为框架设置每个角半径很热门？可以一个一个地设置，但是我一个一个地设置，2四舍五入2正常。
【问题讨论】：
Frame 小部件不允许更改单个角，您当然可以通过每个平台的自定义渲染器来执行此操作。即在 iOS 上，您可以向控件添加遮罩层，stackoverflow.com/a/43877570/4984832
标签： c# xamarin xamarin.forms
没有破解，有一个非常简单的解决方案：
使用 nuget 包Xamarin.Forms.PancakeView。
如何使用？
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:yummy="clr-namespace:Xamarin.Forms.PancakeView;assembly=Xamarin.Forms.PancakeView">
...
</ContentPage>
<yummy:PancakeView BackgroundColor="#bc91d7" CornerRadius="60,0,0,60" IsClippedToBounds="true" HorizontalOptions="FillAndExpand" HeightRequest="150">
<Image Source="unicorn.png" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" Aspect="AspectFill" />
</yummy:PancakeView>
【讨论】：
对 xaml 的一次非常骇人听闻的尝试，您仍然可以注意到边界上的伪影，但为了快速开始，为什么不...
<Grid>
<Frame Margin="0,0,0,20" HasShadow="False" BorderColor="Transparent" CornerRadius="12" HorizontalOptions="Fill" VerticalOptions="Fill" BackgroundColor="Gray"/>
<Frame Margin="1,1,1,20" HasShadow="False" BorderColor="Transparent" CornerRadius="11" HorizontalOptions="Fill" VerticalOptions="Fill" BackgroundColor="White"/>
<Frame Margin="0,20,0,0" VerticalOptions="Fill" HasShadow="False" BorderColor="Transparent" CornerRadius="2" HorizontalOptions="Fill" BackgroundColor="Gray" />
<Frame Margin="1,20,1,1" VerticalOptions="Fill" HasShadow="False" BorderColor="Transparent" CornerRadius="2" HorizontalOptions="Fill" BackgroundColor="White" />
<BoxView Margin="1.75,15,1.75,15" HorizontalOptions="Fill" VerticalOptions="Fill" BackgroundColor="White" HeightRequest="19" StyleId="hide background"/>
<ContentView Margin="8" x:Name="MainContainer">
<StackLayout >
<Label TextColor="DimGray" Text="This is your main container"/>
<Label TextColor="DimGray" Text="Put stuff here"/>
</StackLayout>
</ContentView>
</Grid>
【讨论】：
您需要在每个平台上创建自定义渲染器。我不知道你是否可以单独控制半径，但你可以控制拐角是否符合半径。
首先，您需要在共享项目中使用一个自定义类来充当您的自定义控件...
using System;
using Xamarin.Forms;
namespace MyApp.Controls
{
public class CustomFrame : Frame
{
// ---------------------------------------------------------------------------------------------------------------
public static readonly BindableProperty CornerRadiusTopLeftProperty = BindableProperty.Create(
propertyName: "CornerRadiusTopLeft",
returnType: typeof(bool),
declaringType: typeof(CustomFrame),
defaultValue: true,
defaultBindingMode: BindingMode.TwoWay
);
public bool CornerRadiusTopLeft
{
get { return (bool)GetValue(CornerRadiusTopLeftProperty); }
set { base.SetValue(CornerRadiusTopLeftProperty, value); }
}
// ---------------------------------------------------------------------------------------------------------------
public static readonly BindableProperty CornerRadiusTopRightProperty = BindableProperty.Create(
propertyName: "CornerRadiusTopRight",
returnType: typeof(bool),
declaringType: typeof(CustomFrame),
defaultValue: true,
defaultBindingMode: BindingMode.TwoWay
);
public bool CornerRadiusTopRight
{
get { return (bool)GetValue(CornerRadiusTopRightProperty); }
set { base.SetValue(CornerRadiusTopRightProperty, value); }
}
// ---------------------------------------------------------------------------------------------------------------
public static readonly BindableProperty CornerRadiusBottomLeftProperty = BindableProperty.Create(
propertyName: "CornerRadiusBottomLeft",
returnType: typeof(bool),
declaringType: typeof(CustomFrame),
defaultValue: true,
defaultBindingMode: BindingMode.TwoWay
);
public bool CornerRadiusBottomLeft
{
get { return (bool)GetValue(CornerRadiusBottomLeftProperty); }
set { base.SetValue(CornerRadiusBottomLeftProperty, value); }
}
// ---------------------------------------------------------------------------------------------------------------
public static readonly BindableProperty CornerRadiusBottomRightProperty = BindableProperty.Create(
propertyName: "CornerRadiusBottomRight",
returnType: typeof(bool),
declaringType: typeof(CustomFrame),
defaultValue: true,
defaultBindingMode: BindingMode.TwoWay
);
public bool CornerRadiusBottomRight
{
get { return (bool)GetValue(CornerRadiusBottomRightProperty); }
set { base.SetValue(CornerRadiusBottomRightProperty, value); }
}
}
}
然后您需要在每个平台上创建渲染器。我还没有完成 Android 端，但这是你需要的 iOS ...
using System;
using CoreAnimation;
using MyApp.iOS.CustomRenderers;
using Foundation;
using MyApp.Controls;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
[assembly: ExportRenderer(typeof(CustomFrame), typeof(CustomFrameRenderer))]
namespace MyApp.iOS.CustomRenderers
{
public class CustomFrameRenderer : FrameRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<Frame> e)
{
base.OnElementChanged(e);
if (Element != null)
{
var element = Element as CustomFrame;
int result = 0;
if (element.CornerRadiusTopLeft)
result += (int)CACornerMask.MinXMinYCorner;
if (element.CornerRadiusTopRight)
result += (int)CACornerMask.MaxXMinYCorner;
if (element.CornerRadiusBottomLeft)
result += (int)CACornerMask.MinXMaxYCorner;
if (element.CornerRadiusBottomRight)
result += (int)CACornerMask.MaxXMaxYCorner;
Layer.MaskedCorners = (CACornerMask)result;
};
}
}
}
然后，您可以在 XAML 文件中将其用作自定义控件。
将命名空间添加到您的页面...
xmlns:customControls="clr-namespace:MyApp.Controls"
...然后添加您的自定义框架...
<customControls:CustomFrame BackgroundColor="White" CornerRadius="10" HasShadow="false"
CornerRadiusBottomLeft="false" CornerRadiusBottomRight="false" VerticalOptions="Start" HorizontalOptions="FillAndExpand" Padding="15">
<!-- Add your other elements here -->
</customControls:CustomFrame>
希望对你有所帮助。祝 Android 渲染器好运，我相信这并不难，只是还没开始。
【讨论】：
使用 Xamarin.Forms.PancakeView。
<yummy:PancakeView BackgroundColor="#2DA6EA" WidthRequest="300" HorizontalOptions="Start" CornerRadius="0,30,0,30">
<StackLayout>
<Label TextColor="White" Margin="10,0,0,0" FontSize="15" Text="Welcome"/>
<Label TextColor="White" Margin="10,0,0,0" FontSize="20" Text="Dolapo"/>
</StackLayout>
</yummy:PancakeView>
【讨论】：