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本文介绍了Xamarin.Forms：如何从Web API数据填充饼图？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 大家好。我创建一个Xamarin.Forms便携式应用程序。我现在正在编写一个包含静态数据的PieChart（OxyPlot）。 我想要的是有一个动态数据。意思是，数据应该来自我的数据库。 我已经能够从我的数据库中检索数据，并将其作为列表显示在我正在使用 Web Api ： ClientListPage.xaml pre> <？xml version =1.0encoding =utf-8？> < ContentPage xmlns =http://xamarin.com/schemas/2014/forms xmlns：x =http://schemas.microsoft.com/winfx/2009/xamlX：类=XamarinFormsDemo.Views.ClientListPage的xmlns：的ViewModels =CLR的命名空间：XamarinFormsDemo.ViewModels;装配= XamarinFormsDemo的xmlns：控制=CLR的命名空间：ImageCircle.Forms .Plugin.Abstractions; assembly = ImageCircle.Forms.Plugin.Abstractions BackgroundImage =bg3.jpg Title =Client List1> < StackLayout> < SearchBar Placeholder =SearchText ={Binding Keyword}SearchCommand ={Binding SearchCommand}x：Name =txtSearch/& < ListView控件的ItemsSource ={结合CustomerList，模式=双向} HasUnevenRows =真 IsPullToRefreshEnabled =真X：NAME =ListView控件> < ListView.ItemTemplate> < DataTemplate> < ViewCell> < Grid Padding =10RowSpacing =10ColumnSpacing =5> < Grid.RowDefinitions> < RowDefinition Height =Auto/> < RowDefinition Height =*/> < /Grid.RowDefinitions> < Grid.ColumnDefinitions> < ColumnDefinition Width =Auto/> < ColumnDefinition Width =*/> < /Grid.ColumnDefinitions> <控制：CircleImage来源=的icon.png HeightRequest =66 HorizontalOptions =CenterAndExpand看点=AspectFill WidthRequest =66 Grid.RowSpan =2 /> <标签Grid.Column =1文本={结合CUSTOMER_NAME} TEXTCOLOR =＃ 24e97d FontSize =24/> 将;标签Grid.Column =1 Grid.Row =1文本={结合CUSTOMER_CODE} TextColor =White FontSize =18 Opacity =0.6/> <标签Grid.Column =1 Grid.Row =2文本={结合CUSTOMER_MOBILE_NUMBER} TEXTCOLOR =White FontSize =18 Opacity =0.6/> <标签Grid.Column =1 Grid.Row =3文本={结合CUSTOMER_EMAIL_ADDRESS} TEXTCOLOR =White FontSize =18 Opacity =0.6/> < / Grid> < / ViewCell> < / DataTemplate> < /ListView.ItemTemplate> < / ListView> < / StackLayout> < / ContentPage> ClientListPage.xaml.cs 使用Newtonsoft.Json; 使用OxyPlot; using OxyPlot.Series; using System; using System.Collections.Generic; using System.Linq; using System.Net.Http; 使用System.Net.Http.Headers; using System.Text; using System.Threading.Tasks; using System.Windows.Input; using Xamarin.Forms; using XamarinFormsDemo.Models; using XamarinFormsDemo.ViewModels; 命名空间XamarinFormsDemo.Views {公共部分类ClientListPage：ContentPage { CustomerVM视图模型; public ClientListPage（） { NavigationPage.SetHasNavigationBar（this，true）; InitializeComponent（）; viewModel = new CustomerVM（）; BindingContext = viewModel; } 异步覆盖protected void OnAppearing（） { base.OnAppearing（）; var json = await GetCustomerAsync（）; var customers = JsonConvert.DeserializeObject< Customer []>（json）; foreach（Customer c in customers） viewModel.CustomerList.Add（c）; } async任务< string> GetCustomerAsync（） { var client = new HttpClient（）; client.BaseAddress = new Uri（http://192.168.1.11:50857/）; client.DefaultRequestHeaders.Accept.Clear（）; client.DefaultRequestHeaders.Accept.Add（new MediaTypeWithQualityHeaderValue（application / json））; HttpResponseMessage response = await client.GetAsync（api / Customer）; if（response.IsSuccessStatusCode） { return await response.Content.ReadAsStringAsync（）; } else return response.ReasonPhrase; } } } CustomerVM.cs using System.Collections.Generic; using System.Collections.ObjectModel; using System.ComponentModel; 使用System.Diagnostics; using System.Linq; using System.Net.Http; using System.Runtime.CompilerServices; using System.Text; using System.Threading.Tasks; using System.Windows.Input; using Xamarin.Forms; using XamarinFormsDemo.Models; 使用XamarinFormsDemo.Services; using XamarinFormsDemo.Views; 命名空间XamarinFormsDemo.ViewModels { public class CustomerVM：INotifyPropertyChanged { private ObservableCollection<客户> _customerList; //保留所有客户 private ObservableCollection< Customer> _searchedCustomerList; //保留副本以供搜索 private Customer _selectedCustomer = new Customer（）; private string _keyword =; public string关键字 { get { return _keyword; } set { this._keyword = value; //关键字改变后我们过滤Employees // Filter（）; } } public ObservableCollection< Customer> CustomerList { get { return _customerList; } set { _customerList = value; OnPropertyChanged（）; } } public CustomerVM（） { CustomerList = new ObservableCollection< Customer> } 公共事件PropertyChangedEventHandler PropertyChanged; protected virtual void OnPropertyChanged（[CallerMemberName] string propertyName = null） { var handler = PropertyChanged; if（handler！= null）handler（this，new PropertyChangedEventArgs（propertyName））; } } } 时间，我需要在一个PieChart中做。 我真的不知道该怎么做。但我认为我从上面的WEB API检索数据的方式具有相似性，我将如何做到这一点在我的图表。希望你能帮助我。 非常感谢。这些是我的一些代码： SalesPerProductViewModel.cs 使用OxyPlot; 使用OxyPlot.Annotations; using OxyPlot.Axes; using OxyPlot.Series; using System; using System.Collections.Generic; using System.Collections.ObjectModel; using System.ComponentModel; using System.Linq; using System.Runtime.CompilerServices; using System.Text; using System.Threading.Tasks; using XamarinFormsDemo.Models; namespace XamarinFormsDemo.ViewModels { public class SalesPerProductViewModel：INotifyPropertyChanged { private ObservableCollection< Sales> _salesList; //保存所有客户 public ObservableCollection< Sales> SalesPerProductModel { get { return _salesList; } set { _salesList = value; OnPropertyChanged（）; } } 公共SalesPerProductViewModel（） { SalesPerProductModel =新的ObservableCollection<销售及GT;（）; } 公共事件PropertyChangedEventHandler PropertyChanged; 保护无效OnPropertyChanged（[CallerMemberName]字符串参数propertyName = NULL） {的PropertyChanged .Invoke（这一点，新PropertyChangedEventArgs（propertyName的））？; } } } b $ b SalesPerProductPage.xaml （应显示动态图表） <？xml version =1.0encoding =utf-8？> < ContentPage的xmlns =http://xamarin.com/schemas/2014/forms的xmlns：X =http://schemas.microsoft.com/winfx/2009/xaml的xmlns：氧=CLR的命名空间：OxyPlot.Xamarin.Forms;装配= OxyPlot.Xamarin.Forms的xmlns：的ViewModels =CLR的命名空间：XamarinFormsDemo.ViewModels;装配= XamarinFormsDemox：Class =XamarinFormsDemo.Views.SalesPerProductPage BackgroundImage =bg3.jpg Title =Sales Per Product> < ContentPage.BindingContext> < ViewModels：SalesPerProductViewModel /> < /ContentPage.BindingContext> < Label Text =TOTAL SALES LABEL HERE！ TextColor =＃24e97d/> < oxy：PlotView Model ={Binding SalesPerProductModel}/> < / ContentPage> SalesPerProductPage.xaml.cs 使用OxyPlot; using OxyPlot.Xamarin.Forms; using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using XamarinFormsDemo.ViewModels; using Xamarin.Forms; using XamarinFormsDemo.Models; 使用Newtonsoft.Json; using System.Net.Http; 使用System.Net.Http.Headers; using OxyPlot.Series; 命名空间XamarinFormsDemo.Views {公共部分类SalesPerProductPage：ContentPage {私人PlotModel modelForSales; SalesPerProductViewModel viewModelforSales; public SalesPerProductPage（） { InitializeComponent（）; viewModelforSales = new SalesPerProductViewModel（）; BindingContext = viewModelforSales; } // SalesPerProductPage结束（） 异步覆盖保护无效OnAppearing（） {群。 OnAppearing（）; var json = await GetSalesPerProductAsync（）; var salesPerProduct = JsonConvert.DeserializeObject< Sales []>（json）; modelForSales =新PlotModel {标题=销售每产品， TitleColor = OxyColors.Teal， TitleFontSize = 30， TextColor = OxyColors.White， DefaultFont =Arial Black， DefaultFontSize = 20 }; dynamic seriesP2 = new PieSeries {StrokeThickness = 2.0，InsideLabelPosition = 0.8，AngleSpan = 360，StartAngle = 0}; 的foreach（在salesPerProduct销售三） { seriesP2.Slices.Add（新PieSlice（c.PRODUCT_CODE，c.PRODUCT_ID）{IsExploded =假，填写= OxyColors。 