我的示例应用程序具有以下Xaml来演示该问题:
<Page x:Class="App1.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:App1"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Background="#F5DEB3">
<Border x:Name="MyBorder"
HorizontalAlignment="Center"
VerticalAlignment="Center">
<Image Stretch="Uniform"
Width="165"
Height="100"
Source="/Assets/abstract.png" />
</Border>
</Page>
这是我的代码背后:
using Windows.UI.Composition;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Hosting;
namespace App1
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
this.Loaded += MainPage_Loaded;
}
private void MainPage_Loaded(object sender, RoutedEventArgs e)
{
var scalar = Window.Current.Compositor.CreateScalarKeyFrameAnimation();
scalar.InsertKeyFrame(1.0f, 24f);
scalar.DelayTime = TimeSpan.FromMilliseconds(1500);
scalar.Duration = TimeSpan.FromMilliseconds(3000);
var effect = new GaussianBlurEffect()
{
Name = "Blur",
Source = new CompositionEffectSourceParameter("Backdrop"),
BorderMode = EffectBorderMode.Hard,
};
var effectFactory = Window.Current.Compositor.CreateEffectFactory(effect, new[] { "Blur.BlurAmount" });
var brush = effectFactory.CreateBrush();
var sprite = Window.Current.Compositor.CreateSpriteVisual();
sprite.Brush = brush;
sprite.Size = new Vector2((float)MyBorder.ActualWidth, (float)MyBorder.ActualHeight);
ElementCompositionPreview.SetElementChildVisual(MyBorder, sprite);
var destinationBrush = Window.Current.Compositor.CreateBackdropBrush();
brush.SetSourceParameter("Backdrop", destinationBrush);
brush.StartAnimation("Blur.BlurAmount", scalar);
}
}
}
应用运行时,应该等待1.5秒钟,然后开始模糊图像。但是,在运行代码时,图像上已经设置了初始模糊(轻微模糊)。有人知道为什么吗?
答案 0 :(得分:1)
稍微更改一下代码。试试这个。我不知道为什么需要将BlurAmount
设置为零的原因,但是也许新的GaussianBlurEffect
已经将该值预置了其他值。
var effect = new GaussianBlurEffect()
{
Name = "Blur",
Source = new CompositionEffectSourceParameter("Backdrop"),
BorderMode = EffectBorderMode.Hard,
BlurAmount = 0,
};
答案 1 :(得分:0)
有关此问题的更多信息,其行为的原因以及上述答案中以BlurAmount = 0开头的原因是因为BlurAmount的默认值为3.0f: