Xamarin.Forms change the color of the buttons and border color in alertDialog - xamarin.forms

Question

I have AlertDialog. Bu default the alertDialog is like this:
I want to change the color of OK button and add border color. Is there a solution for this customization .
This is my code:
await Application.Current.MainPage.DisplayAlert("Alert!", " This is DisplayAlert", "OK");

Answer 1

You could use [DependencyService] to call native AlerDialog and change it in specific platforms,here is a simple sample that change the color of the action button .
in Forms ,create the interface:
public interface IPopUp
{
void Popup(string title, string message,Color titleColor,Color messageColor,Color OKButtonColor ,EventHandler handler);
}
in iOS
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using App10.iOS;
using Foundation;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
using App10;
[assembly: Dependency(typeof(PopupImplemention))]
namespace App10.iOS
{
public class PopupImplemention : IPopUp
{
public void Popup(string title, string message, Color titleColor, Color messageColor, Color OKButtonColor, EventHandler handler)
{
UIAlertController alertController = UIAlertController.Create(title,message,UIAlertControllerStyle.Alert);
var firstAttributes = new UIStringAttributes
{
ForegroundColor =titleColor.ToUIColor(),
};
var secondAttributes = new UIStringAttributes
{
ForegroundColor =messageColor.ToUIColor(),
};
alertController.SetValueForKey(new NSAttributedString(title, firstAttributes), new NSString("attributedTitle"));
alertController.SetValueForKey(new NSAttributedString(message, secondAttributes), new NSString("attributedMessage"));
UIAlertAction cancelAction = UIAlertAction.Create("Cancel",UIAlertActionStyle.Cancel,null);
UIAlertAction okAction = UIAlertAction.Create("OK", UIAlertActionStyle.Default,(sender)=> { handler?.Invoke(sender, new EventArgs()) ; });
okAction.SetValueForKey(OKButtonColor.ToUIColor(), new NSString("_titleTextColor"));
alertController.AddAction(cancelAction);
alertController.AddAction(okAction);
var currentViewController = topViewControllerWithRootViewController(UIApplication.SharedApplication.Delegate.GetWindow().RootViewController);
currentViewController.PresentViewController(alertController,true,null);
}
UIViewController topViewControllerWithRootViewController(UIViewController rootViewController)
{
if (rootViewController is UITabBarController)
{
UITabBarController tabBarController = (UITabBarController)rootViewController;
return topViewControllerWithRootViewController(tabBarController.SelectedViewController);
}
else if (rootViewController is UINavigationController)
{
UINavigationController navigationController = (UINavigationController)rootViewController;
return topViewControllerWithRootViewController(navigationController.VisibleViewController);
}
else if (rootViewController.PresentedViewController != null)
{
UIViewController presentedViewController = rootViewController.PresentedViewController;
return topViewControllerWithRootViewController(presentedViewController);
}
else
{
return rootViewController;
}
}
}
}
in Android
in MainActivity
public static MainActivity Intance;
protected override void OnCreate(Bundle savedInstanceState)
{
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(savedInstanceState);
Intance = this;
Xamarin.Essentials.Platform.Init(this, savedInstanceState);
global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
LoadApplication(new App());
}
using Xamarin.Forms;
using xxx;
using xxx.Droid;
using Android;
using System;
using Xamarin.Forms.Platform.Android;
using Android.Support.V7.App;
using Android.Text;
[assembly: Dependency(typeof(PopupImplemention))]
namespace xxx.Droid
{
public class PopupImplemention : IPopUp
{
public void Popup(string title, string message, Color titleColor, Color messageColor, EventHandler handler)
{
// because html.string could not support format string , so you need to set the color directly in the string with a static value
Android.Support.V7.App.AlertDialog.Builder alert = new Android.Support.V7.App.AlertDialog.Builder(MainActivity.Intance);
alert.SetTitle(title);
alert.SetMessage(message);
alert.SetPositiveButton(Html.FromHtml("<font color='#0000ff'>OK</font>"), (senderAlert, args) =>
{
handler?.Invoke(senderAlert, args);
});
Android.Support.V7.App.AlertDialog dialog = alert.Create();
dialog.Show();
}
}
}
And call it in forms
DependencyService.Get<IPopUp>().Popup("Title","xxxxxxxxxxxx",Color.Red,Color.Blue,Color.Green,(sen,args)=> {
// handle the logic when clikc the OK button
});

Answer 2

You can use cross platform libraries like this one: https://github.com/aritchie/userdialogs

Answer 3

You will need to create a styles.xml and configure it for Android that way. There is currently no way to customize that native control through any of the Xamarin.Forms API's as far as I am aware.
Example:
<style name="AppCompatAlertDialogStyle" parent="Theme.AppCompat.Dialog.Alert">
<item name="colorAccent">#c7ac56</item>
<item name="android:textColor">#c7ac56</item>
<item name="android:background">#5c8487</item>
</style>
Here is a good tutorial on an example on how to do this: http://gmariotti.blogspot.com/2015/04/a-material-styled-alertdialog.html
If you are using Xamarin Android you probably could also hook into the AlertDialog.Builder and set the proprieties pro grammatically: https://developer.android.com/reference/android/app/AlertDialog.Builder