将 collectionview 页脚绑定到数据 xamarin.forms

Question

我有一个集合视图，其中包含我使用网络 api 从 sql 服务器数据库获取的数据。 collectionview 成功填充。现在我想添加一个页脚来显示借方和贷方列的总数。但我无法让它发挥作用。这是我的代码 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="isc_alphaApp.account_details">
    <ContentPage.Content>
        <AbsoluteLayout Padding="0" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
            <StackLayout BackgroundColor="Beige" AbsoluteLayout.LayoutBounds="0, 0, 1, 1" AbsoluteLayout.LayoutFlags="All">
                <StackLayout HorizontalOptions="CenterAndExpand" VerticalOptions="CenterAndExpand">
                    <Label  HorizontalOptions="CenterAndExpand" Margin="20,20" FontAttributes="Bold" TextColor="Black" Text="" x:Name="acc_curlabel"/>
                    <CollectionView x:Name="accountdetailslst" Footer="{Binding}">
                        <CollectionView.Header>
                            <Grid Padding="2" ColumnSpacing="1" RowSpacing="1" >
                                <Grid.RowDefinitions>
                                    <RowDefinition Height="35" />

                                </Grid.RowDefinitions>
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="0.45*" />
                                    <ColumnDefinition Width="0.2*" />
                                    <ColumnDefinition Width="0.2*"/>
                                    <ColumnDefinition Width="0.5*" />
                                    <ColumnDefinition Width="0.35*" />
                                    <ColumnDefinition Width="0.35*" />
                                    <ColumnDefinition Width="0.35*" />
                                </Grid.ColumnDefinitions>

                                <Label Grid.Column="0"
                       Text="Date"
                       FontAttributes="Bold"
                                       FontSize="14"
                       LineBreakMode="TailTruncation"
                                   HorizontalOptions="Center"
                                   VerticalOptions="Center"
                                   TextColor="Black"/>
                                <Label Grid.Column="1"
                       Text="Jv#"
                       FontAttributes="Bold"
                       LineBreakMode="TailTruncation" 
                                        FontSize="14"
                                  HorizontalOptions="Center"
                                   VerticalOptions="Center"
                                    TextColor="Black"/>
                                <Label
                                 TextColor="Black"
                       Grid.Column="2"
                                     FontSize="14"
                       Text="Ref"
                       LineBreakMode="TailTruncation"
                       FontAttributes="Bold"
                              HorizontalOptions="Center"
                                   VerticalOptions="Center"
                                
                        />
                                <Label
                       Grid.Column="3"
                                     FontSize="14"
                       Text="Description"
                       LineBreakMode="TailTruncation"
                       FontAttributes="Bold"
                               HorizontalOptions="Center"
                                 TextColor="Black"
                                   VerticalOptions="Center"
                       />
                                <Label
                                     FontSize="14"
                                 TextColor="Black"
                       Grid.Column="4"
                       Text="Debit"
                       LineBreakMode="TailTruncation"
                       FontAttributes="Bold"
                               HorizontalOptions="Center"
                                   VerticalOptions="Center"
                       />
                                <Label
                                     FontSize="14"
                                 TextColor="Black"
                       Grid.Column="5"
                       Text="Credit"
                       LineBreakMode="TailTruncation"
                       FontAttributes="Bold"
                               HorizontalOptions="Center"
                                   VerticalOptions="Center"
                       />
                                <Label
                                 TextColor="Black"
                       Grid.Column="6"
                                     FontSize="14"
                       Text="Balance"
                       LineBreakMode="TailTruncation"
                       FontAttributes="Bold"
                               HorizontalOptions="Center"
                                   VerticalOptions="Center"
                       />

                            </Grid>


                        </CollectionView.Header>
                        <CollectionView.ItemTemplate>

                            <DataTemplate>
                                <Grid Padding="1" ColumnSpacing="1" RowSpacing="0">
                                    <Grid.RowDefinitions>
                                        <RowDefinition Height="40" />

