仅包含WPF

Question

我真的没有找到与此主题相关的有用信息。

假设我将自定义ProgressBar定义为UserControl：

<ProgressBar x:Class="Views.Controls.ProgressBar"
             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:local="clr-namespace:Views.Controls"
             mc:Ignorable="d" 
             d:DesignHeight="100" d:DesignWidth="300"
             Value="50">
</ProgressBar>

我想让进度条动画流畅。我找到了一些解决方案，在控件本身中使用后台代码。从MVVM开始，这绝对不是如何处理这个问题。 主要目标是直接在xaml中处理它，触发Value属性值更改，然后启动Animation。但正如我已经提到的，我找不到任何有用的资源。

按照this链接的说明操作后，条形图不会填满。我的代码：

用户控件：

<UserControl x:Class="Views.Controls.ProgressBar"
             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:Controls="clr-namespace:MahApps.Metro.Controls;assembly=MahApps.Metro"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:KBSLauncher.Views.Controls"
             mc:Ignorable="d" 
             d:DesignWidth="200">
    <Controls:MetroProgressBar x:Name="progressBar"/>
</UserControl>

背景代码：

public partial class ProgressBar: UserControl
{
    public static readonly DependencyProperty ValueProperty = DependencyProperty.Register("Value", typeof(double), typeof(ProgressBar), new PropertyMetadata(0d, ValueChanged));
    public static readonly DependencyProperty MaximumProperty = DependencyProperty.Register("Maximum", typeof(double), typeof(ProgressBar));
    public static readonly DependencyProperty MinimumProperty = DependencyProperty.Register("Minimum", typeof(double), typeof(ProgressBar));
    public static readonly DependencyProperty IsIndeterminateProperty = DependencyProperty.Register("IsIndeterminate", typeof(bool), typeof(ProgressBar));


    [Positive]
    public double Value
    {
        get
        {
            return (double) GetValue(ValueProperty);
        }

        set
        {
            SetValue(ValueProperty, value);
        }
    }

    [StrictlyPositive]
    public double Maximum
    {
        get
        {
            return progressBar.Maximum;
        }

        set
        {
            progressBar.Maximum = value;
        }
    }

    [Positive]
    public double Minimum
    {
        get
        {
            return progressBar.Minimum;
        }

        set
        {
            progressBar.Minimum = value;
        }
    }

    public bool IsIndeterminate
    {
        get
        {
            return progressBar.IsIndeterminate;
        }

        set
        {
            progressBar.IsIndeterminate = value;
        }
    }

    public ProgressBar()
    {
        InitializeComponent();
    }

    private static void ValueChanged (DependencyObject sender, DependencyPropertyChangedEventArgs args)
    {
        ProgressBar control = (ProgressBar)sender;
        control.ValueChanged();
    }

    private void ValueChanged()
    {
        DoubleAnimation animation = new DoubleAnimation();
        animation.To = Value;
        animation.Duration = new Duration(TimeSpan.FromMilliseconds(Value * 2));
        Storyboard.SetTarget(animation, progressBar);
        Storyboard.SetTargetProperty(animation, new PropertyPath(ValueProperty));
        Storyboard sb = new Storyboard();
        sb.Children.Add(animation);
        sb.Begin();
    }
}