xamarin - 是否可以为 Xamarin 框架提供不同的边框颜色？

Question

这是我的 XAML:

<Frame CornerRadius="1" HasShadow="false" Margin="10" 
   BackgroundColor="White" BorderColor="Silver" Padding="0" >

我在 iOS 上的谷歌翻译上看到，他们使用类似框架的东西来包围设置中的不同行。然而，它们的顶部和底部边框颜色不同。

有谁知道是否有办法用框架来做到这一点？

Answer 1

您可以使用像这样的组件来实现这一点

BorderEntryComponent.xaml

<?xml version="1.0" encoding="UTF-8"?>
<StackLayout
    xmlns="http://xamarin.com/schemas/2014/forms"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    x:Class="X.Y.Z.BorderEntryComponent"

    Spacing="0">
    <BoxView
        x:Name="TopBorder"
        HeightRequest="2"
        HorizontalOptions="FillAndExpand"
        VerticalOptions="EndAndExpand" />
    <Entry x:Name="Entry" />
    <BoxView
        x:Name="BottomBorder"
        HeightRequest="2"
        HorizontalOptions="FillAndExpand"
        VerticalOptions="EndAndExpand" />
</StackLayout>

并且，在您的 BorderEntryComponent.xaml.cs

using System;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
using Xamarin.Forms;

namespace X.Y.Z
{
    public partial class BorderEntryComponent : StackLayout
    {    
        public static readonly BindableProperty TopColorProperty =
            BindableProperty.Create(nameof(TopColor), typeof(Color), typeof(BorderEntryComponent), default(Color), BindingMode.OneWay);

        public static readonly BindableProperty BottomColorProperty =
            BindableProperty.Create(nameof(BottomColor), typeof(Color), typeof(BorderEntryComponent), default(Color), BindingMode.OneWay);

        public UnderlineEntryComponent()
        {
            InitializeComponent();
        }

        protected override void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            base.OnPropertyChanged(propertyName);

            if (propertyName == TopColorProperty.PropertyName)
            {
                this.TopBorder.Color = TopColor;
            }
            else if (propertyName == BottomColorProperty.PropertyName)
            {
                this.BottomBorder.Color = BottomColor;
            }
        }

        public Color TopColor
        {
            get => (Color)GetValue(TopColorProperty);
            set => SetValue(TopColorProperty, value);
        }

        public Color BottomColor
        {
            get => (Color)GetValue(BottomColorProperty);
            set => SetValue(BottomColorProperty, value);
        }
    }
}

然后，您只需在 .xaml 上执行此操作即可

<components:UnderlineEntryComponent
                    TopColor = "Blue"
                    BottomColor = "Black" />

您可以阅读有关可绑定(bind)属性的更多信息 here