如何在Xamarin.Forms中正确使用Image Source属性？

我在堆栈布局中无法在内容页面上显示图像。我查看了Xamarin API文档，发现了Xamarin.Forms.Image.Source属性，但是没有示例代码来查看其编写方式。我还检查了它是如何用C＃编写的，并且似乎在文件名路径方面与我的代码匹配，但是在Xamarin中，由于这是第一次，因此可能略有不同。我目前正在通过Visual Studio 2013中的Android模拟器（Google Nexus 5）测试的代码，该代码可以正常运行，但图像未显示。

图片来源：

new Image
{
     VerticalOptions = LayoutOptions.Center,
     HorizontalOptions = LayoutOptions.Center,
     Source = "/Assets/xamarin_logo.png",
},

完整代码：

public NFCPage()
    {
        StackLayout stackLayout = new StackLayout // instantiate a StackLayout object to layout its children
        {
            Spacing = 5, // amount of spae between each child element
            //HorizontalOptions = LayoutOptions.Center,
            VerticalOptions = LayoutOptions.FillAndExpand, // defines how the elements should be laid out; fill the entire width of the content to the screen
            BackgroundColor = Color.Blue,

            Children = // gets a list of child elements
            {
                new Label
                {   
                    TextColor = Color.White,
                    BackgroundColor = Color.Red,
                    XAlign = TextAlignment.Center, // set text alignment horizontally
                    Text = "Google",
                },
                new Label
                {
                    Text = "Place your device directly at the symbol.",
                    XAlign = TextAlignment.Center,
                    TextColor = Color.White,
                },
                new Image
                {
                    VerticalOptions = LayoutOptions.Center,
                    HorizontalOptions = LayoutOptions.Center,
                    Source = "/Assets/xamarin_logo.png",
                },
                new Button
                {
                    Text = "QR Code",
                    TextColor = Color.White,
                },
                new Button
                {
                    Text = "?",
                    TextColor = Color.White,
                },
            }
        };
        Content = stackLayout; // apply stackLayout to Content
    }