我正在研究一个MVVM应用程序，我希望有一个ProgressBar，当该属性发生变化时，它可以平滑地为其提供新的值。我已经使用c＃看到了这个问题的几个答案，但我更喜欢在模板中完成所有操作。我遇到的问题是正确设置和定位事件和故事板。这是我目前的情况：
进度条 -
风格 - （只是触发器）
<ControlTemplate.Triggers>
<EventTrigger RoutedEvent="RangeBase.ValueChanged">
<BeginStoryboard>
<Storyboard>
<DoubleAnimation
Storyboard.TargetName="???????"
Storyboard.TargetProperty="Value"
To="???????" Duration="0:0:5" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
我从这里获取了触发器代码：http://msdn.microsoft.com/en-us/library/system.windows.controls.progressbar(v=vs.110).aspx。
如何将TargetName设置为模板本身，以便它适用于使用此模板的所有控件？如何设置＆＃34; To＆＃34;传入的价值？似乎有一种方法可以抓住＆＃34; Binding＆＃34;值，但我有Value和Max都绑定在progressbar元素上。它怎么知道要用什么？
以下是整个参考模板：
<Style x:Key="ProgressStyle" TargetType="{x:Type ProgressBar}">
<Setter Property="OverridesDefaultStyle" Value="True" />
<Setter Property="SnapsToDevicePixels" Value="True" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ProgressBar}">
<Grid MinHeight="14" MinWidth="20">
<Border x:Name="BaseRectangle" Background="{StaticResource BaseColor}" CornerRadius="10,0,10,0"></Border>
<Border x:Name="GlassRectangle" CornerRadius="10,0,10,0" Background="{StaticResource GlassFX}" Panel.ZIndex="10"></Border>
<Border x:Name="animation" CornerRadius="10,0,10,0" Opacity=".7" Background="{Binding Path=Foreground, RelativeSource={RelativeSource TemplatedParent}}" HorizontalAlignment="Left"></Border>
<Border x:Name="PART_Indicator" CornerRadius="10,0,10,0" Background="{Binding Path=Foreground, RelativeSource={RelativeSource TemplatedParent}}" HorizontalAlignment="Left"></Border>
<Border x:Name="PART_Track" BorderThickness="1" CornerRadius="10,0,10,0" BorderBrush="Black"></Border>
<Border x:Name="BordeCabeceraSombra" BorderThickness="2" CornerRadius="10,0,10,0" BorderBrush="DarkGray" Opacity=".2" Margin="1,1,1,0"></Border>
<Label x:Name="Progress" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" FontWeight="Bold" Foreground="White" Opacity=".7" Content="{Binding Path=Value, RelativeSource={RelativeSource TemplatedParent}}"></Label>
</Grid>
<ControlTemplate.Triggers>
<EventTrigger RoutedEvent="RangeBase.ValueChanged">
<BeginStoryboard>
<Storyboard>
<DoubleAnimation
Storyboard.TargetName="???????"