Teal}）; } modelForSales.Series.Add（seriesP2）; this.SalesPerProductModel = modelForSales; } public PlotModel SalesPerProductModel {get;私人集} async任务< string> GetSalesPerProductAsync（） { var client = new HttpClient（）; client.BaseAddress = new Uri（http://192.168.1.11:50857/）; client.DefaultRequestHeaders.Accept.Clear（）; client.DefaultRequestHeaders.Accept.Add（new MediaTypeWithQualityHeaderValue（application / json））; HttpResponseMessage response = await client.GetAsync（api / Sales）; if（response.IsSuccessStatusCode） { return await response.Content.ReadAsStringAsync（）; } else return response.ReasonPhrase; } } } Sales.cs using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; 命名空间XamarinFormsDemo.Models { public class Sales { public int Id {get;组; } public int ORDER_ID {get;组; } public int ORDER_DETAILS_ID {get;组; } public int PRODUCT_ID {get;组; } public string PRODUCT_CODE {get;组; } public string NET_AMOUNT {get;组; } } } 解决方案您将 PlotModel 分配给一个本地变量。您必须将其分配给您的 ViewModel 。这是您重构的工作代码： SalesPerProductPage.xaml ： <？xml version =1.0encoding =utf-8？> < ContentPage xmlns =http://xamarin.com/schemas/2014/forms xmlns：x =http://schemas.microsoft.com/winfx/2009/xaml xmlns：oxy =clr-namespace：OxyPlot.Xamarin.Forms; assembly = OxyPlot.Xamarin.Forms xmlns：local =clr-namespace：App1x：Class =App1 .SalesPerProductPage> < ContentPage.Content> < oxy：PlotView Model ={Binding SalesPerProductModel}>< / oxy：PlotView> < /ContentPage.Content> < / ContentPage> SalesPerProductPage.xaml.cs ： public partial class SalesPerProductPage：ContentPage { public SalesPerProductViewModel viewModelforSales {get;组; } public SalesPerProductPage（） { InitializeComponent（）; viewModelforSales = new SalesPerProductViewModel（）; BindingContext = viewModelforSales; } async protected override void OnAppearing（） { base.OnAppearing（）; var json = await GetSalesPerProductAsync（）; var salesPerProduct = JsonConvert.DeserializeObject< Sales []>（json）; PlotModel modelForSales = new PlotModel { Title =Sales Per Product， TitleColor = OxyColors.Teal， TitleFontSize = 30， TextColor = OxyColors.White， DefaultFont =Arial Black， DefaultFontSize = 20 }; dynamic seriesP2 = new PieSeries {StrokeThickness = 2.0，InsideLabelPosition = 0.8，AngleSpan = 360，StartAngle = 0，FontSize = 24}; foreach（salesPerProduct中的Sales c） { seriesP2.Slices.Add（new PieSlice（c.PRODUCT_CODE，c.PRODUCT_ID））; } modelForSales.Series.Add（seriesP2）; viewModelforSales.SalesPerProductModel = modelForSales; } async任务< string> GetSalesPerProductAsync（） { var client = new HttpClient（）; client.BaseAddress = new Uri（http://10.0.0.17:64550/）; client.DefaultRequestHeaders.Accept.Clear（）; client.DefaultRequestHeaders.Accept.Add（new MediaTypeWithQualityHeaderValue（application / json））; HttpResponseMessage response = await client.GetAsync（api / Sales）; if（response.IsSuccessStatusCode） { return await response.Content.ReadAsStringAsync（）; } else return response.ReasonPhrase; } } SalesPerProductViewModel： p> public class SalesPerProductViewModel：INotifyPropertyChanged { public event PropertyChangedEventHandler PropertyChanged = delegate {}; private PlotModel _salesPerProductModel; public PlotModel SalesPerProductModel { get { return _salesPerProductModel; } set { if（value！= _salesPerProductModel） { _salesPerProductModel = value; PropertyChanged（this，new PropertyChangedEventArgs（SalesPerProductModel））; } } } public SalesPerProductViewModel（） {} } Good Day Everyone. I'm creating a Xamarin.Forms Portable Application. And I'm currently coding a PieChart (OxyPlot) that contains static data.What I want to do is to have a Dynamic Data in every Pie Slice I have. Meaning, the data should come from my database. I'm already able to retrieved data from my database and display it as a List in the Mobile Application that I'm creating using Web Api like this one :ClientListPage.xaml<?xml version="1.0" encoding="utf-8" ?><ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="XamarinFormsDemo.Views.ClientListPage" xmlns:ViewModels="clr-namespace:XamarinFormsDemo.ViewModels;assembly=XamarinFormsDemo" xmlns:controls="clr-namespace:ImageCircle.Forms.Plugin.Abstractions;assembly=ImageCircle.Forms.Plugin.Abstractions" BackgroundImage="bg3.jpg" Title="Client List1"><StackLayout> <SearchBar Placeholder="Search" Text="{Binding Keyword}" SearchCommand="{Binding SearchCommand}" x:Name="txtSearch" /> <ListView ItemsSource="{Binding CustomerList, Mode=TwoWay}" HasUnevenRows="True" IsPullToRefreshEnabled="True" x:Name="listView"> <ListView.ItemTemplate> <DataTemplate> <ViewCell> <Grid Padding="10" RowSpacing="10" ColumnSpacing="5"> <Grid.RowDefinitions> <RowDefinition Height="Auto"/> <RowDefinition Height="*"/> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto"/> <ColumnDefinition Width="*"/> </Grid.ColumnDefinitions> <controls:CircleImage Source="icon.png" HeightRequest="66" HorizontalOptions="CenterAndExpand" Aspect="AspectFill" WidthRequest="66" Grid.RowSpan="2" /> <Label Grid.Column="1" Text="{Binding CUSTOMER_NAME}" TextColor="#24e97d" FontSize="24"/> <Label Grid.Column="1" Grid.Row="1" Text="{Binding CUSTOMER_CODE}" TextColor="White" FontSize="18" Opacity="0.6"/> <Label Grid.Column="1" Grid.Row="2" Text="{Binding CUSTOMER_MOBILE_NUMBER}" TextColor="White" FontSize="18" Opacity="0.6"/> <Label Grid.Column="1" Grid.Row="3" Text="{Binding CUSTOMER_EMAIL_ADDRESS}" TextColor="White" FontSize="18" Opacity="0.6"/> </Grid> </ViewCell> </DataTemplate> </ListView.ItemTemplate> </ListView></StackLayout></ContentPage>ClientListPage.xaml.csusing Newtonsoft.Json;using OxyPlot;using OxyPlot.Series;using System;using System.Collections.Generic;using System.Linq;using System.Net.Http;using System.Net.Http.Headers;using System.Text;using System.Threading.Tasks;using System.Windows.Input;using Xamarin.Forms;using XamarinFormsDemo.Models;using XamarinFormsDemo.ViewModels;namespace XamarinFormsDemo.Views{ public partial class ClientListPage : ContentPage { CustomerVM viewModel; public ClientListPage() { NavigationPage.SetHasNavigationBar(this, true); InitializeComponent(); viewModel = new CustomerVM(); BindingContext = viewModel; } async override protected void OnAppearing() { base.OnAppearing(); var json = await GetCustomerAsync(); var customers = JsonConvert.DeserializeObject<Customer[]>(json); foreach (Customer c in customers) viewModel.CustomerList.Add(c); } async Task<string> GetCustomerAsync() { var client = new HttpClient(); client.BaseAddress = new Uri("http://192.168.1.11:50857/"); client.DefaultRequestHeaders.Accept.Clear(); client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json")); HttpResponseMessage response = await client.GetAsync("api/Customer"); if (response.IsSuccessStatusCode) { return await response.Content.ReadAsStringAsync(); } else return response.ReasonPhrase; } }}CustomerVM.csusing System;using System.Collections.Generic;using System.Collections.ObjectModel;using System.ComponentModel;using System.Diagnostics;using System.Linq;using System.Net.Http;using System.Runtime.CompilerServices;using System.Text;using System.Threading.Tasks;using System.Windows.Input;using Xamarin.Forms;using XamarinFormsDemo.Models;using XamarinFormsDemo.Services;using XamarinFormsDemo.Views;namespace XamarinFormsDemo.ViewModels{ public class CustomerVM : INotifyPropertyChanged { private ObservableCollection<Customer> _customerList; // keep all customers private ObservableCollection<Customer> _searchedCustomerList; // keep