Xamarin Forms - 标签 TextColor 不会通过绑定更新

Question

所以，基本上，我有一个 Button 列表。当您单击其中之一时，其 Label TextColor 会发生变化。为了做到这一点，我使用 {Binding value} 然而，它不起作用..我试图抛出一个事件但是..没有任何反应..我试图直接从标签设置它并且它有效..为什么？

我在 C# 部分有这段代码：

private Color GroupSuperModLabelColor { get; set; }
private void OnGroupsClicked(object sender, EventArgs ea)
{
    if (GroupSuperModLabelColor == App.NL_White)
        GroupSuperModLabelColor = App.NL_OrangeBeer;
    else
        GroupSuperModLabelColor = App.NL_White;
    this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(GroupSuperModLabelColor)));

    //If I don't add this line, then it doesn't work, WHY?
    GroupLabel.TextColor = GroupSuperModLabelColor;

    Debug.WriteLine("OnGroupsClicked clicked !");
}

有XAML部分的声明：

<AbsoluteLayout HeightRequest="{Binding SuperModHeightSize}" WidthRequest="{Binding SuperModWidthSize}">
  <control:CustomLabel x:Name="GroupLabel" Text="Groups" FontFamily="{extension:FontFamily Roboto_Light}" FontSize="20" TextColor="{Binding GroupSuperModLabelColor}"
                       HorizontalTextAlignment="Center" VerticalTextAlignment="Center"
                       AbsoluteLayout.LayoutBounds="0.5, 0.5, 1, 1"
                       AbsoluteLayout.LayoutFlags="All"/>
  <control:CustomButton BackgroundColor="Transparent" BorderColor="Transparent"
                        Clicked="OnGroupsClicked" LongPress="OnGroupsLongPress"
                        AbsoluteLayout.LayoutBounds="0.5, 0.5, 1, 1"
                        AbsoluteLayout.LayoutFlags="All"/>
  </AbsoluteLayout>

我的 Binding context 设置为此，所有其他 Binding 东西都有效..只是颜色，它似乎不起作用..

为什么？提前致谢

Answer 1

您的 GroupSuperModLabelColor 未声明为可绑定属性：https://developer.xamarin.com/guides/xamarin-forms/xaml/bindable-properties/

您必须更改声明。

Xamarin Forms - 标签 TextColor 不会通过绑定更新

Xamarin Forms - Label TextColor doesn't update by Binding

c#

xaml

binding

textcolor