 绑定SelectValue到 Slider的Value 和TextBlock的Text属性上。

这样当拖动Slider时，Slider的值会传给SelectedValue, 然后SelectValue会传给TexBlock上。

x:Class="WpfApplication2.View.SliderView"             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"              xmlns:d="http://schemas.microsoft.com/expression/blend/2008"              xmlns:vm="clr-namespace:WpfApplication2.ViewModel"             mc:Ignorable="d"              d:DesignHeight="300" d:DesignWidth="300">    
             
          
         
             
              
          
     

效果如下：

如果不想显示double值，可以设定Slider的属性。

TickFrequency="1"                IsSnapToTickEnabled="True"                TickPlacement="None" />

其次， 当用鼠标或者键盘移动滑块结束的时候，需要进行一些处理。如果不用MVVM的方式的话，可以在Slider的Event里面增加处理。

用MVVM的话，就稍微麻烦一些。

（1）下载或者复制C:\Program Files (x86)\Microsoft SDKs\Expression\Blend\.NETFramework\v4.0\Libraries\System.Windows.Interactivity.dll

        在工程中Reference 这个dll，命名空间里面增加：using System.Windows.Interactivity

 （2）新写个SliderValueChangedBehavior 继承Behavior<Slider>

/// 
    /// Helps find the user-selected value of a slider only when the keyboard/mouse gesture has ended.    /// 
    public class SliderValueChangedBehavior : Behavior
     
          {        /// 
      
        /// Keys down.        /// 
        private int keysDown;        /// 
      
        /// Indicate whether to capture the value on latest key up.        /// 
        private bool applyKeyUpValue;        #region Dependency property Value        /// 
      
        /// DataBindable value.        /// 
        public double Value        {            get { return (double)GetValue(ValueProperty); }            set { SetValue(ValueProperty, value); }        }        public static readonly DependencyProperty ValueProperty = DependencyProperty.Register(            "Value",            typeof(double),            typeof(SliderValueChangedBehavior),            new PropertyMetadata(default(double), OnValuePropertyChanged));        #endregion        #region Dependency property Value        /// 
      
        /// DataBindable Command        /// 
        public ICommand Command        {            get { return (ICommand)GetValue(CommandProperty); }            set { SetValue(CommandProperty, value); }        }        public static readonly DependencyProperty CommandProperty = DependencyProperty.Register(            "Command",            typeof(ICommand),            typeof(SliderValueChangedBehavior),            new PropertyMetadata(null));        #endregion        /// 
      
        /// On behavior attached.        /// 
        protected override void OnAttached()        {            this.AssociatedObject.KeyUp += this.OnKeyUp;            this.AssociatedObject.KeyDown += this.OnKeyDown;            this.AssociatedObject.ValueChanged += this.OnValueChanged;            base.OnAttached();        }        /// 
      
        /// On behavior detaching.        /// 
        protected override void OnDetaching()        {            base.OnDetaching();            this.AssociatedObject.KeyUp -= this.OnKeyUp;            this.AssociatedObject.KeyDown -= this.OnKeyDown;            this.AssociatedObject.ValueChanged -= this.OnValueChanged;        }        /// 
      
        /// On Value dependency property change.        /// 
        private static void OnValuePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)        {            var me = (SliderValueChangedBehavior)d;            if (me.AssociatedObject != null)                me.Value = (double)e.NewValue;        }        /// 
      
        /// Occurs when the slider's value change.        /// 
        /// 
              /// 
              private void OnValueChanged(object sender, RoutedPropertyChangedEventArgs
      
        e)        {            if (Mouse.Captured != null)            {                this.AssociatedObject.LostMouseCapture += this.OnLostMouseCapture;            }            else if (this.keysDown != 0)            {                this.applyKeyUpValue = true;            }            else            {                this.ApplyValue();            }        }        private void OnLostMouseCapture(object sender, MouseEventArgs e)        {            this.AssociatedObject.LostMouseCapture -= this.OnLostMouseCapture;            this.ApplyValue();        }        private void OnKeyUp(object sender, KeyEventArgs e)        {            if (this.keysDown-- != 0)            {                this.ApplyValue();            }        }        private void OnKeyDown(object sender, KeyEventArgs e)        {            this.keysDown++;        }        /// 
       
        /// Applies the current value in the Value dependency property and raises the command.        /// 
        private void ApplyValue()        {            this.Value = this.AssociatedObject.Value;            if (this.Command != null)                this.Command.Execute(this.Value);        }    }
      
     

 （3） 在View中为Slider的行为添加Command

（4）在ViewModel中实现当Slider值个改变的时候进行一些处理。

public ICommand ValueChangedCommand        {            get            {                if (this.valueChangedCommmand == null)                {                    this.valueChangedCommmand = new RelayCommand(                        param => this.PopValue(),                        null);                }                return this.valueChangedCommmand;             }        }        private void PopValue()        {            MessageBox.Show(String.Format("Selected value is {0}", this.selectedValue));         }

最后，进行调试，发现ValueChangedCommand当每次Silder值变更的时候都会被执行。

那么如何实现最后一次值变更时，才执行Command呢？