Xamarin.Forms x:共享 [英] Xamarin.Forms x:Shared

问题描述

我当前正在使用的Xamarin.Forms应用程序有问题.我创建的资源正在多个控件中使用，这些控件使用同一对象将其呈现到屏幕上.我以为使用x:Shared="False"属性(按照 https://docs.microsoft.com/zh-cn/dotnet/framework/xaml-services/x-shared-attribute )即可解决.它不是:(有什么想法可以在.xaml中创建同一对象而不必定义多个资源吗?

I have an issue with a Xamarin.Forms application I am currently working on. The resource I have created is being used within multiple controls, the controls are using the same object to render out onto the screen. I thought using the x:Shared="False" attribute (as per https://docs.microsoft.com/en-us/dotnet/framework/xaml-services/x-shared-attribute) would get around this. It does not :( Any ideas how to create the same object in .xaml without having to define multiple resources?

<Grid.Resources>
 <ResourceDictionary>
   <SharedShapes:Circle x:Shared="False" x:Key="SpecCircle" Color="{StaticResource AccentColor}"/>
 </ResourceDictionary>
</Grid.Resources>

<SharedControls:ImageButton Grid.Row="0" Grid.Column="0" Shape="{StaticResource SpecCircle}"...
<SharedControls:ImageButton Grid.Row="1" Grid.Column="0" Shape="{StaticResource SpecCircle}"...
.
.
.

非常感谢！

推荐答案

您提到的链接主要讨论WPF框架-Xamarin格式不支持x:Shared.

The link you mentioned talks primarily about WPF framework - I don't think x:Shared is supported in Xamarin forms.

为避免多次声明形状-您可以使用DataTemplate，并将其注册为StaticResource.

To avoid having to declare shape multiple times - you can make use of DataTemplate, and register that as a StaticResource.

然后，修改/扩展ImageButton以添加类型为DataTemplate的可绑定属性，该属性在设置时使用

And, modify/extend ImageButton to add a bindable property of type DataTemplate, which when set inflates the template into Shape object using CreateContent() method.

public DataTemplate ShapeTemplate
{
    get { return (DataTemplate)GetValue(ShapeTemplateProperty); }
    set { SetValue(ShapeTemplateProperty, value); }
}

public static readonly BindableProperty ShapeTemplateProperty = BindableProperty.Create(
    nameof(ShapeTemplate),
    typeof(DataTemplate),
    typeof(ImageButton),
    propertyChanged: (bObj, oldValue, newValue) =>
    {
        var view = bObj as ImageButton;
        if (view != null && newValue != null)
            view.Shape = (View)newValue.CreateContent();
    }
);

样品用量

<Grid.Resources>
 <ResourceDictionary>
   <DataTemplate x:Key="SpecCircleTemplate">
      <SharedShapes:Circle Color="{StaticResource AccentColor}"/>
   </DataTemplate>
 </ResourceDictionary>
</Grid.Resources>

<SharedControls:ImageButton Grid.Row="0" Grid.Column="0" 
    ShapeTemplate="{StaticResource SpecCircleTemplate}"...
<SharedControls:ImageButton Grid.Row="1" Grid.Column="0"
    ShapeTemplate="{StaticResource SpecCircleTemplate}"...

这篇关于Xamarin.Forms x:共享的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！