Storyboard.TargetProperty="Value"
From="???????" To="???????" Duration="0:0:5" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
<Trigger Property="IsIndeterminate" Value="True">
<Setter Property="Visibility" TargetName="Progress" Value="Hidden"></Setter>
<Setter Property="Background" TargetName="PART_Indicator">
<Setter.Value>
<MultiBinding>
<MultiBinding.Converter>
<wintheme:ProgressBarHighlightConverter/>
</MultiBinding.Converter>
<Binding Source="{StaticResource GlowFXProgressAnimated}"/>
<Binding Path="ActualWidth" ElementName="BaseRectangle"/>
<Binding Path="ActualHeight" ElementName="BaseRectangle"/>
</MultiBinding>
</Setter.Value>
</Setter>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Opacity" Value=".5"></Setter>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
任何帮助将不胜感激！
答案 0 :(得分：5)
我认为这是更好的方式。
您可以创建行为来执行此操作。 （MVVM WPF）
创建课程：
class ProgresBarAnimateBehavior : Behavior<ProgressBar>
{
bool _IsAnimating = false;
protected override void OnAttached()
{
base.OnAttached();
ProgressBar progressBar = this.AssociatedObject;
progressBar.ValueChanged += ProgressBar_ValueChanged;
}
private void ProgressBar_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
if (_IsAnimating)
return;
_IsAnimating = true;
DoubleAnimation doubleAnimation = new DoubleAnimation
(e.OldValue, e.NewValue, new Duration(TimeSpan.FromSeconds(0.3)), FillBehavior.Stop);
doubleAnimation.Completed += Db_Completed;
((ProgressBar)sender).BeginAnimation(ProgressBar.ValueProperty, doubleAnimation);
e.Handled = true;
}
private void Db_Completed(object sender, EventArgs e)
{
_IsAnimating = false;
}
protected override void OnDetaching()
{
base.OnDetaching();
ProgressBar progressBar = this.AssociatedObject;
progressBar.ValueChanged -= ProgressBar_ValueChanged;
}
}
简单地用法：
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
xmlns:b="clr-namespace:YOURNAMESPACE.Behaviors"
<ProgressBar Height="7"
Value="{Binding LoadingValue}">
<i:Interaction.Behaviors>
<b:ProgresBarAnimateBehavior />
</i:Interaction.Behaviors>
</ProgressBar>
答案 1 :(得分：2)
我从未真正找到解决方案。我最后只是写自己的控件。从技术上讲，这不是问题的答案，但我想我也可以发布它。如果有人正在寻找MVVM的动画进度控制，这可能会有所帮助。
namespace Card_System.Controls
{
/// <summary>
/// Interaction logic for StatProgressBar.xaml
/// </summary>
public partial class StatProgressBar : UserControl
{
private double _trackWidth;
private bool _isAnimate;
private bool _isRefresh;
public StatProgressBar()
{
InitializeComponent();
var descriptor = DependencyPropertyDescriptor.FromProperty(ActualWidthProperty, typeof(Border));
if (descriptor != null)
{
descriptor.AddValueChanged(TrackBorder, ActualWidth_ValueChanged);
}
}
public event PropertyChangedEventHandler PropertyChanged;
private double _barValueSet;
public double BarValueSet
{
get { return _barValueSet; }
set
{
_barValueSet = value;
OnPropertyChanged("BarValueSet");
_isAnimate = true;
AnimateWidth();
}
}
public double BarValueDesired
{
get { return (double)GetValue(BarValueProperty); }
set { SetValue(BarValueProperty, value); }
}
public static readonly DependencyProperty BarValueProperty =
DependencyProperty.Register("BarValueDesired", typeof(double), typeof(StatProgressBar), new UIPropertyMetadata(0.0d, new PropertyChangedCallback(BarValueDesired_PropertyChanged)));
public double BarMaximum
{
get { return (double)GetValue(BarMaximumProperty); }
set { SetValue(BarMaximumProperty, value); }
}
public static readonly DependencyProperty BarMaximumProperty =
DependencyProperty.Register("BarMaximum", typeof(double), typeof(StatProgressBar), new UIPropertyMetadata(0.0d));
public static void BarValueDesired_PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
//Set BarValue to the value of BarValueDesired BEFORE it was just changed.
