Android Data Binder bug: androidbinder

Android Data Binder bug: androidbinder

Following the official tutorial to learn how to use data binding, the function is indeed very powerful. This is a huge step for Android to become MVVM and a small step for Native development to move closer to the Web.

One of the binding methods is to directly use resource data, for example:

android:padding="@{large? @dimen/largePadding : @dimen/smallPadding}"

Official Tutorial:

The layout file of the full version is as follows:

<layout xmlns:android="http://schemas.android.com/apk/res/android">    <data class="ResourceBinding">        <variable name="large" type="boolean" />    </data>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent">        <TextView            android:padding="@{large? @dimen/largePadding : @dimen/smallPadding}"            android:background="@android:color/black"            android:textColor="@android:color/white"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@string/hello_world" />    </LinearLayout></layout>

largePaddingAndsmallPaddingAll are defined indimens.xmlFile.

<dimen name="largePadding">20dp</dimen><dimen name="smallPadding">5dp</dimen>

Bind the large variable in the Java code and assign the valueture.

@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);   ResourceBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_resource);    binding.setLarge(true);} 

Theoretically, this should be fine, but an error occurs during the Run project. The error message is as follows:

cannot find the setter for attribute 'android:padding' on android.widget.TextView with parameter type float.

It seems like DataBinder@dimen/largePaddingResolvedfloatType, you can try type conversion:

android:padding="@{large? (int)@dimen/largePadding : (int)@dimen/smallPadding}"

After compilation is passed, the running result is correct. It should be a bug in DataBinder. The original resource binding has such advanced usage, and type conversion can be performed directly-(int)@dimen/largePadding.

It feels amazing. You must read the source code to understand how DataBinder works.