为什么单击按钮后我的 Datagrid 没有填充

如何解决为什么单击按钮后我的 Datagrid 没有填充

单击 viewmodel 中的按钮后，我的 Datagrid 未填充

型号代码：

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Text;

namespace Mist_Management.SubmissionStatusBySite
{
public class Table
{
    [JsonProperty("Company")]
    public string Company { get; set; }
    [JsonProperty("DATE")]
    public string Date { get; set; }
    [JsonProperty("EODNUMBER")]
    public string EODNumber { get; set; }
    [JsonProperty("SUBSTATUS")]
    public string SubStatus { get; set; }
    [JsonProperty("DAYENDSTATUS")]
    public string DayEndStatus { get; set; }
}

public class BySite
{
    public List<Table> Table { get; set; }
 }
}

视图模型代码：

using Newtonsoft.Json;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Net.Http;
using System.Threading.Tasks;
using System.Windows.Input;
using Xamarin.Forms;
using Mist_Management.CompanyModels;
using Mist_Management.SubmissionStatusBySite;
using System;
using System.Diagnostics;

namespace Mist_Management.viewmodels
{
class SubmissionStatusBySiteviewmodel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private void OnPropertyChanged(string property)
    {
        if (PropertyChanged != null)
            PropertyChanged(this,new PropertyChangedEventArgs(property));
    }

    public ObservableCollection<CompanyModels.Table> Company { get; set; }
    public ObservableCollection<SubmissionStatusBySite.Table> BySite { get; set; }

    public SubmissionStatusBySiteviewmodel()
    {
        Company = new ObservableCollection<CompanyModels.Table>();
        GetCompany();
    }

    private async void GetCompany()
    {
        string requestUrl = "https://mist.zp.co.za:6502/MIST.svc/CMP/M@H$@203@R";
        
        using (var client = new HttpClient())
        {
            HttpResponseMessage response = await client.GetAsync(requestUrl);
            if (response.StatusCode == System.Net.HttpStatusCode.OK)
            {
                string content = await response.Content.ReadAsstringAsync();
                Company root = JsonConvert.DeserializeObject<Company>(content);
                List<CompanyModels.Table> dates = root.Table;

                foreach (var item in dates)
                {
                    Company.Add(item);
                }
            }
        }
    }

    public CompanyModels.Table selectedCompany;
    public CompanyModels.Table SelectedCompany
    {
        get { return selectedCompany; }
        set
        {
            selectedCompany = value;
            OnPropertyChanged("SelectedCompany");
            Debug.WriteLine(value.Company);
        }
    }

    public DateTime _selectedFromDate;

    public DateTime SelectedFromDate
    {
        get { return _selectedFromDate; }
        set
        {
            if (_selectedFromDate == value)
                return;

            _selectedFromDate = value;
            Debug.WriteLine(_selectedFromDate);

        }
    }

    public string FromDate
    {
        get
        {
            return this.SelectedFromDate.ToString("yyyy-MM-dd");
        }
    }

    public DateTime _selectedEndDate;
    public DateTime SelectedEndDate
    {
        get { return _selectedEndDate; }
        set
        {
            if (_selectedEndDate == value)
                return;

            _selectedEndDate = value;
            Debug.WriteLine(_selectedEndDate);
        }
    }

    public string EndDate
    {
        get
        {
            return this.SelectedEndDate.ToString("yyyy-MM-dd");
        }
    }

    private async void GetData()
    {
        string requestUrl = "https://mist.zp.co.za:6502/MIST.svc/SUB2/M@H$@203@R/"
        + selectedCompany.Company + "/" + FromDate + "/" + EndDate;
        using (var client = new HttpClient())
        {
            HttpResponseMessage response = await client.GetAsync(requestUrl);
            if (response.StatusCode == System.Net.HttpStatusCode.OK)
            {
                string content = await response.Content.ReadAsstringAsync();
                BySite root = JsonConvert.DeserializeObject<BySite>(content);
                List<SubmissionStatusBySite.Table> dates = root.Table;

                foreach (var item in dates)
                {
                    BySite.Add(item);
                }
            }
        }
        Debug.WriteLine(requestUrl);
    }

    public ICommand LoadButton_Clicked 
    {
        get
        {
            return new Command(() =>
            {
                BySite = new ObservableCollection<SubmissionStatusBySite.Table>();
                GetData();
            });
        }
    }
}
}

