Kotlin报错:Out-projected type ... prohibits the use of ... defined in ...的解决方案

本书作者分享了在使用Kotlin开发Android应用时,遇到的BaseRecyclerViewAdapterHelper泛型问题及解决方案。区别于Java,Kotlin泛型使用需明确指定类型,避免编译错误。

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用Kotlin开发过程中使用BaseRecyclerViewAdapterHelper时候遇到如图问题:
在这里插入图片描述
这里说下Kotlin的泛型和Java泛型的区别,Java定义的泛型使用时可以省略,但是Kotlin必须要声明。我们看一下mAdapter变量的定义:

val mAdapter: BaseQuickAdapter<*, *> by lazy {
        getRepoAdapter()
    }

可以看到我们声明的泛型是星号,并没有指明具体的类型。
而我们在查看BaseQuickAdapter源码时可以看到这两个泛型有明确的类型界定:
在这里插入图片描述
解决方案就是,我们不能用星号来确定泛型类型,必须有明确的类型:

val mAdapter: BaseQuickAdapter<GithubEvent, BaseViewHolder> by lazy {
        getRepoAdapter()
    }
abstract fun getRepoAdapter(): BaseQuickAdapter<GithubEvent, BaseViewHolder>

然后代码就不会报错了:
在这里插入图片描述

2025-06-19 08:32:56 FAILURE: Build failed with an exception. * What went wrong: Execution failed for task ':app:checkReleaseDuplicateClasses'. > 1 exception was raised by workers: java.lang.RuntimeException: Duplicate class kotlin.ArrayIntrinsicsKt found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.BuilderInference found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.Deprecated found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.DeprecationLevel found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.DslMarker found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.ExceptionsKt found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.ExceptionsKt__ExceptionsKt found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.Experimental found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.Experimental$Level found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.ExperimentalMultiplatform found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.ExperimentalStdlibApi found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.ExperimentalUnsignedTypes found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.ExtensionFunctionType found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.Function found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.HashCodeKt found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.InitializedLazyImpl found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.KotlinNullPointerException found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.KotlinVersion found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.KotlinVersion$Companion found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.LateinitKt found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.Lazy found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.LazyKt found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.LazyKt$WhenMappings found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdlib-1.5.31.jar (org.jetbrains.kotlin:kotlin-stdlib:1.5.31) Duplicate class kotlin.LazyKt__LazyJVMKt found in modules jetified-kotlin-stdlib-1.3.50.jar (kotlin-stdlib-1.3.50.jar) and jetified-kotlin-stdli
最新发布
06-20
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