Cannot set string array for spinner using Android data binding

Question

I have a spinner now and I want to load the data to the spinner with data binding feature. I tried to find the way to declare the string array in the XML(https://developer.android.com/topic/libraries/data-binding/index.html#expression_language) but no satisfied result is found.

<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:apps="http://schemas.android.com/apk/res-auto">

<data>
    <import type="android.util.SparseArray"/>
    <variable
        name="statuslist"
        type="SparseArray<String>"/>
</data>
...
<android.support.v7.widget.AppCompatSpinner
        android:id="@+id/spn_status"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignStart="@+id/spinner1"
        android:layout_below="@+id/btn2"
        android:entries="@{statuslist}"
        apps:adapter="@{statusAdapter}"/>
</layout>

When it is build, the following error is shown.

Error:Execution failed for task ':app:dataBindingProcessLayoutsDebug'.

org.xml.sax.SAXParseException; systemId: file:/C:/Users/../app/build/intermediates/res/merged/debug/layout/testdialog.xml; lineNumber: 24; columnNumber: 30; The value of attribute "type" associated with an element type "null" must not contain the '<' character.

However, there is something confused.

1. When I tried to use SparseArray as shown on website. I found a "Cannot resolve sysmbol" in Android Studio XML Editor.
2. I do not know is it the correct way to setup the array value for the spinner since there is no official instructions for the spinner data bindingin the website.

Dibble

Have you enable databinding in build.gradle? – Enphytotic

Yes, I enable databinding in build.gradle. Here is the information of my Android Studio (Version: 2.1.2, JavaVersion : 1.7) – Dibble

Answer 1

have you import the SparseArray ?

try this :

<data><import type="android.util.SparseArray"/></data>

Pumpkin

I forgot to add this statement in the question. I tried this but it doesn't work – Dibble

SparseArray<String> change to SparseArray&lt;String> , try again – Pumpkin

Tried this way and it still not work. "Cannot resolve symbol" error is still shown – Dibble

< is a reserved character in xml. Can you omit the type of the SparseArray. Not like it exists in the compiled code anyway. – Woeful

What I meant is instead of SparseArray<String> write just SparseArray in the type field. – Woeful

That's kind of weird , I remember when my Android Studio is V1.5 , it works, but now have the same problem , Android Studio is V2.1 , is that a bug or something ? I wonder – Pumpkin

@GPuschka, if I use the SparseArray without type , doesn't it mean this variable is not type safety? That would not be solved if I use the custom object (SparseArray<Customer>) – Dibble

Answer 2

This is a very simple way to setup a spinner with a string-array from your resource's array.xml

<Spinner
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:entries="@array/spinner_array_items"/>

The spinner_array_items should contain a list of items to be found in the spinner dropdown.

Seismography

Answer 3

Change SparseArray<String> to SparseArray<String>.

Apophyllite

Answer 4

Well my implementation logic is based on your's but used ArrayList instead SparseArray.

XML:

    <data>
        <import type="java.util.ArrayList" />
        <variable
            name="cities"
            type="ArrayList&lt;String>"
        />        
    </data>

    <!-- Location -->
    <Spinner
        android:id="@+id/dd_city"
        android:entries="@{cities}"
        style="@style/dropdown"
    />

Now, we just need to bind our ArrayList to cities variable through Binding Class.

At least data will be bind : ).

TC.

Commutative