访问C#中的嵌套XAML控件

<Grid>
    <StackPanel>
        <TextBlock x:Name="txtMessage" Text="Hello World!" />
        <Button x:Name="btnSubmit" Content="Submit" />
    </StackPanel>
</Grid>

using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml;

// 在合适的位置引用XAML文件
var xamlContent = "<Grid><StackPanel><TextBlock x:Name=\"txtMessage\" Text=\"Hello World!\" /><Button x:Name=\"btnSubmit\" Content=\"Submit\" /></StackPanel></Grid>";
var xamlRoot = (Grid)XamlReader.Load(xamlContent);

// 获取嵌套控件的实例
var txtMessage = (TextBlock)xamlRoot.FindName("txtMessage");
var btnSubmit = (Button)xamlRoot.FindName("btnSubmit");

// 对控件进行操作
txtMessage.Text = "Updated message";
btnSubmit.IsEnabled = false;