Styjun

I'm using Xamarin.UITest to write some automation.
The target app has this in its markup:

<ContentPage.ToolbarItems>
 <ToolbarItem Icon="Settings" AutomationId="SettingsToolbarItem" Order="Primary" Priority="1" Command="Binding ShowSettingsCommand" />
</ContentPage.ToolbarItems>

So far I've had 3 approaches:

Using .Class and Indexing successfully finds the element

systemMenuButton = x => x.Class("android.support.v7.view.menu.ActionMenuItemView").Index(1);

Using .Property fails to find the element

systemMenuButton = e => e.Property("Command", "ShowSettingsCommand");

Similarly, using .Marked also fails to find the element

systemMenuButton = x => x.Marked("SettingsToolbarItem");

Relevant automation code is as follows:

using Query = System.Func<Xamarin.UITest.Queries.AppQuery, Xamarin.UITest.Queries.AppQuery>;
....
protected readonly Query systemMenuButton = x => x.Marked("SettingsToolbarItem");
....
app.Tap(systemMenuButton);

I get a generic "unable to find element" exception:

Unable to find element. Query for Marked("SettingsToolbarItem") gave no results.

I don't get this exception when clicking on other elements outside the ContentPage.ToolbarItems block on the same View/Page

I've hit the same problem - for some reason Android can't detect ToolbarItem.AutomationId.

A workaround is to assign ToolbarItem.Text the same value as ToolbarItem.AutomationId.

Xamarin.Forms.ContentPage

<ContentPage.ToolbarItems>
 <ToolbarItem Icon="Settings" Text="SettingsToolbarItem" AutomationId="SettingsToolbarItem" Order="Primary" Priority="1" Command="Binding ShowSettingsCommand" />
</ContentPage.ToolbarItems>

Xamarin.UITest

using Query = System.Func<Xamarin.UITest.Queries.AppQuery, Xamarin.UITest.Queries.AppQuery>;
// ....
protected readonly Query systemMenuButton = x => x.Marked("SettingsToolbarItem");
//....

public void TapSystemMenuButton()

 app.Tap(systemMenuButton);

 app.Screenshot("Tapped System Menu Button");

Here's is a sample app where I use similar logic to tap a ToolbarItem in a UITest: https://github.com/brminnick/InvestmentDataSampleApp/

Edit

In the comments, you mentioned that you do not have access to the source code of the Xamarin.Forms app.

If you are unable to change the Xamarin.Forms source code, you will have to use x => x.Class("ActionMenuItemView").Index(1).

I don't recommend going this route because the int parameter of Index can vary depending on the device; it is not guaranteed to always be 1.

public void TapSystemMenuButton()

 if (app is iOSApp)
 app.Tap(systemMenuButton);
 else
 app.Tap(x => x.Class("ActionMenuItemView").Index(1));

 app.Screenshot("Tapped System Menu Button");