小编Nai*_*oni的帖子

我写一个简单的优惠券应用，但最近我更新了一些依赖和我Fragment 没有让我return null

错误照片：

package com.szakes1.makdolannative.adapters

import androidx.fragment.app.Fragment
import androidx.fragment.app.FragmentManager
import androidx.fragment.app.FragmentStatePagerAdapter
import com.szakes1.makdolannative.R
import com.szakes1.makdolannative.fragments.CouponFragment
import com.szakes1.makdolannative.fragments.HomeFragment

class ViewPagerAdapter(fm: FragmentManager, private val numberOfFrags: Int) : FragmentStatePagerAdapter(fm, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) {
    override fun getItem(position: Int): Fragment? {
        when (position) {
            0 -> return HomeFragment()
            1 -> return CouponFragment(R.drawable.coupon_hamburger)
            2 -> return CouponFragment(R.drawable.coupon_icecream)
            3 -> return CouponFragment(R.drawable.coupon_cheeseburger)
            4 -> return CouponFragment(R.drawable.coupon_fries)
        }
        return null
    }

    override fun getCount(): Int {
        return numberOfFrags
    }

    override fun getPageTitle(position: Int): CharSequence? {
        when …

我最近开始使用firebase，并遵循官方指南，为项目添加了一些依赖项才能使用它。这是我添加到新创建的项目中的依赖项：

apply plugin: 'com.google.gms.google-services'
implementation "com.google.firebase:firebase-core:$firebaseCoreVersion"
implementation "com.google.firebase:firebase-auth:$firebaseAuthVersion"


buildscript {
    ...
    ext{
        firebaseCoreVersion='17.0.0'
        firebaseAuthVersion='18.0.0'
    }
}

同步我的项目后，我得到了一个非常糟糕的警告。

WARNING: API 'variant.getMergeResources()' is obsolete 
and has been replaced with 'variant.getMergeResourcesProvider()'.
It will be removed at the end of 2019.

所以，我在gradle.properties中添加了以下代码行，以查看问题所在。

android.debug.obsoleteApi=true

不幸的是，如果我做错了什么，或者我可以做些什么，我从堆栈跟踪中无法理解。

在整个堆栈跟踪下，请先感谢您可以给我的任何评论或答案。

REASON: It is currently called from the following trace:
java.lang.Thread.getStackTrace(Thread.java:1556)
com.android.build.gradle.internal.errors.DeprecationReporterImpl.reportDeprecatedApi(DeprecationReporterImpl.kt:79)
com.android.build.gradle.internal.api.BaseVariantImpl.getMergeResources(BaseVariantImpl.java:349)
com.android.build.gradle.internal.api.ApplicationVariantImpl_Decorated.getMergeResources(null:-1)
sun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethodAccessorImpl.java:-2)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:104)
groovy.lang.MetaBeanProperty.getProperty(MetaBeanProperty.java:59)
org.gradle.internal.metaobject.BeanDynamicObject$MetaClassAdapter.getProperty(BeanDynamicObject.java:228)
org.gradle.internal.metaobject.BeanDynamicObject.tryGetProperty(BeanDynamicObject.java:171)
org.gradle.internal.metaobject.CompositeDynamicObject.tryGetProperty(CompositeDynamicObject.java:55)
org.gradle.internal.metaobject.AbstractDynamicObject.getProperty(AbstractDynamicObject.java:59)
com.android.build.gradle.internal.api.ApplicationVariantImpl_Decorated.getProperty(null:-1)
org.codehaus.groovy.runtime.callsite.PogoGetPropertySite.getProperty(PogoGetPropertySite.java:49)
org.codehaus.groovy.runtime.callsite.AbstractCallSite.callGetProperty(AbstractCallSite.java:298)
com.google.gms.googleservices.GoogleServicesPlugin.handleVariant(GoogleServicesPlugin.groovy:164)
sun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethodAccessorImpl.java:-2)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:104)
groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:326)
org.gradle.internal.metaobject.BeanDynamicObject$MetaClassAdapter.invokeMethod(BeanDynamicObject.java:479)
org.gradle.internal.metaobject.BeanDynamicObject.tryInvokeMethod(BeanDynamicObject.java:191)
org.gradle.internal.metaobject.ConfigureDelegate.invokeMethod(ConfigureDelegate.java:78)
org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeOnDelegationObjects(ClosureMetaClass.java:398)
org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:338)
org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:68) …