xamarin - 如何使用 Xamarin 表单中的 TabbedPage 在导航栏中添加徽章计数？

Question

我想在带有徽章计数的购物车图标中添加导航栏。
我使用工具栏项在导航栏中添加了购物车图标。并使用插件创建了徽章计数圆 View 。如果我要留出余量来将该徽章图标设置为工具栏项目，则它会隐藏在选项卡式页面后面。

它没有显示在购物车图标上。

请帮我解决这个问题。



根据上图，我想用标签页设置徽章计数。

下面是我的 XAML代码。

<?xml version="1.0" encoding="utf-8" ?>
<TabbedPage  xmlns="http://xamarin.com/schemas/2014/forms"
         xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
          xmlns:lang="clr-namespace:Conekto"
         xmlns:controls="clr-namespace:Conekto.Controls;"
         x:Class="ProjectName.Pages.SalePage">
<TabbedPage.Children>
    <ContentPage Title="{lang:Translate PRODUCTLIST}">
        <Grid Margin="10,10,10,0" BackgroundColor="White">
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="50" />
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="*" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>
                <Button Grid.Row="0" Grid.Column="0" Text="charge 15,123" Style="{StaticResource primaryButton}" />
                <SearchBar x:Name="txtSearch" Grid.Row="1" Grid.Column="0" TextChanged="MySearchBarOnTextChanged" Placeholder="{lang:Translate Search}" SearchCommand="{Binding SearchCommand, Mode=TwoWay}" CancelButtonColor="Blue" Text="{Binding SearchText, Mode=TwoWay}" Style="{StaticResource labelgreycolour}" WidthRequest="50" HorizontalOptions="FillAndExpand"
                    VerticalOptions="FillAndExpand" />
                <StackLayout Grid.Row="2" Grid.Column="0"  VerticalOptions="StartAndExpand" HorizontalOptions="FillAndExpand">
                    <ListView x:Name="listView" ItemsSource="{Binding ProductList}" HasUnevenRows="True" IsPullToRefreshEnabled="true" RefreshCommand="{Binding RefreshCommand}" IsRefreshing="{Binding IsRefreshing}" ItemAppearing="listView_ItemAppearing" ItemSelected="listView_ItemSelected" SelectedItem="{Binding listView_ItemSelected, Mode=TwoWay}" BackgroundColor="White" HorizontalOptions="FillAndExpand">
                        <ListView.ItemTemplate>
                            <DataTemplate>
                                <ViewCell>
                                    <Grid Margin="0,5,0,5">
                                        <Grid.RowDefinitions>
                                            <RowDefinition Height="Auto" />
                                            <RowDefinition Height="Auto" />
                                        </Grid.RowDefinitions>
                                        <Grid.ColumnDefinitions>
                                            <ColumnDefinition Width="10*" />
                                            <ColumnDefinition Width="50*" />
                                            <ColumnDefinition Width="40*" />
                                        </Grid.ColumnDefinitions>
                                        <Image Source="add" Grid.Row="0" Grid.Column="0" Grid.RowSpan="2" Aspect="AspectFit" HeightRequest="30" WidthRequest="30" VerticalOptions="CenterAndExpand"  HorizontalOptions="CenterAndExpand">
                                            <Image.GestureRecognizers>
                                                <TapGestureRecognizer Command="{Binding BindingContext.AddProductCommand, Source={x:Reference listView}}" CommandParameter="{Binding .}" NumberOfTapsRequired="1" />
                                            </Image.GestureRecognizers>
                                        </Image>
                                        <Label Grid.Row="0" Grid.Column="1" VerticalOptions="CenterAndExpand" VerticalTextAlignment="End"  Text="{Binding ProductName,Mode=TwoWay}" Style="{StaticResource entrylogin}" />
                                        <Label Grid.Row="1" Grid.Column="1" VerticalOptions="CenterAndExpand" VerticalTextAlignment="End" Text="{Binding Cost,Mode=TwoWay,StringFormat='XOF {0}'}" Style="{StaticResource listViewsublabel}" />
                                    </Grid>                                     
                                </ViewCell>
                            </DataTemplate>
                        </ListView.ItemTemplate>
                    </ListView>
                </StackLayout>
            </Grid>                
            <controls:FloatingActionButton Margin="0,0,20,20"  Grid.Row="0" x:Name="FABCart" HorizontalOptions="End" VerticalOptions="End" WidthRequest="60" HeightRequest="60"  Image="cart" ButtonColor="#09999A" Clicked="FabCart_Clicked" />
            <controls:BadgeView Margin="0,0,32,52"  Grid.Row="0" Text="{Binding TotalCartItem, Mode=TwoWay}" BadgeColor="White" HorizontalOptions="End" VerticalOptions="End" />
        </Grid>
    </ContentPage>
    <ContentPage Title="{lang:Translate KEYPAD}">
        <ContentPage.BackgroundColor>
            <OnPlatform x:TypeArguments="Color">
                <OnPlatform.Platforms>
                    <On Platform="iOS" Value="Black" />
                    <On Platform="Android" Value="#eee" />
                </OnPlatform.Platforms>
            </OnPlatform>
        </ContentPage.BackgroundColor>
        <Grid x:Name="controlGrid" Margin="0,0,0,0" Padding="0,0,0,0" VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand">
            <Grid.ColumnSpacing>
                <OnPlatform x:TypeArguments="x:Double">
                    <OnPlatform.Platforms>
                        <On Platform="iOS" Value="1" />
                        <On Platform="Android" Value="0" />
                    </OnPlatform.Platforms>
                </OnPlatform>
            </Grid.ColumnSpacing>
            <Grid.RowSpacing>
                <OnPlatform x:TypeArguments="x:Double">
                    <OnPlatform.Platforms>
                        <On Platform="iOS" Value="1" />
                        <On Platform="Android" Value="0" />
                    </OnPlatform.Platforms>
                </OnPlatform>
            </Grid.RowSpacing>
            <Grid.RowDefinitions>
                <RowDefinition Height="74" />
                <RowDefinition Height="80" />
                <RowDefinition Height="*" />
                <RowDefinition Height="*" />
                <RowDefinition Height="*" />
                <RowDefinition Height="*" />
            </Grid.RowDefinitions>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*" />
                <ColumnDefinition Width="*" />
                <ColumnDefinition Width="*" />
            </Grid.ColumnDefinitions>
            <Button Text="charge 15,123" Margin="12,12,12,12" Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3" Style="{StaticResource primaryButton}" />
            <Label Text="Add note" FontSize="10" Grid.Column="0" Grid.Row="1" HorizontalTextAlignment="Center" VerticalTextAlignment="End" TextColor="Black" />
            <Label x:Name="lblVal" Margin="0,0,16,0" Grid.Row="1" Grid.Column="1" HorizontalTextAlignment="End" VerticalTextAlignment="Center" TextColor="Black" FontSize="30" Grid.ColumnSpan="2" VerticalOptions="End" />
            <Button Clicked="Button_Clicked" Text ="7" Grid.Row="2" Grid.Column="0" Style="{StaticResource plainButton}" />
            <Button Clicked="Button_Clicked" Text = "8" Grid.Row="2" Grid.Column="1" Style="{StaticResource plainButton}" />
            <Button Clicked="Button_Clicked" Text = "9" Grid.Row="2" Grid.Column="2" Style="{StaticResource plainButton}" />
            <Button Clicked="Button_Clicked" Text = "4" Grid.Row="3" Grid.Column="0" Style="{StaticResource plainButton}" />
            <Button Clicked="Button_Clicked" Text = "5" Grid.Row="3" Grid.Column="1" Style="{StaticResource plainButton}" />
            <Button Clicked="Button_Clicked" Text = "6" Grid.Row="3" Grid.Column="2" Style="{StaticResource plainButton}" />
            <Button Clicked="Button_Clicked" Text = "1" Grid.Row="4" Grid.Column="0" Style="{StaticResource plainButton}" />
            <Button Clicked="Button_Clicked" Text = "2" Grid.Row="4" Grid.Column="1" Style="{StaticResource plainButton}" />
            <Button Clicked="Button_Clicked" Text = "3" Grid.Row="4" Grid.Column="2" Style="{StaticResource plainButton}" />
            <Button Clicked="ButtonClear_Clicked" Text = "C" Grid.Row="5" Grid.Column="0" Style="{StaticResource plainButton}" />
            <Button Clicked="Button_Clicked" Text = "0" Grid.Row="5" Grid.Column="1" Style="{StaticResource plainButton}" />
            <Button Clicked="Button_Clicked" Text = "+" Grid.Row="5" Grid.Column="2" Style="{StaticResource plainButton}" />
        </Grid>
    </ContentPage>
    <ContentPage Title="{lang:Translate SCAN}">
    </ContentPage>
</TabbedPage.Children>