                                    </Grid.RowDefinitions>
                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition Width="0.45*" />
                                        <ColumnDefinition Width="0.2*" />
                                        <ColumnDefinition Width="0.2*" />
                                        <ColumnDefinition Width="0.5*" />
                                        <ColumnDefinition Width="0.35*" />
                                        <ColumnDefinition Width="0.35*" />
                                        <ColumnDefinition Width="0.35*" />
                                    </Grid.ColumnDefinitions>

                                    <Label HorizontalOptions="Center"
                                Grid.Column="0"
                                TextColor="Black"
                       Text="{Binding jvdate}"
                      VerticalOptions="Center"
                       LineBreakMode="TailTruncation" 
                                           FontSize="12"/>

                                    <Label 
                                 Grid.Column="1"
                                 VerticalOptions="Center"
                                HorizontalOptions="Center"
                                TextColor="Black"
                       Text="{Binding jvnbr}"
                      FontSize="12"
                       LineBreakMode="TailTruncation" />

                                    <Label
                                Grid.Column="2"
                       TextColor="Black"
                       Text="{Binding jvref}"
                       LineBreakMode="TailTruncation"
                                 VerticalOptions="Center"
                                HorizontalOptions="Center"
                       FontAttributes="Italic"
                        />

                                    <Label
                      TextColor="Black"
                                Grid.Column="3"
                                 VerticalOptions="Center"
                                HorizontalOptions="Center"
                       Text="{Binding desc}"
                                        FontSize="12"
                       LineBreakMode="TailTruncation"
                       FontAttributes="Italic"
                       />

                                    <Label
                                Grid.Column="4"
                       TextColor="Black"
                       Text="{Binding jvdebit}"
                                        FontSize="12"
                       LineBreakMode="TailTruncation"
                                 VerticalOptions="Center"
                                HorizontalOptions="Center"
                       FontAttributes="Italic"
                       />

                                    <Label
                                Grid.Column="5"
                       TextColor="Black"
                       Text="{Binding jvcredit}"
                       LineBreakMode="TailTruncation"
                                 VerticalOptions="Center"
                                        FontSize="12"
                                HorizontalOptions="Center"
                       FontAttributes="Italic"
                       />

                                    <Label
                                Grid.Column="6"
                       TextColor="Black"
                       Text="{Binding balance}"
                       LineBreakMode="TailTruncation"
                                        FontSize="12"
                                 VerticalOptions="Center"
                                HorizontalOptions="Center"
                       FontAttributes="Italic"
                       />

                                </Grid>
                            </DataTemplate>
                        </CollectionView.ItemTemplate>
                        <CollectionView.FooterTemplate  >
                            <DataTemplate>
                            <Grid Padding="2" ColumnSpacing="1" RowSpacing="1" x:Name="gridfooter" >
                                <Grid.RowDefinitions>
                                    <RowDefinition Height="35" />

                                </Grid.RowDefinitions>
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="0.45*" />
                                    <ColumnDefinition Width="0.2*" />
                                    <ColumnDefinition Width="0.2*"/>
                                    <ColumnDefinition Width="0.5*" />
                                    <ColumnDefinition Width="0.35*" />
                                    <ColumnDefinition Width="0.35*" />
                                    <ColumnDefinition Width="0.35*" />
                                </Grid.ColumnDefinitions>

                                <Label Grid.Column="3"
                       Text="{Binding total}"
                       FontAttributes="Bold"
                               x:Name="total"
                                       FontSize="14"
                       LineBreakMode="TailTruncation"
                                   HorizontalOptions="Center"
                                   VerticalOptions="Center"
                                   TextColor="Black"/>

