Xamarin.Forms:不出现 OxyPlot 饼图

问题描述

大家好.我正在创建一个 Xamarin.Forms 便携式应用程序，我想使用 OxyPlot 在那里显示一个图表.

我遵循了 这里关于OxyPlot.但我还是有点糊涂.你能看看我遵循的过程并检查我所做的是否正确吗?这些只是我个人的理解.

这是我所做的:

1. 将 Xamarin.Forms NuGet 包更新到最新版本.
2. 在可移植和特定于平台的项目中添加 OxyPlot.Xamarin.Forms NuGet 包.
3. 我通过在 MainActivity.cs 中的 Xamarin.Forms.Forms.Init() 之后添加 OxyPlot.Xamarin.Forms.Platform.Android.PlotViewRenderer.Init(); 来初始化 OxyPlot 渲染器

4. 在便携式应用程序项目中，我将此绘图视图添加到我的 App.cs 中.

   公共应用程序(){this.MainPage = 新的 ContentPage{内容 = 新的 PlotView{模型 = 新的 PlotModel { 标题 = 你好，表单！"},VerticalOptions = LayoutOptions.Fill，Horizo​​ntalOptions = LayoutOptions.Fill，},};}

5. 在我的 XAML 页面中，我添加了这个命名空间声明:

1. 然后我在同一页面上添加了这个.

    <oxy:PlotView Model="{Binding Model1}" VerticalOptions="Center" Horizo​​ntalOptions="Center"/>

   这是整个SalesPage.xaml的代码

2. 之后，我尝试调用包含名为 PiewViewModel.cs

   的图表内容的视图模型

   使用OxyPlot；使用 OxyPlot.Series；命名空间 ExampleLibrary{公共类 PieViewModel{私人 PlotModel 模型 P1；公共 PieViewModel(){modelP1 = new PlotModel { Title = "Pie Sample1" };动态系列P1 = 新PieSeries { StrokeThickness = 2.0, InsideLabelPosition = 0.8, AngleSpan = 360, StartAngle = 0 };seriesP1.Slices.Add(new PieSlice("Africa", 1030) { IsExploded = false, Fill = OxyColors.PaleVioletRed });seriesP1.Slices.Add(new PieSlice("Americas", 929) { IsExploded = true });seriesP1.Slices.Add(new PieSlice("Asia", 4157) { IsExploded = true });seriesP1.Slices.Add(new PieSlice("Europe", 739) { IsExploded = true });seriesP1.Slices.Add(new PieSlice("Oceania", 35) { IsExploded = true });modelP1.Series.Add(seriesP1);}公共 PlotModel Model1{得到 { 返回模型 P1;}设置 { modelP1 = 值；}}}}

3. 这是我的 Android 版 MainActivity.cs

    使用系统；使用 Android.App;使用 Android.Content.PM；使用 Android.Runtime;使用 Android.Views;使用 Android.Widget;使用Android.OS；使用 ImageCircle.Forms.Plugin.Droid;命名空间 XamarinFormsDemo.Droid{[活动(标签 =XamarinFormsDemo"，图标 =@dr​​awable/recordsicon"，MainLauncher = true，ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]公共类 MainActivity : global::Xamarin.Forms.Platform.Android.FormsApplicationActivity{protected override void OnCreate(Bundle bundle){base.OnCreate(捆绑)；global::Xamarin.Forms.Forms.Init(this, bundle);OxyPlot.Xamarin.Forms.Platform.Android.PlotViewRenderer.Init();加载应用程序(新应用程序())；ImageCircleRenderer.Init();}}}

你能告诉我我做错了什么吗?图表没有出现.对像我这样的新手的任何帮助都非常感谢.非常感谢.

解决方案

你的 MainActivity 类需要派生自 AndroidActivity 而不是 FormsApplicationActivity

Good Day everyone. I'm creating a Xamarin.Forms Portable Application and I want to display there a Chart using a OxyPlot.

I followed a documentation in here about OxyPlot. But I still kinda confuse. Can you please look at the process I followed and check if what I did was right? These are just based on my own understanding.

Here's what I did :

1. Update the Xamarin.Forms NuGet packages to the latest version.
2. Add the OxyPlot.Xamarin.Forms NuGet package in both the portable and platform specific projects.
3. I initialize the OxyPlot renderers by adding OxyPlot.Xamarin.Forms.Platform.Android.PlotViewRenderer.Init(); just after the Xamarin.Forms.Forms.Init() in my MainActivity.cs

4. In the portable app project, I added this plot view to my App.cs.

   public App()
   {
       this.MainPage = new ContentPage
       {
       Content = new PlotView
       {
       Model = new PlotModel { Title = "Hello, Forms!" },
       VerticalOptions = LayoutOptions.Fill,
       HorizontalOptions = LayoutOptions.Fill,
           },
       };
   }
   

5. In my XAML page, I added this namespace declaration :

1. Then I added this on the same page.

    <oxy:PlotView Model="{Binding Model1}" VerticalOptions="Center" HorizontalOptions="Center" />
   

   Here's the code of the whole SalesPage.xaml

   <?

2. After that, I tried to call my view model that contains the content of my chart named PiewViewModel.cs

   using OxyPlot;
   using OxyPlot.Series;
   
   namespace ExampleLibrary
   {
   
       public class PieViewModel
       {
           private PlotModel modelP1;
           public PieViewModel()
       {
           modelP1 = new PlotModel { Title = "Pie Sample1" };
   
           dynamic seriesP1 = new PieSeries { StrokeThickness = 2.0,     InsideLabelPosition = 0.8, AngleSpan = 360, StartAngle = 0 };
   
           seriesP1.Slices.Add(new PieSlice("Africa", 1030) { IsExploded = false, Fill = OxyColors.PaleVioletRed });
           seriesP1.Slices.Add(new PieSlice("Americas", 929) { IsExploded = true });
           seriesP1.Slices.Add(new PieSlice("Asia", 4157) { IsExploded = true });
           seriesP1.Slices.Add(new PieSlice("Europe", 739) { IsExploded = true });
           seriesP1.Slices.Add(new PieSlice("Oceania", 35) { IsExploded = true });
   
           modelP1.Series.Add(seriesP1);
   
       }
   
       public PlotModel Model1
       {
           get { return modelP1; }
           set { modelP1 = value; }
       }
      }
    }
   

3. Here's my MainActivity.cs for Android

     using System;
     using Android.App;
     using Android.Content.PM;
     using Android.Runtime;
     using Android.Views;
     using Android.Widget;
     using Android.OS;
     using ImageCircle.Forms.Plugin.Droid;
   
     namespace XamarinFormsDemo.Droid
     {
         [Activity(Label = "XamarinFormsDemo", Icon = "@drawable/recordsicon", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
         public class MainActivity :           global::Xamarin.Forms.Platform.Android.FormsApplicationActivity
         {
             protected override void OnCreate(Bundle bundle)
   {
       base.OnCreate(bundle);
   
       global::Xamarin.Forms.Forms.Init(this, bundle);
       OxyPlot.Xamarin.Forms.Platform.Android.PlotViewRenderer.Init();
       LoadApplication(new App());
       ImageCircleRenderer.Init();
             }
         }
     }
   

Can you please tell me what I've done wrong? The chart isn't appearing. Any help to a newbie like me is highly appreciated. Thanks a lot.

解决方案

Your MainActivity class needs to derive from AndroidActivity not FormsApplicationActivity

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