这是我的 XAML
代码,我试图将一个 ActivityIndicator
放在其他 View 之上,但它根本没有显示,为什么?
<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" BackgroundImage="background_nonedit.png" Title="Citizen Reporter" x:Class="BBSTV.CitizenReporter">
<ScrollView>
<RelativeLayout VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand">
<StackLayout VerticalOptions="Center" HorizontalOptions="Fill" Padding="10" RelativeLayout.XConstraint="{ConstraintExpression Type=Constant, Constant=0}" RelativeLayout.YConstraint="{ConstraintExpression Type=Constant, Constant=0}">
<Grid x:Name="SegmentGrid" RowSpacing="10" ColumnSpacing="10">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
</Grid>
<Image x:Name="citizenImage" WidthRequest="400" HeightRequest="220" />
<Label VerticalOptions="Center" HorizontalOptions="Center" Margin="8" x:Name="attachment_label" />
<Entry Placeholder="News Title" Margin="8" VerticalOptions="Center" HeightRequest="40" />
<Entry Placeholder="News Details" Margin="8" VerticalOptions="Center" HeightRequest="90" />
<Button Text="CHOOSE PHOTO" Margin="8" Clicked="onChoosePhoto" TextColor="White" BackgroundColor="#4D7EE1" />
<Button Text="TAKE PHOTO" Margin="8" Clicked="onTakePhoto" TextColor="White" BackgroundColor="#4D7EE1" />
<Button Text="CHOOSE VIDEO" Margin="8" Clicked="onChooseVideo" TextColor="White" BackgroundColor="#4D7EE1" />
<Button Text="TAKE VIDEO" Margin="8" Clicked="onTakeVideo" TextColor="White" BackgroundColor="#4D7EE1" />
<Button Text="UPLOAD REPORT" Margin="9" Clicked="UploadFile_Clicked" TextColor="White" BackgroundColor="#F399FC " />
</StackLayout>
<ActivityIndicator x:Name="activity_i_citizenReport" Color="Black"
VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand"
/>
</RelativeLayout>
</ScrollView>
</ContentPage>
最佳答案
关于c# - 为什么事件指示器不显示?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/44517496/