在Sdk版本28中找不到AppCompat活动库

Question

我正在用SDK 28创建一个新的android项目，当项目完成创建时，我在MainActivity中出现了一个错误。

我尝试了一些方法：

清洁项目

清理Android Studio缓存

清理Gradle缓存

重新安装的 IDE

文件-

删除 .idea 文件夹

重新启动Android Studio。

Android Studio关于：

Android Studio 3.3.2
Build #AI-182.5107.16.33.5314842, built on February 15, 2019
JRE: 1.8.0_152-release-1248-b01 amd64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
Windows 10 10.0

build.gradle(模块:应用程序)

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.israteneda.myapplicationtest2"
        minSdkVersion 15
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

MainActivity.java

package com.israteneda.myapplicationtest2;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

显示的错误是：

Android resource linking failed
error: resource style/Theme.AppCompat.Light.DarkActionBar (aka com.israteneda.horariu:style/Theme.AppCompat.Light.DarkActionBar) not found.
D:\israt\android_apps\HorariU\app\build\intermediates\incremental\mergeDebugResources\merged.dir\values\values.xml:173: error: style attribute 'attr/colorPrimary (aka com.israteneda.horariu:attr/colorPrimary)' not found.
D:\israt\android_apps\HorariU\app\build\intermediates\incremental\mergeDebugResources\merged.dir\values\values.xml:174: error: style attribute 'attr/colorPrimaryDark (aka com.israteneda.horariu:attr/colorPrimaryDark)' not found.
D:\israt\android_apps\HorariU\app\build\intermediates\incremental\mergeDebugResources\merged.dir\values\values.xml:175: error: style attribute 'attr/colorAccent (aka com.israteneda.horariu:attr/colorAccent)' not found.
error: failed linking references.

当我将 SDK 更改为 27 时，主活动有效。

build.gradle(模块:应用程序)

apply plugin: 'com.android.application'

android {
    compileSdkVersion 27
    defaultConfig {
        applicationId "com.israteneda.horariu"
        minSdkVersion 15
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:27.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

MainActivity.java

package com.israteneda.myapplicationtest2;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

也适用于androidx库。

build.gradle(模块:应用程序)

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.israteneda.myapplicationtest"
        minSdkVersion 15
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.0.0-beta01'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.1.0-alpha4'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha4'
}

维护活动.java

package com.israteneda.myapplicationtest;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

我希望创建一个没有问题的Android项目，但实际输出是 MainActivity 上的 AppCompatActivity 错误。为什么会出现此问题？

Answer 1

通过更新新版本的android studio 3.4解决了该问题，而无需导入先前版本的设置。

Answer 2

1.转到项目目录（或项目视图）

2.查找并打开. ide目录

3.删除缓存和库目录

4.使缓存失效/重新启动

Answer 3

我得到了同样的问题，并通过更新Android Studio解决了它