在运行时加载XAML

Question

I want to load a particular piece of XAML code in runtime. Using the below code, I can load the xaml present in a txt file.

private void btnLoadXAML_Click(object sender, RoutedEventArgs e)
{
  try
  {

    string LoadedFileName = @"C:\test\sample.txt";

    //Load the file
    FileStream Fs = new FileStream(@LoadedFileName, FileMode.Open);
    Grid grdToLoad = new Grid();
    grdToLoad.Height = 210;
    grdToLoad.Width = 400;

    grdToLoad = System.Windows.Markup.XamlReader.Load(Fs) as Grid;

    grdLoadXAML.Children.Add(grdToLoad);

    Fs.Close();
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}
}

The above code will actually create a new Grid control and load the XAML present in the text file and create the controls as per the code. Consider the below code...

<Window x:Class="MyWPF.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title=" " 
    Height="270" 
    Width="420" 
    Background="{x:Null}" 
    Foreground="#FFFFFFFF" 
    ShowInTaskbar="False"
    WindowStartupLocation="CenterScreen" 
    ResizeMode="NoResize" 
    WindowStyle="None" 
    AllowsTransparency="True" 
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    mc:Ignorable="d">

The above is the "Window" tag. I just need a couple of properties of it in run time. For eg: the below code

WindowStyle="None" AllowsTransparency="True" 
xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"

I don't want the above to hard code in the xaml but to insert it in run time, how can I do that? I tried the method I mentioned initially but I get run time error.

Answer 1

XAML loaded through XamlReader has some restrictions compared to normal compiled XAML files, including not depending on code-behind, since it is just parsing rather than compiling. In your case the Window you're trying to use has the usual x:Class attribute which specifies its code-behind component. If you're just using it to load some properties you should be able to strip that attribute out, either from the saved file or by using File.ReadAllText and XamlReader.Parse to modify at runtime.