c# - Xamarin.Forms 上的混合固定元素和可滚动元素

Question

我刚刚开始使用 Xamarin.Forms 进行编程，恐怕我可能需要一些帮助。我对标准 XAML 相当得心应手，但 Xamarin.Forms 有局限性和含糊不清的小警告。

所以问题是:如何在同一个 View 中实现混合的固定元素和可滚动元素？比如，我希望下面的按钮固定在底部，然后是内容区域的其余部分，我希望可以滚动。

有办法吗？

-- 更新--

好的...

这是我的代码，顶部和底部部分正确呈现，而 ScrollView 区域根本不呈现......它完全是空白......？

<ContentPage.Content>
    <Grid BackgroundColor="{StaticResource BackgroundGray}">
        <Grid.RowDefinitions>
            <RowDefinition Height="96" />
            <RowDefinition Height="*" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>

        <StackLayout Grid.Row="0" HeightRequest="96" BackgroundColor="White" VerticalOptions="Center">
            <Image Source="biodatix.jpg" VerticalOptions="Center" HeightRequest="48" Margin="4,8,4,4" />
            <Label FontFamily="Arial" FontSize="20" TextColor="{StaticResource AppLightOrange}" HorizontalTextAlignment="Center">BioDatix</Label>
        </StackLayout>

        <ScrollView Grid.Row="1" VerticalOptions="FillAndExpand">

            <Entry x:Name="Username" Placeholder="Email Address" Text="{Binding User.Email}" FontSize="Small" />
            <Label x:Name="reqemail" Text="Please enter an email address" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <Entry x:Name="RetypeUsername" Placeholder="Retype Email Address" FontSize="Small" />
            <Label x:Name="reqemailverify" Text="Please confirm your email address" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <Entry IsPassword="True" Placeholder="Password" x:Name="Password" Text="{Binding User.Password}" FontSize="Small" />
            <Label x:Name="reqpass" Text="Please enter a password" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <Entry x:Name="FirstName" Placeholder="First Name" Text="{Binding User.FirstName}" FontSize="Small" />
            <Label x:Name="reqfirstname" Text="Please enter your first name" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <Entry x:Name="LastName" Placeholder="Last Name" Text="{Binding User.LastName}" FontSize="Small" />
            <Label x:Name="reqlastname" Text="Please enter your last name" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <StackLayout Orientation="Horizontal" Margin="4">
                <Label x:Name="lblUseMetric" Margin="2">Use Metric System</Label>
                <Switch x:Name="UseMetric" IsToggled="{Binding User.Metric}"></Switch>
            </StackLayout>


            <Entry x:Name="UserHeight" Placeholder="Height" Text="{Binding User.Height}" FontSize="Small" />
            <Label x:Name="reqheight" Text="Please enter your height" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <Entry x:Name="UserWeight" Placeholder="Weight" Text="{Binding User.Weight}" FontSize="Small" />
            <Label x:Name="reqweight" Text="Please enter your weight" IsVisible="False" FontSize="Micro" TextColor="Red"/>


            <StackLayout Orientation="Horizontal" Margin="4">
                <Label x:Name="lblWearSide" Margin="2">Wears Right</Label>
                <Switch x:Name="WearSide" IsToggled="{Binding User.WearSide}"></Switch>
            </StackLayout>


            <Label x:Name="lblError" Text="" IsVisible="False" FontSize="Default" TextColor="Red"/>


        </ScrollView>

        <Button x:Name="RegisterBtn" Clicked="RegisterBtn_Clicked" WidthRequest="200" HorizontalOptions="Center" BackgroundColor="{StaticResource AppGreen}" Grid.Row="2" Text="Sign In" Margin="4" />

        <Button x:Name="CancelBtn" Clicked="CancelBtn_Clicked"  WidthRequest="200" HorizontalOptions="Center" BackgroundColor="{StaticResource AppGreen}" Grid.Row="3" Text="Help Signing In" Margin="4" />
    </Grid>

</ContentPage.Content>

Answer 1

Yes, it's possible using Layouts and ScrollViews.

