在Kotlin中绑定具有多个参数的适配器

Question

To use multiple arguments for a data binding adapter the Java syntax is

@BindingAdapter(value={"arg1", "arg2"}, requireAll = false)

However this does not compile in Kotlin:

Error:(13, 37) Unexpected tokens (use ';' to separate expressions on the same line)

what's the correct syntax for multiple arguments in Kotlin?

Answer 1

Should be:

@BindingAdapter(value=*arrayOf("arg1", "arg2"), requireAll = false)

Please refer to the official annotations docs for Java Annotations in Kotlin

Quoting:

For other arguments that have an array type, you need to use arrayOf explicitly:

// Java
public @interface AnnWithArrayMethod {
    String[] names();
}


// Kotlin
@AnnWithArrayMethod(names = arrayOf("abc", "foo", "bar")) class C

EDIT: Credit to @Francesc

Answer 2

Or you can just simply do this

@BindingAdapter("arg1", "agr2", "agr3", "agr4", requireAll = false)

as pointed in Android Official Docs

Answer 3

从Kotlin 1.2你可以做到

@BindingAdapter(value = ["arg1", "arg2"], requireAll = false)

Answer 4

You can also do it by this way:

@BindingAdapter(value= ["deckBackgroundAsFirstParameter", "typeAsSecondParameter"], requireAll = false) 
fun loadBackgroundMethodNameForExample(imageViewForExample: ImageView, deckBackgroundAsFirstParameter: Int?, typeAsSecondParameter: Int?) {
   ...
}

where value is an array of the parameters that you want to use.