在 .cs 页面代码中，我在工具栏项中添加购物车图标。

  ToolbarItems.Add(new ToolbarItem("Add Product", "floating", async () =>
            {
                //var page = new ContentPage();
                //var result = await page.DisplayAlert("Title", "Message", "Accept", "Cancel");
                await Navigation.PushAsync(new CreateProductPage() { Title = Helper.GetResxNameByValue("CreateProduct") });

                //Debug.WriteLine("success: {0}", result);
            }));

根据设计，我添加了购物车按钮作为 float 按钮。请不要考虑。

Answer 1

要在工具栏项上添加徽章，您可以使用 NavigationPage.SetHasNavigationBar(this, false); 隐藏默认工具栏。然后您可以创建自己的工具栏，带有带有徽章计数器和汉堡包的按钮来显示和隐藏侧边菜单。

在点击汉堡按钮的页面上:

private void Button_Clicked(object sender, System.EventArgs e)
        {
            MessagingCenter.Send(this, "presnt");           
        }

在 MasterDetail 页面上:

MessagingCenter.Subscribe<YourPage>(this, "presnt", (sender) =>
            {
                IsPresented = true;
            });

另外，在制作之前 IsPresented=true ，检查滑动菜单没有准备好呈现。

您可以查看 https://github.com/LeslieCorrea/Xamarin-Forms-Shopping-Cart此链接了解更多信息。但是通过在android中使用这种方法可能会使导航栏出现在选项卡下方，因此您可能需要使用按钮创建选项卡。