My question is very specific. Let's say I have an assembly c # and I want my assembly interfaces to be xaml. How can I create wpf forms and call them inside the assembly without being inside the executable assembly that mounts a wpf project and that the start is already predefined by app.xaml. Speaking of Form we simply create a form, instantiate it and call it a show. How can I do the same with WPF?
If you mean to show a window of type System.Windows.Window that is contained in a dll, you can achieve it with reflection.
First you have to load the dll that your form using Assembly.LoadFrom() . This method receives the path of the dll and returns an object of type Assembly :
System.Reflection.Assembly assembly = System.Reflection.Assembly.LoadFrom("ruta_dll.dll");
Then you are looking for the class that is type Window using the method Assembly#GetTypes() :
var windowsType = typeof(System.Windows.Window);
assembly.GetTypes().Where(type=> type == windowType);
Since you already have all the class that are of type Window that represents the form, you only need to initialize the instants of the same using the method Activator.CreateInstance() :
var windowInstances = windowsType.Select(x=> Activator.CreateInstance(x) as System.Windows.Window);
Then to show it you would only have to execute the method Window#Show() :
windowInstances.FirstOrDefault()?.Show();
Note that I use FirstOrDefault() since it is understood that in the library you would only have one class that inherits from System.Windows.Window . If you have several, you will have to invent a mechanism to show only the form you want.
Here is the complete code:
var windowsType = typeof(System.Windows.Window);
var windowInstances = System.Reflection.Assembly.LoadFrom("ruta_dll.dll")
.GetTypes()
.Where(type=> type == windowType)
.Select(Activator.CreateInstance);
windowInstances.FirstOrDefault()?.Show();