                                <Label Grid.Column="4"
                               x:Name="totaldebit"
                       Text="{Binding Totjvdebit}"
                       FontAttributes="Italic"
                                       FontSize="12"
                       LineBreakMode="TailTruncation"
                                   HorizontalOptions="Center"
                                   VerticalOptions="Center"
                                   TextColor="Black"/>
                                <Label Grid.Column="5"
                       Text="{Binding Totjvcredit}"
                       FontAttributes="Bold"
                                       FontSize="14"
                       LineBreakMode="TailTruncation"
                                   HorizontalOptions="Center"
                                   VerticalOptions="Center"
                                   TextColor="Black"/>
                                <Label Grid.Column="6"
                       Text="{Binding Totbalance}"
                       FontAttributes="Bold"
                                       FontSize="14"
                       LineBreakMode="TailTruncation"
                                   HorizontalOptions="Center"
                                   VerticalOptions="Center"
                                   TextColor="Black"/>

                            </Grid>
                            </DataTemplate>
                        </CollectionView.FooterTemplate>
                    </CollectionView>
                    
                    <StackLayout VerticalOptions="EndAndExpand"  HorizontalOptions="FillAndExpand" Orientation="Horizontal" BackgroundColor="#ffc40c">
                        <StackLayout Style="{StaticResource ButtonNavigationBarStackLayoutStyle}" x:Name="stckcol">
                            <Image Margin="0,10,0,10" x:Name="imgAdd" Style="{StaticResource ButtonNavigationBarImageStyle}" />
                            <Label Text="del" Style="{StaticResource ButtonNavigationBarLabelStyle}" x:Name="col_add_remove"></Label>
                        </StackLayout>
                        <StackLayout Style="{StaticResource ButtonNavigationBarStackLayoutStyle}" x:Name="stckfilter">
                            <Image Margin="0,10,0,10" x:Name="imgfilter" Style="{StaticResource ButtonNavigationBarImageStyle}" />
                            <Label Text="Filter" Style="{StaticResource ButtonNavigationBarLabelStyle}"></Label>
                        </StackLayout>
                        <StackLayout Style="{StaticResource ButtonNavigationBarStackLayoutStyle}" x:Name="stckshare">
                            <Image Margin="0,10,0,10" x:Name="imgshare" Style="{StaticResource ButtonNavigationBarImageStyle}" />
                            <Label Text="Share" Style="{StaticResource ButtonNavigationBarLabelStyle}"></Label>
                        </StackLayout>

                    </StackLayout>
                </StackLayout>
            </StackLayout>
            <ContentView x:Name="popupLoadingView" BackgroundColor="Transparent" Padding="10, 0" IsVisible="false"  AbsoluteLayout.LayoutBounds="0, 0, 1, 1" AbsoluteLayout.LayoutFlags="All">
                <StackLayout VerticalOptions="Center" HorizontalOptions="Center">
                    <StackLayout Orientation="Vertical" HeightRequest="150" WidthRequest="200" BackgroundColor="Transparent">

                        <ActivityIndicator x:Name="activityIndicator" Margin="0,50,0,0" VerticalOptions="Center" HorizontalOptions="Center" Color="Black" WidthRequest="40" HeightRequest="40" ></ActivityIndicator>
                    </StackLayout>
                </StackLayout>
            </ContentView>
        </AbsoluteLayout>
    </ContentPage.Content>
</ContentPage>

这是我的代码 xaml.cs

 public partial class account_details : ContentPage
    {
       
        List<accountdetails> listacc_collection = new List<accountdetails>();
        public string total = "";
        public account_details(string acc, string cur, string accname)
        {
           
            InitializeComponent();
            BindingContext = this;
            imgAdd.Source = ImageSource.FromResource("isc_alphaApp.remove_ic.png");
            imgfilter.Source = ImageSource.FromResource("isc_alphaApp.filter_ic.png");
            imgshare.Source = ImageSource.FromResource("isc_alphaApp.share_icon.png");
            loadData(acc,cur,accname);
}

  async private void loadData(string account, string curr,string acc_name )
        {
            acc_curlabel.Text = account + " - " + curr + " - " + acc_name;
            popupLoadingView.IsVisible = true;
            activityIndicator.IsRunning = true;
            HttpClient client = new HttpClient();
            string url = "http://192.168.43.99/siteisc/api/values";
            string uri = url + "/getaccountdetails";
            
