android - 类型不匹配。必需 : Nothing Found: Callback<*>

Question

在我的 Android 项目中:

import retrofit2.Call
import retrofit2.Callback

    fun getAdvertising(callback: Callback<List<Advertising>>) {
        val call = tangoRestClient.advertising
        executeAsync(call, callback)
    }

    private fun executeAsync(call: Call<*>, callback: Callback<*>) {
        call.enqueue(callback)  // compile error
    }

但是我得到编译错误:

> Task :app:generateDebugSources
> Task :app:validateSigningDebug

> Task :transport:compileDebugKotlin FAILED
e: \TransportService.kt: (127, 14): Out-projected type 'Call<*>' prohibits the use of 'public abstract fun enqueue(p0: Callback<T!>!): Unit defined in retrofit2.Call'

FAILURE: Build failed with an exception.

Answer 1

是的，Call 和 Callback 的类型参数应该相同。您必须编写 executeAsync 函数，例如如下所示:

private fun <T> executeAsync(call: Call<T>, callback: Callback<T>) {
    call.enqueue(callback)  // no compile error
}

它将保证类型参数相同