Android how to use a string variable inside a textview with data binding

Question

Good day, I am practising my skills using layout, just learned data binding, and I want to know how I can use a variable like defaultName within a textview, so I am trying to do this:

android:text="@={`hi `+ myName.defaultName}"

I want the output to be:

hi Travis Scott

But instead I get a nasty error which is this:

cannot find symbol class ActivityMainBindingImpl
import com.example.nickname.databinding.ActivityMainBindingImpl;
[databinding] {"msg":"The expression \u0027(\"hi \") + (myNameDefaultName)\u0027 cannot be inverted, so it cannot be used in a two-way binding\n\nDetails: Two-way binding with string concatenation operator (+) only supports the empty string constant (`` or \"\")","file":"app\\src\\main\\res\\layout\\activity_main.xml","pos":[{"line0":27,"col0":25,"line1":27,"col1":49}]}
                                       ^

I researched the error, I didn't find the solution. I researched what alternatives people have used to this problem and I didn't find anything. The only thing I found was this "@={hi + myName.defaultName}" and that's it.

My working code is `android:text='@{"Search " + model.dailogBean.title}'`. — rahat, Jan 21 '21 at 17:26
I just tried that, I replaced "text" with "hint" and still the same error — meniman98, Jan 21 '21 at 17:28
I was using for hint property, you can use for text property — rahat, Jan 21 '21 at 17:29
Your exact answer `android:text='@{"hi " + myName.defaultName}'` — rahat, Jan 21 '21 at 17:30
Yes, myName is the model in this case, and defaultName is a string — meniman98, Jan 21 '21 at 17:31
Does this answer your question? [How do I use databinding to combine a string from resources with a dynamic variable in XML?](https://stackoverflow.com/questions/38978499/how-do-i-use-databinding-to-combine-a-string-from-resources-with-a-dynamic-varia) — Sekiro, Jan 21 '21 at 17:45
How the `TextView` value gonna change? It's value gets updated only when you set the text by calling `setText`. — Rajnish suryavanshi, Jan 21 '21 at 17:52

score 2 · Accepted Answer · answered Jan 21 '21 at 17:51

2

You are trying to two-way binding instead of one-way binding. Just remove "=" sign and change braskets

android:text='@{"hi" + item.title}'

answered Jan 21 '21 at 17:51

i30mb1

3,894
3
18
34

1

Goodness, that solved the issue. I got rid of the "=" and it worked. Now it says exactly what I need it to say, thank you so much! – meniman98 Jan 21 '21 at 17:56

Android how to use a string variable inside a textview with data binding

1 Answers1