Silverlight 没有 XAML - 图像不会呈现 [英] Silverlight Without XAML - Images Will Not Render

问题描述

我有一个 Silverlight 应用程序，我没有在其中使用 XAML.我在 Application_Startup 中有一个带有以下代码的基本应用程序:

I have a Silverlight application in which I'm not using XAML. I have a basic application with the following code in Application_Startup:

private void Application_Startup(object sender, StartupEventArgs e)
{
     Grid g = new Grid();
     g.Children.Add(new Image { Source = new System.Windows.Media.Imaging.BitmapImage(new Uri("http://sstatic.net/so/img/sprites.png", UriKind.Absolute)) });
     this.RootVisual = g;
}

此代码不会渲染指定的图像.但是，如果修改 App.Xaml 文件以在 Xaml 中定义 RootVisual，则以下工作:

This code will not render the specified image. If however, the App.Xaml file is modified to define the RootVisual in the Xaml the following works:

xml:

<Application.RootVisual>
    <Grid>
    </Grid>
</Application.RootVisual>

代码:

private void Application_Startup(object sender, StartupEventArgs e)
{
     ((Grid)this.RootVisual).Children.Add(new Image { Source = new System.Windows.Media.Imaging.BitmapImage(new Uri("http://sstatic.net/so/img/sprites.png", UriKind.Absolute)) });
}

我不明白为什么一个会奏效而另一个不行.我也有使用 UserControl 的相同行为(当然使用 Content 而不是 Childern).

I don't see why one would work and the other not. I have the same behavior using a UserControl as well (using Content instead of Childern of course).

据我了解，应该没有 XAML 要求.有什么我遗漏的吗?

From what I understand, there should be not XAML requirement. Is there something I'm missing?

推荐答案

不同的是在第一种情况下，您将 RootVisual 设置为 Grid，但在第二个你的网格是一个子元素.

The difference is in the first case you are setting the RootVisual to be a Grid, but in the second your grid is a child element.

在 RootVisual 属性，它显示了以下示例:

On the MSDN page for the RootVisual property it shows the following example:

this.RootVisual = new Page();

因此，如果您创建一个 Page，然后将您的 Grid 添加到该页面，它应该可以工作.

so if you create a Page and then add your Grid to that page it should work.

Page page = new Page();
page.Content = g;
this.RootVisual = page;

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