xaml - Xamarin 表单 : How to fix Activity Indicator in Centre of Screen in Scrollview

Question

我有一个 ScrollView在 AbsoluteLayout ..
我需要修复 ActivityIndi​​cator 在屏幕中央的位置。
我尝试了以下代码。

<ScrollView>
    <AbsoluteLayout VerticalOptions="FillAndExpand"
                    HorizontalOptions="FillAndExpand">
        <StackLayout BackgroundColor="White"
                     Padding="50,20,50,20"
                     Spacing="5"
                     AbsoluteLayout.LayoutBounds="0,0,1,1"
                     AbsoluteLayout.LayoutFlags="All"> 
            // have set of elements..
        </StackLayout>
        <ActivityIndicator IsVisible="{Binding IsBusy}"
                           IsRunning="{Binding IsBusy}"
                           Color="Black"
                           AbsoluteLayout.LayoutBounds="0.5,0.5,0.1,0.1"
                           AbsoluteLayout.LayoutFlags="All"/>
    </AbsoluteLayout>
</ScrollView>

我发现结果在 ScrollView 的中心.

我尝试放置 ActivityIndicator外面ScrollView它只是将白屏作为输出。

如何固定 ActivityIndicator 的位置在屏幕中央？

Answer 1

正如@Vahid 所说，如果你想要 ActivityIndicator过ScrollView ，您需要将两者都放在 AbsoluteLayout 中，如下所示:

<AbsoluteLayout VerticalOptions="FillAndExpand"
                HorizontalOptions="FillAndExpand">
    <ScrollView AbsoluteLayout.LayoutBounds="0,0,1,1"
                AbsoluteLayout.LayoutFlags="All"
                VerticalOptions="FillAndExpand"
                HorizontalOptions="FillAndExpand">
        <StackLayout BackgroundColor="White"
                     Padding="50,20,50,20"
                     Spacing="5">
            // Your stuff goes here
        </StackLayout>
    </ScrollView>
    <AbsoluteLayout BackgroundColor="#22000000"
                    AbsoluteLayout.LayoutBounds="0.5,0.5,1,1"
                    AbsoluteLayout.LayoutFlags="All"
                    IsVisible="{Binding IsBusy}">
        <ActivityIndicator Color="Black"
                           AbsoluteLayout.LayoutBounds="0.5,0.5,0.1,0.1"
                           AbsoluteLayout.LayoutFlags="All"
                           IsVisible="True"
                           IsRunning="True"/>
    </AbsoluteLayout>
</AbsoluteLayout>

请注意，我添加了一个额外的 AbsoluteLayout这就像 ScrollView 上的“等待覆盖”只有 - 不是整个屏幕。