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

问题

I've been experimenting all day and trying to figure out just how to get my UISearchBar to appear the same in iOS13 as it appears in iOS12/11

So the way the search bar is added is simply a new UISearchController.

            var searchController = new UISearchController(searchResultsController: null);
            searchController.SearchBar.Placeholder = "Search";
            searchController.SearchResultsUpdater = this;
            searchController.HidesNavigationBarDuringPresentation = false;
            searchController.DimsBackgroundDuringPresentation = false;

            NavigationItem.SearchController = searchController;
            NavigationItem.HidesSearchBarWhenScrolling = false;

The results on iOS 11/12:

The results on iOS 13:

On iOS 13 I am using the new UINavigationBarAppearance code like this:

                var appearance = new UINavigationBarAppearance();
                appearance.ConfigureWithOpaqueBackground();
                appearance.BackgroundColor = ColorPalette.TintColor;
                appearance.TitleTextAttributes = new UIStringAttributes { ForegroundColor = UIColor.White };

                NavigationItem.StandardAppearance = appearance;

On iOS 11/12 I am using legacy way to achieve it:

                NavigationController.NavigationBar.BarStyle = UIBarStyle.Black;
                NavigationController.NavigationBar.TintColor = UIColor.White;
                NavigationController.NavigationBar.BarTintColor = ColorPalette.TintColor;
                NavigationController.NavigationBar.Translucent = false;

I've tried a number of things, but can't seem to get the UISearchBar to tint by itself how iOS11/12 achieves it.

I know that the new UISearchBar now has access to the UITextField and I can configure the background color's etc.

回答1:

There were several properties added in iOS 13, so you need to use them with the help of a conditional. For changing the background color, you have to use the BackgroundColor property of the SearchBar, like this

searchController.SearchBar.BackgroundColor = UIColor.Red;

回答2:

On iOS 13, you have access to the internal UISearchTextField through the SearchTextField property, you can set it's background directly (in my case, I need the background to be white). Be sure to check the iOS version to avoid exceptions.

if(UIDevice.CurrentDevice.CheckSystemVersion(13,0))
{
    searchController.SearchBar.SearchTextField.BackgroundColor = UIColor.White;
}

回答3:

Use a custom renderer and override the OnElementChanged method this way

protected override void OnElementChanged(ElementChangedEventArgs<SearchBar> e)
{
  base.OnElementChanged(e);
  if (Control != null)
  {
    if(UIDevice.CurrentDevice.CheckSystemVersion(13,0))
      Control.SearchTextField.BackgroundColor = Element.BackgroundColor.ToUIColor();
  }
}

later on, you don't have to do anything else and worked for me on ios 12 and ios 13+

来源：https://stackoverflow.com/questions/58229829/ios-13-changes-to-uisearchbar-tints-cant-achieve-the-same-outcome