using System;

using System.Collections.Generic;

using System.Linq;

using System.Reflection;

using System.Text;

using System.Threading.Tasks;

namespace ReactiveUI

{

public class DesignModeDetector

{

/// <summary>

/// Private constructor to prevent instantiation.

/// </summary>

private DesignModeDetector() { }

static bool? isInDesignMode;

/// <summary>

/// Determines is this application is currently running in a designer.

/// </summary>

/// <returns>true if in designer; otherwise false</returns>

public static bool IsInDesignMode()

{

if (!isInDesignMode.HasValue)

{

// Check WPF Design Mode

var type = Type.GetType("System.ComponentModel.DesignerProperties, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35", false);

if (type != null) {

var mInfo = type.GetRuntimeMethods().FirstOrDefault(x => x.Name == "GetIsInDesignMode");

var dependencyObject = Type.GetType("System.Windows.DependencyObject, WindowsBase, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35", false);

if (dependencyObject != null) {

isInDesignMode = (bool)mInfo.Invoke(null, new object[] { Activator.CreateInstance(dependencyObject) });

}

} else if((type = Type.GetType("System.ComponentModel.DesignerProperties, System.Windows, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e", false)) != null) {

// Check Silverlight Design Mode

var mInfo = type.GetRuntimeMethods().FirstOrDefault(x => x.Name == "GetIsInDesignMode");

var dependencyObject = Type.GetType("System.Windows.Controls.Border, System.Windows, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e", false);

if (dependencyObject != null) {

isInDesignMode = (bool)mInfo.Invoke(null, new object[] { Activator.CreateInstance(dependencyObject) });

}

} else if ((type = Type.GetType("Windows.ApplicationModel.DesignMode, Windows, ContentType=WindowsRuntime", false)) != null) {

// check WinRT next

isInDesignMode = (bool)type.GetRuntimeProperty("DesignModeEnabled").GetMethod.Invoke(null, null);

} else {

isInDesignMode = false;

}

}

return isInDesignMode.GetValueOrDefault(false);

}

}

}