DataBinding:如何通过动态 id 获取资源? [英] DataBinding: How to get resource by dynamic id?

问题描述

我知道可以通过资源 ID 引用布局中的资源:

I know that it is possible to reference resources in layout by their resource id:

android:text="@{@string/resourceName}"

但是，我想通过仅在运行时已知的 id 来引用资源.作为一个简单的例子，假设我们有这样的模型:

However, I would like to reference resource by id which is known only at runtime. As a simple example, imagine we have such model:

public class MyPOJO {

    public final int resourceId = R.string.helloWorld;

}

现在我需要将此值用作格式字符串中的值.让我们称之为

And now I need to use this value as a value in a format string. Let's call it

<string name="myFormatString">Value is: %s</string>

最直接的方法不起作用:

The most straightforward approach does not work:

android:text="@{@string/myFormatString(myPojo.resourceId)}"

这只会将整数值放入占位符(这也证明我正确初始化了我的 POJO，所以我没有在这里提供整个布局).

This will just put integer value into placeholder (also it proves that I initialized my POJO correctly, so I'm not providing whole layout here).

我也尝试过使用 @BindingConversion，但它没有奏效(这实际上是预期的，但我还是尝试了) - int 仍然被分配给占位符和绑定方法没有被调用.

I also tried using @BindingConversion, but it did not worked (which is actually expected, but I tried anyway) - int was still assigned to placeholder and binding method was not called.

如何通过 DataBinding 库中的 id 显式获取资源?

How can I explicitly get resource by it's id in DataBinding library?

推荐答案

我最终创建了自己的方法:

I ended up creating my own method:

public class BindingUtils {

    public static String string(int resourceId) {
        return MyApplication
                .getApplication()
                .getResources()
                .getString(resourceId);
    }

}

为其声明导入:

<data>

    <import type="com.example.BindingUtils" />

    ...

</data>

并且只是在绑定期间调用它:

And just calling it during binding:

android:text="@{@string/myFormatString(BindingUtils.string(myPojo.resourceId))}"

如果有开箱即用的方法就好了.DataBinding 还处于 Beta 阶段 - 所以也许将来会出现.

Would be nice to have out-of-the-box method for that. DataBinding is sitll in Beta - so maybe it will come in future.

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