Xamarin XAML问题：在xmlns命名空间中找不到继承类型

Question

I want a base class for my Popups to inherit from, that handles callbacks.

My approach: Create a class ("CallbackPopup") that inherits from PopupPage ( https://github.com/rotorgames/Rg.Plugins.Popup ) Create XAML+CS files that inherit from CallbackPopup

CallbackPopup: (My base class for my custom popups)

using Rg.Plugins.Popup.Pages;

namespace MyProject
{
    public class CallbackPopup : PopupPage
    {
        //[...]
    }
}

Inheriting Class - XAML:

<?xml version="1.0" encoding="utf-8" ?>
<myproject:CallbackPopup xmlns="http://xamarin.com/schemas/2014/forms" <!-- throws the error -->
                                xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                            xmlns:myproject="clr-namespace:MyProject;assembly=MyProject"
                            x:Class="MyProject.Layout.Popups.InheritingPopup">
    <CallbackPopup.Content>
       <!-- [...] -->
    </CallbackPopup.Content>
</myproject:CallbackPopup>

Inheriting Class - CS:

using Rg.Plugins.Popup.Services;
using System;
using Xamarin.Forms.Xaml;

namespace MyProject.Layout.Popups
{
    [XamlCompilation(XamlCompilationOptions.Compile)]
    public partial class InheritingPopup: CallbackPopup
    {

    public InheritingPopup()
    {
        InitializeComponent();
    }

  //  [...]
}

Error:

Type CallbackPopup not found in xmlns http://xamarin.com/schemas/2014/forms

I have tested the functionallity of the Popups and it has been successful. However creating it as a base class and make other popups inherit from it is not working as my error states. Am I missing something in the XAML declarations, or is inheriting from RG Plugins PopupPage causing the issue?

http://www.burkharts.net/apps/blog/the-secret-life-of-a-xaml-page/ states: "You cannot derive a Xaml defined Page from another Xaml defined page (unless they only define resources and no content)" May that be the cause of the problem? I don't know, if the RG Plugins PopupPages are Xaml defined pages that define more than resources and content.

Thanks for your support!

Answer 1

Well you should put myproject namespace when you initialize CallbackPopup.Content . That's what error is trying to tell you about :)

Something like this:

<myproject:CallbackPopup.Content>
       <!-- [...] -->
</myproject:CallbackPopup.Content>