((StatProgressBar)d).BarValueSet = (double)e.OldValue;
}
public Brush BarColor
{
get { return (Brush)GetValue(BarColorProperty); }
set { SetValue(BarColorProperty, value); }
}
public static readonly DependencyProperty BarColorProperty =
DependencyProperty.Register("BarColor", typeof(Brush), typeof(StatProgressBar), new UIPropertyMetadata(Brushes.White, new PropertyChangedCallback(BarColor_PropertyChanged)));
public static void BarColor_PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
((StatProgressBar)d).BarFill.Background = (Brush)e.NewValue;
}
private void ActualWidth_ValueChanged(object a_sender, EventArgs a_e)
{
_trackWidth = TrackBorder.ActualWidth;
_isRefresh = true;
AnimateWidth();
}
public void AnimateWidth()
{
if (_isAnimate && _isRefresh)
{
double StartPoint = new double();
double EndPoint = new double();
double PercentEnd = new double();
double PercentStart = new double();
PercentStart = BarValueSet / BarMaximum;
StartPoint = _trackWidth * PercentStart;
PercentEnd = BarValueDesired / BarMaximum;
EndPoint = _trackWidth * PercentEnd;
DoubleAnimation animation = new DoubleAnimation(StartPoint, EndPoint, TimeSpan.FromSeconds(3));
this.BarFill.BeginAnimation(Border.WidthProperty, animation);
}
else return;
}
protected void OnPropertyChanged(string name)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(name));
}
}
}
}
这是XAML：
<Grid>
<Grid MinHeight="14" MinWidth="20">
<Border x:Name="BaseRectangle" Background="{StaticResource BaseColor}" CornerRadius="0,0,0,0"/>
<Border x:Name="TrackBorder" BorderThickness="1" CornerRadius="0,0,0,0" BorderBrush="Black" Panel.ZIndex="20"/>
<Border x:Name="BarFill" HorizontalAlignment="Left" Opacity=".7" Background="White"/>
<Border x:Name="GlassOverlay" CornerRadius="0,0,0,0" Background="{StaticResource GlassFX}" Panel.ZIndex="10"/>
<Border x:Name="GlassOverlayBorder" BorderThickness="4" CornerRadius="0,0,0,0" BorderBrush="DarkGray" Opacity=".2" Panel.ZIndex="12"/>
</Grid>
答案 2 :(得分：1)
我知道这个问题已经解决，但我找到了一个非常好的实现，并不需要创建UserControl。它模仿＆＃34;理发杆效应＆＃34;并开箱即用：
<SolidColorBrush x:Key="ProgressBarBorderBrush" Color="Transparent" />
<SolidColorBrush x:Key="ProgressBarBackgroundBrush" Color="White" />
<SolidColorBrush x:Key="ProgressBarTrackBackgroundBrush" Color="#63D055" />
<Style x:Key="{x:Type ProgressBar}" TargetType="{x:Type ProgressBar}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ProgressBar}">
<local:ClippingBorder x:Name="BorderBackground" CornerRadius="3" BorderThickness="0"
BorderBrush="{StaticResource ProgressBarBorderBrush}"
Background="{StaticResource ProgressBarBackgroundBrush}">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Determinate" />
<VisualState x:Name="Indeterminate" />
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="PART_Track" Margin="0" BorderThickness="0" CornerRadius="3" />
<Border x:Name="PART_Indicator" Margin="0" BorderThickness="0" CornerRadius="3" HorizontalAlignment="Left"
Background="{StaticResource ProgressBarTrackBackgroundBrush}" ClipToBounds="True">
<Border x:Name="DiagonalDecorator" Width="5000">
<Border.Background>
<DrawingBrush TileMode="Tile" Stretch="None" Viewbox="0,0,1,1" Viewport="0,0,36,34" ViewportUnits="Absolute">
<DrawingBrush.RelativeTransform>
<TranslateTransform X="0" Y="0" />
</DrawingBrush.RelativeTransform>
<DrawingBrush.Drawing>
<GeometryDrawing Brush="#48C739" Geometry="M0,0 18,0 36,34 18,34 Z" />
</DrawingBrush.Drawing>
</DrawingBrush>
</Border.Background>
<Border.Triggers>
<EventTrigger RoutedEvent="FrameworkElement.Loaded">
<BeginStoryboard>
<Storyboard>
<DoubleAnimation
Storyboard.TargetProperty="(Border.Background).(DrawingBrush.RelativeTransform).(TranslateTransform.X)"
From="0" To=".36" RepeatBehavior="Forever" Duration="0:0:18" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Border.Triggers>
</Border>
</Border>
</Grid>
</local:ClippingBorder>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
只需根据自己的喜好编辑速度和颜色。
答案 3 :(得分：0)
我在另一个论坛发布了类似的概念，下面提到了链接。我希望这会对你有所帮助。
http://www.codeproject.com/Tips/837994/WPF-Preloader-Control
干杯