问题描述
我正在构建一个应用程序，并且当我使用模拟器时调试工作正常，并且一切看起来都是我想要的。 因为我使用的是条形码扫描仪，所以我开始在我自己的 android 设备上进行调试，但随后我在其中一个页面中的大部分 UI 消失了。 （见图片）
我在谷歌时找不到任何类似的问题（尽管这可能是我的谷歌技能不佳）。 Here is on my device when its all vanished
Here is what it is suppose to look like
<?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="TergeoAppUI.Views.RegisterInventoryPage"
xmlns:vm="clr-namespace:TergeoAppUI.viewmodels"
xmlns:ZXing="clr-namespace:ZXing.Net.Mobile.Forms;assembly=ZXing.Net.Mobile.Forms" xmlns:model="clr-namespace:Tergeo.Models;assembly=Tergeo.Models"
x:DataType="vm:RegisterInventoryviewmodel"
Title="{Binding Title}">
<StackLayout>
<Grid Padding="0,5,0" ColumnSpacing="2">
<Grid.RowDeFinitions>
<RowDeFinition Height="Auto"/>
<RowDeFinition Height="*"/>
</Grid.RowDeFinitions>
<Grid.ColumnDeFinitions>
<ColumnDeFinition Width="Auto"/>
<ColumnDeFinition Width="*"/>
</Grid.ColumnDeFinitions>
<Button
ImageSource="barcode.png"
Text="Scanna"
BackgroundColor="#AAC0AA"
BorderColor="Black"
BorderWidth="3"
HeightRequest="200"
Grid.Row="1"
Grid.Column="2"
Grid.RowSpan="1"
Margin="70,10,10"
Command="{Binding GoToScanCommand}"
/>
<Entry
Grid.Row="1"
Grid.ColumnSpan="3"
Margin="20,30,160,5"
Placeholder="EAN,PLU..."
VerticalOptions="FillAndExpand"
Completed="{Binding OnEanEntryCompletionCommand}"
Text="{Binding Ean}"
Keyboard="Numeric"
/>
</Grid>
<Label Margin="30,2" FontSize="Medium" Text="{Binding ArticleName}"/>
<StackLayout HeightRequest="200">
<Grid Padding="2" VerticalOptions="Fill" >
<Grid.RowDeFinitions>
<RowDeFinition Height="Auto"/>
<RowDeFinition Height="*"/>
</Grid.RowDeFinitions>
<Grid.ColumnDeFinitions>
<ColumnDeFinition Width="Auto"/>
<ColumnDeFinition Width="*"/>
</Grid.ColumnDeFinitions>
<Label
Grid.Row="1"
Margin="30,2"
FontSize="Medium"
Text="{Binding RetailPrice,StringFormat='Utpris: {0:N}'}"/>
<Entry
Placeholder="Antal"
Grid.Row="2"
Grid.ColumnSpan="2"
Grid.Column='0'
Margin="20,20,0"
FontSize="Medium"
Text="{Binding Quantity,StringFormat='Antal: {0:N}'}"/>
<Entry
Grid.ColumnSpan="2"
Margin="0,0"
Placeholder="Låda"
Grid.Row="2"
Grid.Column="2"
FontSize="Medium"
Text="{Binding Box,StringFormat='Låda: {0:S}'}"
Completed="{Binding OnRegistrationCompletedCommand}"/>
</Grid>
</StackLayout>
<!-- List with all the inventoryregistration for this specific list -->
<ListView
BackgroundColor="White"
ItemsSource="{Binding InventoryList}"
HasUnevenRows="True"
SelectionMode="None"
>
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Grid Padding="1" ColumnSpacing="1">
<Grid.RowDeFinitions>
<RowDeFinition Height="Auto"/>
<RowDeFinition Height="*"/>
</Grid.RowDeFinitions>
<Grid.ColumnDeFinitions>
<ColumnDeFinition Width="Auto"/>
<ColumnDeFinition Width="*"/>
</Grid.ColumnDeFinitions>
<!-- ArticleName -->
<StackLayout
Padding="10,0"
x:DataType="model:InventoryInfoModel"
Grid.Column="0"
Grid.Row="0">
<Label
TextColor="Black"
FontFamily="PTC55F.ttf#ptc55f"
Text="{Binding ArticleName}"
FontSize="Small"/>
</StackLayout>
<!-- Article supplier -->
<StackLayout
Padding="10,0"
x:DataType="model:InventoryInfoModel"
Grid.Column="1"
Grid.Row="0"
Grid.ColumnSpan="2">
<Label
TextColor="Black"
FontFamily="PTC55F.ttf#ptc55f"
Text="{Binding supplier}"
FontSize="Small"/>
</StackLayout>
<!-- Article Ean -->
<StackLayout
Padding="10,0"
x:DataType="model:InventoryInfoModel"
Grid.Column="0"
Grid.Row="1">
<Label
FontFamily="PTC55F.ttf#ptc55f"
Margin="0,5"
Text="{Binding Ean}"
FontSize="Small"/>
</StackLayout>
<StackLayout
Padding="10,5"
Text="{Binding Plu}"
FontSize="Small"/>
</StackLayout>
<StackLayout
Padding="10,0"
x:DataType="model:InventoryInfoModel"
Grid.Column="1"
Grid.Row="1"
Grid.ColumnSpan="2">
<Label
FontFamily="PTC55F.ttf#ptc55f"
Margin="0,5"
Text="{Binding Quantity,StringFormat='Antal: {0:N}'}"
FontSize="Small"/>
</StackLayout>
<StackLayout
Padding="10,0"
x:DataType="model:InventoryInfoModel"
Grid.Column="4"
Grid.Row="0"
Grid.ColumnSpan="2">
<Label
FontFamily="PTC55F.ttf#ptc55f"
Margin="0,5"
Text="{Binding Box,StringFormat='Låda: {0:S}'}"
FontSize="Small"/>
</StackLayout>
<StackLayout
Padding="10,0"
x:DataType="model:InventoryInfoModel"
Grid.Column="4"
Grid.Row="1"
Grid.ColumnSpan="2">
<Label
FontFamily="PTC55F.ttf#ptc55f"
Margin="0,5"
Text="{Binding StorageName,StringFormat='Hyllplats: {0:S}'}"
FontSize="Small"/>
</StackLayout>
</Grid>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
</ContentPage>
解决方法
容易修复，当您在 android 设备上调试时，显然所有文本的默认颜色都是白色，所以我所做的只是将 PlaceholderColor 或 textcolor 添加到所有标签/条目。