a copy for searching private Customer _selectedCustomer = new Customer(); private string _keyword = ""; public string Keyword { get { return _keyword; } set { this._keyword = value; // while keyword changed we filter Employees //Filter(); } } public ObservableCollection<Customer> CustomerList { get { return _customerList; } set { _customerList = value; OnPropertyChanged(); } } public CustomerVM() { CustomerList = new ObservableCollection<Customer>(); } public event PropertyChangedEventHandler PropertyChanged; protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null) { var handler = PropertyChanged; if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName)); } }}But this time, I need to do it in a PieChart. I really don't have an idea how to do this. But I think the way I retrieved the data from my WEB API above has similarity on how am I going to do this in my chart. Hope you can help me.Thanks a lot. These are some of my codes :SalesPerProductViewModel.csusing OxyPlot;using OxyPlot.Annotations;using OxyPlot.Axes;using OxyPlot.Series;using System;using System.Collections.Generic;using System.Collections.ObjectModel;using System.ComponentModel;using System.Linq;using System.Runtime.CompilerServices;using System.Text;using System.Threading.Tasks;using XamarinFormsDemo.Models;namespace XamarinFormsDemo.ViewModels{ public class SalesPerProductViewModel : INotifyPropertyChanged { private ObservableCollection<Sales> _salesList; // keep all customers public ObservableCollection<Sales> SalesPerProductModel { get { return _salesList; } set { _salesList = value; OnPropertyChanged(); } } public SalesPerProductViewModel() { SalesPerProductModel = new ObservableCollection<Sales>(); } public event PropertyChangedEventHandler PropertyChanged; protected void OnPropertyChanged([CallerMemberName] string propertyName = null) { PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName)); } }}SalesPerProductPage.xaml (This is where the dynamic chart should be displayed)<?xml version="1.0" encoding="utf-8" ?><ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:oxy="clr-namespace:OxyPlot.Xamarin.Forms;assembly=OxyPlot.Xamarin.Forms" xmlns:ViewModels="clr-namespace:XamarinFormsDemo.ViewModels;assembly=XamarinFormsDemo" x:Class="XamarinFormsDemo.Views.SalesPerProductPage" BackgroundImage="bg3.jpg" Title="Sales Per Product"> <ContentPage.BindingContext> <ViewModels:SalesPerProductViewModel/> </ContentPage.BindingContext> <Label Text="TOTAL SALES LABEL HERE!" TextColor="#24e97d"/> <oxy:PlotView Model="{Binding SalesPerProductModel}" /></ContentPage>SalesPerProductPage.xaml.csusing OxyPlot;using OxyPlot.Xamarin.Forms;using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using XamarinFormsDemo.ViewModels;using Xamarin.Forms;using XamarinFormsDemo.Models;using Newtonsoft.Json;using System.Net.Http;using System.Net.Http.Headers;using OxyPlot.Series;namespace XamarinFormsDemo.Views{ public partial class SalesPerProductPage : ContentPage { private PlotModel modelForSales; SalesPerProductViewModel viewModelforSales; public SalesPerProductPage() { InitializeComponent(); viewModelforSales = new SalesPerProductViewModel(); BindingContext = viewModelforSales; } //end of SalesPerProductPage() async override protected void OnAppearing() { base.OnAppearing(); var json = await GetSalesPerProductAsync(); var salesPerProduct = JsonConvert.DeserializeObject<Sales[]>(json); modelForSales = new PlotModel { Title = "Sales Per Product", TitleColor = OxyColors.Teal, TitleFontSize = 30, TextColor = OxyColors.White, DefaultFont = "Arial Black", DefaultFontSize = 20 }; dynamic seriesP2 = new PieSeries { StrokeThickness = 2.0, InsideLabelPosition = 0.8, AngleSpan = 360, StartAngle = 0 }; foreach (Sales c in salesPerProduct) { seriesP2.Slices.Add(new PieSlice(c.PRODUCT_CODE, c.PRODUCT_ID) { IsExploded = false, Fill = OxyColors.Teal }); } modelForSales.Series.Add(seriesP2); this.SalesPerProductModel = modelForSales; } public PlotModel SalesPerProductModel { get; private set; } async Task<string> GetSalesPerProductAsync() { var client = new HttpClient(); client.BaseAddress = new Uri("http://192.168.1.11:50857/"); client.DefaultRequestHeaders.Accept.Clear(); client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json")); HttpResponseMessage response = await client.GetAsync("api/Sales"); if (response.IsSuccessStatusCode) { return await response.Content.ReadAsStringAsync(); } else return response.ReasonPhrase; } }}Sales.csusing System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace XamarinFormsDemo.Models{ public class Sales { public int Id { get; set; } public int ORDER_ID { get; set; } public int ORDER_DETAILS_ID { get; set; } public int PRODUCT_ID { get; set; } public string PRODUCT_CODE { get; set; } public string NET_AMOUNT { get; set; } }} 解决方案 You're assigning your PlotModel to a local variable. You must assign it to your ViewModel. Here's your refactored working code:SalesPerProductPage.xaml:<?xml version="1.0" encoding="utf-8" ?><ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:oxy="clr-namespace:OxyPlot.Xamarin.Forms;assembly=OxyPlot.Xamarin.Forms" xmlns:local="clr-namespace:App1" x:Class="App1.SalesPerProductPage"> <ContentPage.Content> <oxy:PlotView Model="{Binding SalesPerProductModel}"></oxy:PlotView> </ContentPage.Content></ContentPage>SalesPerProductPage.xaml.cs:public partial class SalesPerProductPage : ContentPage{ public SalesPerProductViewModel viewModelforSales { get; set; } public SalesPerProductPage() { InitializeComponent(); viewModelforSales = new SalesPerProductViewModel(); BindingContext = viewModelforSales; } async protected override void OnAppearing() { base.OnAppearing(); var json = await GetSalesPerProductAsync(); var salesPerProduct = JsonConvert.DeserializeObject<Sales[]>(json); PlotModel modelForSales = new PlotModel { Title = "Sales Per Product", TitleColor = OxyColors.Teal, TitleFontSize = 30, TextColor = OxyColors.White, DefaultFont = "Arial Black", DefaultFontSize = 20 }; dynamic seriesP2 = new PieSeries { StrokeThickness = 2.0, InsideLabelPosition = 0.8, AngleSpan = 360, StartAngle = 0, FontSize = 24 }; foreach (Sales c in salesPerProduct) { seriesP2.Slices.Add(new PieSlice(c.PRODUCT_CODE, c.PRODUCT_ID)); } modelForSales.Series.Add(seriesP2); viewModelforSales.SalesPerProductModel = modelForSales; } async Task<string> GetSalesPerProductAsync() { var client = new HttpClient(); client.BaseAddress = new Uri("http://10.0.0.17:64550/"); client.DefaultRequestHeaders.Accept.Clear(); client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json")); HttpResponseMessage response = await client.GetAsync("api/Sales"); if (response.IsSuccessStatusCode) { return await response.Content.ReadAsStringAsync(); } else return response.ReasonPhrase; }}SalesPerProductViewModel:public class SalesPerProductViewModel : INotifyPropertyChanged{ public event PropertyChangedEventHandler PropertyChanged = delegate { }; private PlotModel _salesPerProductModel; public PlotModel SalesPerProductModel { get { return _salesPerProductModel; } set { if (value != _salesPerProductModel) { _salesPerProductModel = value; PropertyChanged(this, new PropertyChangedEventArgs("SalesPerProductModel")); } } } public SalesPerProductViewModel() { }} 这篇关于Xamarin.Forms：如何从Web API数据填充饼图？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！ 10-28 16:52