            try
            {

                HttpResponseMessage response = await client.GetAsync(uri);

                if (response.IsSuccessStatusCode == true)
                {
                    string content = await response.Content.ReadAsStringAsync();
                    var listacc_details = JsonConvert.DeserializeObject<List<allaccountdetails>>(content);
                    var list_filtered = listacc_details.FindAll(x => x.JvAccount == account && x.CurrencyCode == curr);
                    decimal blnce_row = 0;
                    List<String> l = new List<String>();
                    for (int i = 0; i < list_filtered.Count; i++)
                    {
                        blnce_row = decimal.Parse(list_filtered[i].JvDebit.ToString()) - decimal.Parse(list_filtered[i].Jvcredit.ToString()) + blnce_row;
                        decimal rnd_blnce = Math.Round(blnce_row, 2);
                        l.Add(rnd_blnce.ToString());
                    }
                    l.ToArray();

                    for (int i = 0; i < list_filtered.Count; i++)
                    {
                        listacc_collection.Add(new accountdetails { desc = list_filtered[i].JvDescription, jvnbr = list_filtered[i].jvnbr.ToString(), jvcredit = list_filtered[i].Jvcredit.ToString(), jvdate = DateTime.Parse(list_filtered[i].JvDate).ToString(("dd-M-yyyy")), jvdebit = list_filtered[i].JvDebit.ToString(), jvref = list_filtered[i].jvref1, balance = l[i] });
                    }
                    var list_acc_footer = new List<footeraccount>();
                    list_acc_footer.Add(new footeraccount { total = "Total in" + " " + curr, Totjvdebit = getTotal_dbt(listacc_collection), Totjvcredit = getTotal_crdt(listacc_collection),Totbalance= getTotal_dbt(listacc_collection) - getTotal_crdt(listacc_collection) });
                    accountdetailslst.ItemsSource = listacc_collection;
                    total = "Total in" + " " + curr;
                    popupLoadingView.IsVisible = false;
                    activityIndicator.IsRunning = false;
                }
                else
                {
                    await DisplayAlert("Operation Failed", "Response Failed!", "Cancel");
                }

            }
            catch (System.Net.WebException exp)
            {
                await DisplayAlert("Connection Failed", "Please Check Your Internet Connection!", "Cancel");
            }
        }
}
}

我尝试做一些类似于 link https://www.c-sharpcorner.com/article/xamarin-forms-using-listview-headertemplate-and-footertemplate-to-display-data/ 中的代码的事情，但没有成功。这就是我所做的： footer.cs

 public class footer
    {
        public List<accountdetails> GetAll { get; private set; }

        public footer()
        {
            GetAll=new List<accountdetails> { new accountdetails { jvdate = "sksj", jvnbr = "idjd", desc = "kjsjs", balance = "ksjh", jvcredit = "4", jvdebit = "3", jvref = "jy" } };


        }
    }

AccountViewModel.cs:

 public class AccountViewModel
    {
        public string total = "";
        public List<accountdetails> items { get; private set; }
        public AccountViewModel()
        {
            var service = new footer();
            items = service.GetAll;
            total = service.GetAll.Count.ToString();
           

        }
    }
}

在 xaml.cs 我刚刚写了这个：

  public account_details(string acc, string cur, string accname)
        {
           
            InitializeComponent();
            BindingContext = new AccountViewModel();
}

但是没有用。我的页脚中没有任何内容。我应该怎么办？提前致谢

Answer 1

发帖人 (rana hd) 在对该问题的评论中说，使这些字段属性有效。

例如视图模型中的这是什么：

public string total = "";

需要改成这样：

public string total { get; set; } = "";

将 collectionview 页脚绑定到数据 xamarin.forms

bind collectionview footer to data xamarin.forms

footer

collectionview

xamarin.forms

android-databinding