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

Question

Im using DataBinding Api for setting the views in android layouts. Here is my layout.

layout.xml

<?xml version="1.0" encoding="utf-8"?>
 <layout xmlns:android="http://schemas.android.com/apk/res/android">
  <data>
    <variable name="user" type="testing.sampleapp.com.sampleapp.User"/>
  </data>
<LinearLayout
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@{ "Hello " + user.firstName}"/>
</LinearLayout>

I want the TextView to display Hello UserName. How to achieve this using the data binding api.

Ravi · Accepted Answer · 2019-05-15T03:26:40.130

308

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

edited May 15 '19 at 03:26

answered Oct 14 '16 at 09:41

Ravi

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Yeah it worked. Thanks . I was using single inverted comma ('). Grave accent(`) worked for me. – Sasank Sunkavalli Oct 14 '16 at 09:46
@SasankSunkavalli glad to help you :) , always use grave accent for string when using DataBinding. – Ravi Oct 14 '16 at 09:47
1

I don't get it. On my .xml this method, as well as any other methods on this page, is not even close to being functional. All it does is prints as : `@{`Hello ` + user.firstName}` – ekashking Nov 04 '19 at 03:34
This is DataBinding? – IgorGanapolsky Dec 27 '19 at 22:10

score 88 · Answer 2 · edited Aug 17 '20 at 10:48

88

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>

edited Aug 17 '20 at 10:48

iCantC

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answered Apr 16 '18 at 19:37

Prakash

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great! thnx wery – Serg Burlaka Sep 19 '18 at 11:16
thats what I'm looking for :) – Edgar Khimich Mar 25 '19 at 02:35

Khemraj Sharma · Answer 3 · 2020-11-30T10:52:59.860

Many ways to concat strings

1. Using string resource (Most preferable because of localization)

android:text= "@{@string/generic_name(user.name)}"

Just make string resource like this.

<string name="generic_name">Hello %s</string>

2. Hard coded concat

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

3. Using `String`'s concat method

android:text="@{user.firstName.concat(@string/space).concat(user.lastName)}"

Here space is an html entity which is placed inside strings.xml. Because XML does not accept Html entities or special characters directly. (Link Html Entities)

<string name="space">\u0020</string>

4. Using `String.format()`

android:text= "@{String.format(@string/hello, user.name)}"

you have to import String class in layout in this type.

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <import type="String" />
    </data>
    <TextView
        android:text= "@{String.format(@string/hello, user.name)}"
        ... >
    </TextView>
</layout>

5. Another method

android:text="@{@string/generic_name(user.firstName,user.lastName)}"

In this case put a string resource in strings.xml

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

There can be many other ways, choose one you need.

Option 1 worked for me. Option 4 didn't work. If you have a narrow adapter, I recommend Option 1. — rminaj, Jul 12 '19 at 09:30

score 12 · Answer 4 · answered Jul 27 '17 at 15:05

12

Since xml supports single quotes for values of attribute, you can also do this :

android:text='@{"Hello "+user.firstName}'

answered Jul 27 '17 at 15:05

ArJ

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Yogesh Rathi · Answer 5 · 2018-08-13T13:59:50.020

7

There are two ways.

First Solution

concat with grave accent (`)

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

Second Solution

Declare Your string in strings.xml

like "Hello %1$s , (whatever you want to add then add here)".

amd use String.format(stringResource, upsatename);

edited Aug 13 '18 at 13:59

answered Oct 14 '16 at 09:42

Yogesh Rathi

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I know this would work, But i want to use the concat way – Sasank Sunkavalli Oct 14 '16 at 09:43
25

You can also use formatted string resources in the expression: `android:text="@{@string/hello(user.firstName)}"` – George Mount Oct 14 '16 at 20:44
it's %1$s instead of %$1s... ;) – Rik van Velzen Jul 06 '18 at 10:11

score 7 · Answer 6 · answered Dec 26 '19 at 08:21

7

In case of static string and other dynamic you can use this

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

In case of dynamic data you can use this.

android:text='@{user.firstName+" "+user.lastName}'

answered Dec 26 '19 at 08:21

kishan verma

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score 4 · Answer 7 · answered Aug 09 '17 at 09:19

To do a concat in xml layout:

<data>

/*This is used for android view*/
<import type="android.view.View" />

/*This is used for android resources*/
<import type="com.myapp.R" />

/*This is app context*/
<variable
    name="context"
    type="android.content.Context" />

/*This is used for model data*/
<variable
    name="item"
    type="com.myapp.models.Chapter" />
</data>

android:text="@{item.serialNo.concat(@string/space).concat(item.title)}"

In strings.xml I have added code for blank space:

<string name="space">\u0020</string>

score 4 · Answer 8 · answered Jun 01 '18 at 09:11

4

if you want to concat String resource with data from your model, you can do it in such way:

 android:text='@{@string/release_date+model.release_date}'

answered Jun 01 '18 at 09:11

Jackky777

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Aziz · Answer 9 · 2019-11-24T12:47:10.973

0

The simplest way I found to be is to replace ''(single) in place of ""(double), For Eg. You have two variables,

<variable name="a" type="String" />
<variable name="b" type="String" />

Now to concatenate,

android:text='a + " " + b}'

edited Nov 24 '19 at 12:47

answered Sep 30 '19 at 10:18

Aziz

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score 0 · Answer 10 · answered Dec 07 '20 at 12:48

0

Probably late to the party: Below code will also work

android:text='@{@string/hello.concat(user.firstName)}'

answered Dec 07 '20 at 12:48

madroid

336
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score 0 · Answer 11 · answered May 28 '22 at 08:02

0

Few cents from me

If you want to check null and set default value try this answer

 android:text='@{(user.first_name ?? "") +" "+ (user.last_name ?? "")}'

answered May 28 '22 at 08:02

Ranjithkumar

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

11 Answers11

Many ways to concat strings

1. Using string resource (Most preferable because of localization)

2. Hard coded concat

3. Using `String`'s concat method

4. Using `String.format()`

5. Another method

Linked

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

11 Answers11

Many ways to concat strings

1. Using string resource (Most preferable because of localization)

2. Hard coded concat

3. Using String's concat method

4. Using String.format()

5. Another method

Linked

3. Using `String`'s concat method

4. Using `String.format()`