java.lang.IllegalArgumentException: Number of fn:sendMessage parameters does not match. Expected: 1, Actual: 2

[danatechgithub4]

这是网络请求的伪代码

interface APIDefinition

data class GetUserMessage(val name: String) : APIDefinition

data class DeleteUserMessage(val userId: Int = 0) : APIDefinition

@WorkerThread
suspend fun <T : APIDefinition> T.sendMessage(): T {
    return withContext(Dispatchers.IO) {
        // IO 操作
        println("Send message: ${this@sendMessage}")
        this@sendMessage
    }
}

@Composable
fun AutoCustom() {
    val (userInfo, loading, error) = useRequest(
            requestFn = GetUserMessage::sendMessage.asRequestFn(),
            optionsOf {
                defaultParams = arrayOf(GetUserMessage("Hello, World"))
            }
    )
    Column {
        Text(text = "Auto:")
        Spacer(modifier = Modifier.height(10.dp))
        if (loading) {
            Text(text = "user info loading ...")
        }
        if (userInfo.asBoolean()) {
            Text(text = userInfo.toString())
        }
        if (error.asBoolean()) {
            Text(text = "error: ${error.message}")
        }
    }
}

这是报错日志。

20:05:09.481  E  OnError: 
                 java.lang.IllegalArgumentException: Number of fn:sendMessage parameters does not match. Expected: 1, Actual: 2
                 	at xyz.junerver.compose.hooks.utils.LegalcheckKt.checkIsLegalParameters(legalcheck.kt:31)
                 	at xyz.junerver.compose.hooks.TypesKt.synthesisParametersAndCheck(types.kt:95)
                 	at xyz.junerver.compose.hooks.TypesKt.asSuspendNoopFn$run(types.kt:89)
                 	at xyz.junerver.compose.hooks.TypesKt.access$asSuspendNoopFn$run(types.kt:1)
                 	at xyz.junerver.compose.hooks.TypesKt$asSuspendNoopFn$2.invoke(types.kt:90)
                 	at xyz.junerver.compose.hooks.TypesKt$asSuspendNoopFn$2.invoke(types.kt:90)
                 	at xyz.junerver.compose.hooks.userequest.Fetch$_runAsync$2$2.invokeSuspend(Fetch.kt:156)
                 	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
                 	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:108)
                 	at androidx.compose.ui.platform.AndroidUiDispatcher.performTrampolineDispatch(AndroidUiDispatcher.android.kt:81)
                 	at androidx.compose.ui.platform.AndroidUiDispatcher.access$performTrampolineDispatch(AndroidUiDispatcher.android.kt:41)
                 	at androidx.compose.ui.platform.AndroidUiDispatcher$dispatchCallback$1.run(AndroidUiDispatcher.android.kt:57)
                 	at android.os.Handler.handleCallback(Handler.java:900)
                 	at android.os.Handler.dispatchMessage(Handler.java:103)
                 	at android.os.Looper.loop(Looper.java:219)
                 	at android.app.ActivityThread.main(ActivityThread.java:8673)
                 	at java.lang.reflect.Method.invoke(Native Method)
                 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
                 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1109)

下面是Kotlin的Test

import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import kotlin.reflect.KFunction
import kotlin.reflect.full.callSuspend
import kotlin.reflect.jvm.isAccessible

fun <T> KFunction<T?>.asSuspendNoopFn(): suspend (Array<Any?>) -> T? = { params: Array<Any?> ->
    this.isAccessible = true
    if (this.isSuspend) {
        this.callSuspend(*params)
    } else {
        this.call(*params)
    }
}

object NoopFnTest {
    suspend fun printHelloWord(): GetUserMessage {
        return withContext(Dispatchers.IO) {
            println("Hello, World")
            GetUserMessage("Hello, World")
        }
    }

    suspend fun deleteUser(userId: Int): DeleteUserMessage {
        return withContext(Dispatchers.IO) {
            println("Delete user: $userId")
            DeleteUserMessage(userId)
        }
    }
}

interface APIDefinition

data class GetUserMessage(val name: String) : APIDefinition

data class DeleteUserMessage(val userId: Int = 0) : APIDefinition

suspend fun <T : APIDefinition> T.sendMessage(): T {
    return withContext(Dispatchers.IO) {
        // IO 操作
        println("Send message: ${this@sendMessage}")
        this@sendMessage
    }
}

suspend fun main() {
    val noopFunction2 = NoopFnTest::printHelloWord.asSuspendNoopFn()
    noopFunction2(arrayOf())
    val noopFunction3 = NoopFnTest::deleteUser.asSuspendNoopFn()
    noopFunction3(arrayOf(1))
    val noopFunction4 = GetUserMessage::sendMessage.asSuspendNoopFn()
    noopFunction4(arrayOf(GetUserMessage("Hello, World")))
}

