Xamarin Forms Searchbar iOS 13 忽略背景颜色

Question

似乎最新版本的 iOS (13) 忽略了搜索栏背景颜色？

iOS 13 Changes to UISearchBar tint's, can't achieve the same outcome

我正在使用它，它适用于以下所有版本，但在 13 上它会忽略背景颜色并使其变为白色

  <SearchBar HeightRequest="35" BackgroundColor="#2A4880" TextColor="White"></SearchBar>

这是一个已知的问题？有解决办法吗？

Answer 1

您可以通过创建 PlatformEffect 来解决这个问题。 :

App.xaml.cs

[assembly: ResolutionGroupName("ProjectName")]
namespace ProjectName.App
{
    public partial class App : Application
    {
        ...

共享项目:

public class SearchBarBackgroundEffect : RoutingEffect
    {
        public SearchBarBackgroundEffect() : base("ProjectName.SearchBarBackgroundEffect") { }
    }

iOS项目:

[assembly: ExportEffect(typeof(SearchBarBackgroundPlatformEffect), "SearchBarBackgroundEffect")]
 public class SearchBarBackgroundPlatformEffect : PlatformEffect
    {
        private UISearchBar NativeSearchBar => (UISearchBar)Control;
        private SearchBar XamarinSearchBar => (SearchBar)Element;

        protected override void OnAttached()
        {
            if (UIDevice.CurrentDevice.CheckSystemVersion(13, 0))
                NativeSearchBar.SearchTextField.BackgroundColor = XamarinSearchBar.BackgroundColor.ToUIColor();
        }

        protected override void OnDetached()
        {
             // Intentionally left blank.
        }
    }

XAML 文件

 <SearchBar>
                <SearchBar.Effects>
                    <effects:SearchBarBackgroundEffect />
                </SearchBar.Effects>
            </SearchBar>