例如，如果你想让你的按钮固定在底部，你可以使用follow organization

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
                 xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                 xmlns:local="clr-namespace:Sample"
                 x:Class="Sample.MainPage">
        <Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="*"/>
                <RowDefinition Height="Auto"/>
            </Grid.RowDefinitions>

            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition Width="*"/>
            </Grid.ColumnDefinitions>


            <ScrollView Grid.ColumnSpan="2">

                <!-- Put all the content here -->

            </ScrollView>

            <Button Text="Cancel" Grid.Row="1" Grid.Column="0" BackgroundColor="Red"/>
            <Button Text="Ok" Grid.Row="1" Grid.Column="1" BackgroundColor="Green"/>

        </Grid>
    </ContentPage>

Remeber that ScrollView can only contain one children, so you need to wrap your content inside a layout.

针对您的具体情况:

<?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="Sample.MixedPage">
    <Grid BackgroundColor="{StaticResource BackgroundGray}">
        <Grid.RowDefinitions>
            <RowDefinition Height="96" />
            <RowDefinition Height="*" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>

        <StackLayout Grid.Row="0" HeightRequest="96" BackgroundColor="White" VerticalOptions="Center">
            <Image Source="biodatix.jpg" VerticalOptions="Center" HeightRequest="48" Margin="4,8,4,4" />
            <Label FontFamily="Arial" FontSize="20" TextColor="{StaticResource AppLightOrange}" HorizontalTextAlignment="Center">BioDatix</Label>
        </StackLayout>

        <ScrollView Grid.Row="1" VerticalOptions="FillAndExpand">
            <StackLayout>
            <Entry x:Name="Username" Placeholder="Email Address" Text="{Binding User.Email}" FontSize="Small" />
            <Label x:Name="reqemail" Text="Please enter an email address" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <Entry x:Name="RetypeUsername" Placeholder="Retype Email Address" FontSize="Small" />
            <Label x:Name="reqemailverify" Text="Please confirm your email address" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <Entry IsPassword="True" Placeholder="Password" x:Name="Password" Text="{Binding User.Password}" FontSize="Small" />
            <Label x:Name="reqpass" Text="Please enter a password" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <Entry x:Name="FirstName" Placeholder="First Name" Text="{Binding User.FirstName}" FontSize="Small" />
            <Label x:Name="reqfirstname" Text="Please enter your first name" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <Entry x:Name="LastName" Placeholder="Last Name" Text="{Binding User.LastName}" FontSize="Small" />
            <Label x:Name="reqlastname" Text="Please enter your last name" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <StackLayout Orientation="Horizontal" Margin="4">
                <Label x:Name="lblUseMetric" Margin="2">Use Metric System</Label>
                <Switch x:Name="UseMetric" IsToggled="{Binding User.Metric}"></Switch>
            </StackLayout>


            <Entry x:Name="UserHeight" Placeholder="Height" Text="{Binding User.Height}" FontSize="Small" />
            <Label x:Name="reqheight" Text="Please enter your height" IsVisible="False" FontSize="Micro" TextColor="Red"/>

            <Entry x:Name="UserWeight" Placeholder="Weight" Text="{Binding User.Weight}" FontSize="Small" />
            <Label x:Name="reqweight" Text="Please enter your weight" IsVisible="False" FontSize="Micro" TextColor="Red"/>


            <StackLayout Orientation="Horizontal" Margin="4">
                <Label x:Name="lblWearSide" Margin="2">Wears Right</Label>
                <Switch x:Name="WearSide" IsToggled="{Binding User.WearSide}"></Switch>
            </StackLayout>


            <Label x:Name="lblError" Text="" IsVisible="False" FontSize="Default" TextColor="Red"/>

            </StackLayout>
        </ScrollView>

        <Button x:Name="RegisterBtn" Clicked="RegisterBtn_Clicked" WidthRequest="200" HorizontalOptions="Center" BackgroundColor="{StaticResource AppGreen}" Grid.Row="2" Text="Sign In" Margin="4" />

        <Button x:Name="CancelBtn" Clicked="CancelBtn_Clicked"  WidthRequest="200" HorizontalOptions="Center" BackgroundColor="{StaticResource AppGreen}" Grid.Row="3" Text="Help Signing In" Margin="4" />
    </Grid>
</ContentPage>

结果是: