添加"Android.Views.ViewGroup"到Xamarin XAML页面 [英] Adding an "Android.Views.ViewGroup" to a Xamarin XAML page

问题描述

在向XAML页面添加Android.Views.ViewGroup时，我需要一些帮助.

I need some help with adding an Android.Views.ViewGroup to a XAML page.

我有一个Xamarin项目，其解决方案结构如下:

I have a Xamarin project with a solution structure that looks like this:

• App1
  • /ViewModels
    • /MyPageViewModel.cs
    • App1
      • /ViewModels
        • /MyPageViewModel.cs
        • /MyPageView.xaml
          • /MyPageView.xaml.cs
          • /MyPageView.xaml
            • /MyPageView.xaml.cs
            • /MainActivity.cs
            • /MainApplication.cs
            • /瓶
              • /customViewGroup.aar
              • /Jars
                • /customViewGroup.aar

                请注意我使用Xamarin Android绑定库添加到解决方案中的customViewGroup.aar.

                Note the customViewGroup.aar that I've added to the solution using a Xamarin Android Binding Library.

                AAR文件包含一个我想在MyPage.xaml上显示的Android.Views.ViewGroup类，但是我不知道该怎么做.我似乎找不到适合此确切用例的指南或代码示例(也找不到涉及在Xamarin XAML页面上添加简单的Android.Views.View的指南或代码示例.)

                The AAR file contains an Android.Views.ViewGroup class that I'd like to show on MyPage.xaml but I have no clue how to do it. I can't seem to find a guide or code sample that fits this exact use case (nor can I find one that involves adding a simple Android.Views.View to a Xamarin XAML page).

                我找到了将Android.Views.ViewGroup添加到本机Android应用程序(使用Java和XML)的示例，但是没有显示如何将其添加到Xamarin XAML页面的示例.

                I've found examples of adding an Android.Views.ViewGroup to a native Android application (using Java and XML) but nothing that shows how to add it to a Xamarin XAML page.

                请帮助！

                我包含一些源代码，因此您可以看到我尝试过的内容:

                I'm including some source code so you can see what I've tried:

                MyPage.xaml

                MyPage.xaml

                <ContentPage 
                    xmlns="http://xamarin.com/schemas/2014/forms"
                    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                    x:Class="App1.Views.MyPage"
                    xmlns:vm="clr-namespace:App1.ViewModels;"
                    xmlns:androidWidget="clr-namespace:Com.CustomAAR;assembly=Com.CustomAAR;targetPlatform=Android"
                    xmlns:formsAndroid="clr-namespace:Xamarin.Forms;assembly=Xamarin.Forms.Platform.Android;targetPlatform=Android"
                    Title="{Binding Title}">
                    <ContentPage.Content>
                        <ContentView x:Name="contentViewParent">
                            <androidWidget:MyCustomViewGroup x:Arguments="{x:Static formsandroid:Forms.Context}"> 
                            </androidWidget:MyCustomViewGroup>
                        </ContentView>
                        <!--<ContentView 
                            IsVisible="True"
                            IsEnabled="True"
                            BindingContext="{Binding MyCustomViewGroup}">
                        </ContentView>-->
                    </ContentPage.Content>
                </ContentPage>
                

                MyPage.xaml.cs

                MyPage.xaml.cs

                public partial class MyPage : ContentPage
                {
                    MyCustomViewGroupModel viewModel;
                
                    public MyPage()
                    {
                        InitializeComponent ();
                    }
                
                    public MyPage(MyCustomViewGroupModel viewModel)
                    {
                        InitializeComponent();
                
                #if __ANDROID__
                        NativeViewWrapper wrapper = (NativeViewWrapper)contentViewParent.Content;
                        MyCustomViewGroup myCustomViewGroup = (MyCustomViewGroup)wrapper.NativeView;
                
                        //myCustomViewGroup = new MyCustomViewGroup(Android.App.Application.Context);
                
                        myCustomViewGroup.SomeAction("");
                #endif
                
                        BindingContext = this.viewModel = viewModel;
                    }
                }
                

                推荐答案

                要将本地控件包含在Xamarin.Forms页面中，您需要创建一个自定义控件和平台渲染器.有关完整的演练，请参见官方文档

                To include native controls in your Xamarin.Forms page you will need to create a custom control and platform renderer. See the official documentation for full walkthrough.

                首先，您首先要在共享项目中声明一个新控件:

                In a gist, you first you declare a new control in your shared project:

                public class MyCustomViewControl : View
                {
                
                }
                

                现在，在Android项目中，您将创建一个自定义渲染器，该渲染器将使用您的自定义Android视图进行本机显示:

                Now in the Android project you create a custom renderer, that will use your custom Android view to display natively:

                public class MyCustomViewRenderer : ViewRenderer<MyCustomViewControl, MyCustomViewGroup>
                {
                    MyCustomViewGroup viewGroup;
                
                    public MyCustomViewRenderer(Context context) : base(context)
                    {
                    }
                
                    protected override void OnElementChanged(ElementChangedEventArgs<MyCustomViewControl> e)
                    {
                        base.OnElementChanged(e);
                
                        if (Control == null)
                        {
                            viewGroup= new MyCustomViewGroup(Context);
                            SetNativeControl(viewGroup);
                        }
                    }
                }
                

                您还将使用渲染器在本机端设置事件等.

                You will also use the renderer to setup events, etc. on the native side.

                渲染器可以被Xamarin.Forms识别和注册，这要归功于该属性，该属性可以与Renderer在同一文件中，位于名称空间上方:

                The renderer is recognized and registered by Xamarin.Forms thanks to the attribute, that can be in the same file as the Renderer, above the namespace:

                [assembly: ExportRenderer (typeof(MyCustomViewControl), typeof(MyCustomViewRenderer))]
                

                这篇关于添加"Android.Views.ViewGroup"到Xamarin XAML页面的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！