XAML 代码：

<?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:dg="clr-namespace:Xamarin.Forms.DataGrid;assembly=Xamarin.Forms.DataGrid"
         xmlns:system="clr-namespace:System;assembly=mscorlib"
         x:Class="Mist_Management.Views.SubmissionStatusBySite"
         Title="Submission Status By Site">
<StackLayout>
    <Picker Title="Company List" ItemsSource="{Binding Company}" 
            ItemdisplayBinding="{Binding Company}"
            SelectedItem="{Binding SelectedCompany}"/>
    <Label Text="From Date"
               FontSize="Medium"/>
        <DatePicker HorizontalOptions="CenterandExpand"
                Format="yyyy-MM-dd"
                MinimumDate="2015-01-01"
                Date="{Binding SelectedFromDate}"/>
        <Label Text="To Date"
               FontSize="Medium"/>
        <DatePicker HorizontalOptions="CenterandExpand"
                x:Name="EndDate"
                Format="yyyy-MM-dd"
                MinimumDate="2015-01-01"
                Date="{Binding SelectedEndDate}"/>
        <Button Text="Load" Command="{Binding LoadButton_Clicked}"/>
    <ContentView>
        <ScrollView Orientation="Horizontal">
            <dg:DataGrid x:Name="BySiteGrid" ItemsSource="{Binding BySite}" RowHeight="70" HeaderHeight="50"
                     BorderColor="#CCCCCC" HeaderBackground="#E0E6F8">
                <x:Arguments>
                    <ListViewCachingStrategy>RetainElement</ListViewCachingStrategy>
                </x:Arguments>
                <dg:DataGrid.HeaderFontSize>
                    <OnIdiom x:TypeArguments="x:Double">
                        <OnIdiom.Tablet>15</OnIdiom.Tablet>
                        <OnIdiom.Phone>12</OnIdiom.Phone>
                    </OnIdiom>
                </dg:DataGrid.HeaderFontSize>
                <dg:DataGrid.Columns>
                    <dg:DataGridColumn Title="Company" PropertyName="Company" Width="200"/>
                    <dg:DataGridColumn Title="Date" PropertyName="Date" Width="150"/>
                    <dg:DataGridColumn Title="EOD Number" PropertyName="EODNumber" Width="150"/>
                    <dg:DataGridColumn Title="Sub Status" PropertyName="SubStatus" Width="150"/>
                    <dg:DataGridColumn Title="Day End Status" PropertyName="DayEndStatus" Width="150"/>
                </dg:DataGrid.Columns>
            </dg:DataGrid>
        </ScrollView>
    </ContentView>
</StackLayout>
</ContentPage>

内容查看代码：

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Xamarin.Forms;
using Xamarin.Forms.Xaml;

namespace Mist_Management.Views
{
[XamlCompilation(XamlCompilationoptions.Compile)]
public partial class SubmissionStatusBySite : ContentPage
{
    public SubmissionStatusBySite()
    {
        InitializeComponent();
        BindingContext = new viewmodels.SubmissionStatusBySiteviewmodel();
    }
}
}

我有在屏幕上加载的其他内容视图模型，但是当我单击按钮时，Datagrid 不想加载。 我已经尝试了我能想到的一切。我已经解决了这个问题。 任何帮助将不胜感激

解决方法

感谢 Jason 我不得不在我的数据网格上设置一个 HeightRequest