自定义视图上的多重触发器

Question

我创建了一个名为“InfoButton”的自定义视图：

public class InfoButton : ImageButton
{
    public string Glyph { get; set; } = "\U000F02FD";
    public string Title { get; set; }
    public string Text { get; set; }
    public InfoButton()
    {
        Source = new FontImageSource() { Glyph = Glyph, FontFamily = "materialdesign.ttf#materialdesign", Size= (double)new FontSizeConverter().ConvertFromInvariantString("Title"), Color = Color.Black };
        BackgroundColor = Color.Transparent;
        Clicked += InfoButton_Clicked;
    }

    private void InfoButton_Clicked(object sender, EventArgs e)
    {
        AlertPopup.DisplayAlertPopup(Title, Text, 0, "Close");
    }
}

现在我为它创建了一个触发器：

<models:InfoButton Glyph="&#xF059F;" Title="some title" Text="some text" IsVisible="false" HorizontalOptions="EndAndExpand">
    <models:InfoButton.Triggers>
        <MultiTrigger TargetType="{x:Type models:InfoButton}">
            <MultiTrigger.Conditions>
                <BindingCondition Binding="{Binding isPublic}" Value="true"/>
                <BindingCondition Binding="{Binding isReadonly}" Value="false"/>
            </MultiTrigger.Conditions>
            <MultiTrigger.Setters>
                <Setter Property="IsVisible" Value="true"/>
                <Setter Property="Glyph" Value="&#xF059F;"/>
            </MultiTrigger.Setters>
        </MultiTrigger>
    </models:InfoButton.Triggers>
</models:InfoButton>

但是我在编译时遇到这个错误:

XFC0001 Cannot resolve property "Glyph" on type "InfoButton (property missing or missing accessors)".

可能是什么问题？

感谢您的帮助。

Answer 1

要简单地解决您的问题，请转到 解决方案 部分。要了解您的代码失败的原因，请参阅说明部分。

解决方案

您必须将 Glyph 属性变成 BindableProperty，如下所示

public static readonly BindableProperty GlyphProperty = BindableProperty.Create(nameof(Glyph), typeof(string), typeof(InfoButton), "\U000F02FD");

public string Glyph
{
    get { return (string)GetValue(GlyphProperty); }
    set { SetValue(GlyphProperty, value); }
}

说明

可以在 the docu for Setter.Property 中找到 Glyph 定义为简单属性的代码失败的解释

Only bindable properties can be set with a Setter.

自定义视图上的多重触发器

multitrigger on custom view

c#

xamarin.ios

xamarin.android

xamarin

xamarin.forms

解决方案

说明