WPF 仅绘制 4 个图像（使用 C# 和 XAML）

Question

我正在尝试自定义在 MSDN 上找到的数码相框程序模板，但我发现它最多只能显示 4 张图像。如果我将第 5 个图像添加到 ArrayList，整个屏幕将变为空白。

有谁知道发生了什么以及为什么将第 4 个图像添加到 ArrayList 后会导致图像消失和窗口空白？

[后编辑：包含完整源代码]

C#源码：

using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Media.Animation;
using System.Windows.Media.Imaging;

namespace CSWPFAnimatedImage
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    int nextImageIndex;
    List<BitmapImage> images = new List<BitmapImage>();

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        // Initialize the images collection
        images.Add(new BitmapImage(new Uri("Images/image1.jpg", UriKind.Relative)));
        images.Add(new BitmapImage(new Uri("Images/image2.jpg", UriKind.Relative)));
        images.Add(new BitmapImage(new Uri("Images/image3.jpg", UriKind.Relative)));
        images.Add(new BitmapImage(new Uri("Images/image4.jpg", UriKind.Relative)));

        nextImageIndex = 2;
    }

    private void VisbleToInvisible_Completed(object sender, EventArgs e)
    {
        // Change the source of the myImage1 to the next image to be shown
        // and increase the nextImageIndex
        this.myImage1.Source = images[nextImageIndex++];

        // If the nextImageIndex exceeds the top bound of the collection,
        // get it to 0 so as to show the first image next time
        if (nextImageIndex == images.Count)
        {
            nextImageIndex = 0;
        }

        // Get the InvisibleToVisible storyboard and start it
        Storyboard sb = this.FindResource("InvisibleToVisible") as Storyboard;
        sb.Begin(this);

    }

    private void InvisibleToVisible_Completed(object sender, EventArgs e)
    {
        // Change the source of the myImage2 to the next image to be shown
        // and increase the nextImageIndex
        this.myImage2.Source = images[nextImageIndex++];

        // If the nextImageIndex exceeds the top bound of the collection,
        // get it to 0 so as to show the first image next time
        if (nextImageIndex == images.Count)
        {
            nextImageIndex = 0;
        }

        // Get the VisibleToInvisible storyboard and start it
        Storyboard sb = this.FindResource("VisibleToInvisible") as Storyboard;
        sb.Begin(this);
    }  

}
}

XAML：

<Window x:Class="CSWPFAnimatedImage.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="WPF Animated Image Sample" Height="300" Width="300" Loaded="Window_Loaded">
<Window.Resources>
    <Storyboard x:Key="VisibleToInvisible" Completed="VisbleToInvisible_Completed" >
        <DoubleAnimation Storyboard.TargetName="TransparentStop"
                        Storyboard.TargetProperty="Offset" To="0"  Duration="0:0:2"   />
        <DoubleAnimation Storyboard.TargetName="BlackStop"
                        Storyboard.TargetProperty="Offset" To="0" Duration="0:0:2"
                        />
    </Storyboard>
    <Storyboard x:Key="InvisibleToVisible" Completed="InvisibleToVisible_Completed">
        <DoubleAnimation Storyboard.TargetName="TransparentStop"
                        Storyboard.TargetProperty="Offset" To="1"  Duration="0:0:2"   />
        <DoubleAnimation Storyboard.TargetName="BlackStop"
                        Storyboard.TargetProperty="Offset" To="1" Duration="0:0:2"   />
    </Storyboard>
</Window.Resources>
<Window.Triggers>
    <EventTrigger RoutedEvent="Window.Loaded">
        <EventTrigger.Actions>
            <BeginStoryboard Storyboard="{StaticResource  VisibleToInvisible}"/>
        </EventTrigger.Actions>
    </EventTrigger>
</Window.Triggers>
<Grid Name="grid">        
    <Image x:Name="myImage2" Source="Images/image2.jpg" />
    <Image x:Name="myImage1" Source="Images/image1.jpg">
        <Image.OpacityMask>
            <LinearGradientBrush StartPoint="0,0" EndPoint="1,0">
                <GradientStop Offset="1" Color="Black" x:Name="BlackStop"/>
                <GradientStop Offset="1" Color="Transparent" x:Name="TransparentStop"/>
            </LinearGradientBrush>
        </Image.OpacityMask>
    </Image>
</Grid> </Window>

Answer 1

这里可行

images.Add(new BitmapImage(new Uri("Images/image1.jpg", UriKind.Relative)));

这不是

images.Add(new BitmapImage(new Uri("D:\\image2jpg", UriKind.Relative)));

所以。改成

images.Add(new BitmapImage(new Uri("D:\\image2jpg", UriKind.Absolute)));

当您从某处复制图像并将其粘贴到项目的图像文件夹并将其添加到图像列表中时，它会起作用。