[danatechgithub4]

漏了一步，修改如下：

fun <T : APIDefinition> KFunction<T>.asRequestFn2() = this.asSuspendNoopFn()

@Composable
fun AutoCustom() {
    val (userInfo, loading, error) = useRequest(
            requestFn = GetUserMessage::sendMessage.asRequestFn2(),
            optionsOf {
                defaultParams = arrayOf(GetUserMessage("Hello, World"))
            }
    )
    Column {
        Text(text = "Auto:")
        Spacer(modifier = Modifier.height(10.dp))
        if (loading) {
            Text(text = "user info loading ...")
        }
        if (userInfo.asBoolean()) {
            Text(text = userInfo.toString())
        }
        if (error.asBoolean()) {
            Text(text = "error: ${error.message}")
        }
    }

报错信息

20:14:49.173  E  OnError: 
                 java.lang.IllegalArgumentException: Parameter at index 0 has incorrect type. Expected: T, Actual: xyz.junerver.composehooks.example.request.GetUserMessage
                 	at xyz.junerver.compose.hooks.utils.LegalcheckKt.checkIsLegalParameters(legalcheck.kt:42)
                 	at xyz.junerver.compose.hooks.TypesKt.synthesisParametersAndCheck(types.kt:95)
                 	at xyz.junerver.compose.hooks.TypesKt.asSuspendNoopFn$run(types.kt:89)
                 	at xyz.junerver.compose.hooks.TypesKt.access$asSuspendNoopFn$run(types.kt:1)
                 	at xyz.junerver.compose.hooks.TypesKt$asSuspendNoopFn$2.invoke(types.kt:90)
                 	at xyz.junerver.compose.hooks.TypesKt$asSuspendNoopFn$2.invoke(types.kt:90)
                 	at xyz.junerver.compose.hooks.userequest.Fetch$_runAsync$2$2.invokeSuspend(Fetch.kt:156)
                 	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
                 	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:108)
                 	at androidx.compose.ui.platform.AndroidUiDispatcher.performTrampolineDispatch(AndroidUiDispatcher.android.kt:81)
                 	at androidx.compose.ui.platform.AndroidUiDispatcher.access$performTrampolineDispatch(AndroidUiDispatcher.android.kt:41)
                 	at androidx.compose.ui.platform.AndroidUiDispatcher$dispatchCallback$1.doFrame(AndroidUiDispatcher.android.kt:68)
                 	at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1278)
                 	at android.view.Choreographer.doCallbacks(Choreographer.java:1019)
                 	at android.view.Choreographer.doFrame(Choreographer.java:907)
                 	at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1248)
                 	at android.os.Handler.handleCallback(Handler.java:900)
                 	at android.os.Handler.dispatchMessage(Handler.java:103)
                 	at android.os.Looper.loop(Looper.java:219)
                 	at android.app.ActivityThread.main(ActivityThread.java:8673)
                 	at java.lang.reflect.Method.invoke(Native Method)
                 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
                 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1109)

[junerver]

反编译下kt文件就明白了，最好不要用扩展函数做 requestFn 的参数，徒增心智负担

[danatechgithub4]

没明白作者的意思，

多谢作者好意，多数不会用扩展函数发起网络请求的，偶尔会偷个懒少些一点模板代码。

解决办法就是：自己copy一下作者代码。

fun <T : APIDefinition> KFunction<T>.asRequestFn2(instance: Any? = null): suspend (TParams) -> T {
    require(this.isSuspend) { "The function type is incorrect, and it must be a 'suspend' function" }
    suspend fun run(params: TParams): T =
            this.callSuspend(*instance?.let { arrayOf(it, *params) } ?: params)
    return ::run
}

[junerver]

字节码下无魔法，扩展函数Receiver.extendFun()反编译过来就是一个普通的静态函数static extendFun(Receiver obj)；

suspend 修饰的函数，还会再加一个参数，这就是为什么你的函数在报错时提示期望两个参数。

如果你更偏好扩展函数，那么asSuspendNoopFn 函数的参数 instance，就传对应的Receiver实例即可