I want to concat two strings for a TextView in android, Data Binding Api

concate it with grave accent (`)

android:text="@{`Hello ` + user.firstName}"/>

You can concat it in multiple ways, check it here concat-two-strings-in-textview-using-databinding

This is already answered by @GeorgeMount in comments to one of the solution. Which to me looks like the best solution so far here.

android:text="@{@string/location(user.city,user.state)}"

in your strings.xml

<string name="location">%1$s, %2$s</string>