android - 无法导入 android.support.v7 (appcompat) - 未解析的库

Question

我尝试将此支持库导入到我的项目中，但无法使其工作。

首先我找不到它。当我点击“依赖项”选项卡上的 + 按钮并搜索它时。我找到了 android.support.v4 但我也需要 v7。 我在某处读到该库可能已被弃用。

所以在我的代码中它无法导入 android.support.v7.widget.ShareActionProvider v7 呈红色，因为无法解析。 我按照如何添加库的指示进行操作。但仍然无法解决问题。我执行了正常步骤，如清理、同步 gradle 文件、使链接无效等...

这是我在 mainactivity 中的一些代码

    import android.content.Intent
    import android.os.Bundle
    import android.support.v4.view.MenuItemCompat
    import android.view.Menu
    import android.view.MenuItem
    //import androidx.appcompat.widget.ShareActionProvider
    import androidx.appcompat.widget.Toolbar

    //import androidx.core.view.MenuItemCompat
    //import android.support.v4.view.MenuItemCompat
    //import androidx.core.view.MenuItemCompat.getActionProvider

    import android.support.v7.app.AppCompatActivity
    import android.support.v7.widget.ShareActionProvider
    //import android.widget.ShareActionProvider



    class MainActivity : AppCompatActivity() {
        private var shareActionProvider : ShareActionProvider? = null

    import android.content.Intent
    import android.os.Bundle
    import android.support.v4.view.MenuItemCompat
    import android.view.Menu
    import android.view.MenuItem
    //import androidx.appcompat.widget.ShareActionProvider
    import androidx.appcompat.widget.Toolbar

    //import androidx.core.view.MenuItemCompat
    //import android.support.v4.view.MenuItemCompat
    //import androidx.core.view.MenuItemCompat.getActionProvider

    import android.support.v7.app.AppCompatActivity
    import android.support.v7.widget.ShareActionProvider
    //import android.widget.ShareActionProvider


    class MainActivity : AppCompatActivity() {
        private var shareActionProvider : ShareActionProvider? = null

        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            setContentView(R.layout.activity_main)
            val toolbar = findViewById(R.id.toolbar) as Toolbar
            setSupportActionBar(toolbar)
        }

        override fun onCreateOptionsMenu(menu : Menu): Boolean {
            getMenuInflater().inflate(R.menu.menu_main, menu)
            val menuItem = menu.findItem(R.id.action_share) as MenuItem
            shareActionProvider = MenuItemCompat.getActionProvider(menuItem) as ShareActionProvider
            setShareActionIntent("Want to join me for pizza?")
            return super.onCreateOptionsMenu(menu)
        }

        private fun setShareActionIntent(text : String) {
            val intent = Intent(Intent.ACTION_SEND)
            intent.type = "text/plain"
            intent.putExtra(Intent.EXTRA_TEXT, text)
            shareActionProvider!!.setShareIntent(intent)
        }

        override fun onOptionsItemSelected(item : MenuItem) : Boolean {
            when(item.itemId) {
                R.id.action_create_order -> {
                    val intent = Intent(this, OrderActivity::class.java)
                    startActivity(intent)
                    return true
                }
                else -> return super.onOptionsItemSelected(item)
            }
}
}

这是我的 gradle.build 文件

 // Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    ext.kotlin_version = '1.2.71'
    repositories {
        google()
        jcenter()
        maven { url '../pluginrepo' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.0-beta05'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

这是我的应用程序 (build.gradle) 文件

apply plugin: 'com.android.application'

apply plugin: 'kotlin-android'

apply plugin: 'kotlin-android-extensions'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.gandalf.bitsandpizza"
        minSdkVersion 19
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'androidx.constraintlayout:constraintlayout:1.1.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.1.0-alpha3'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha3'
    //    implementation 'com.android.support:support-core-utils:27.0.0'
    implementation 'com.google.android:support-v4:r7'
    implementation 'com.android.support:appcompat-v7:28.0.+'
    //    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.android.support:support-core-utils:28.0.+'
}

这是基于答案中建议的重构。

问题现已解决。这是应用程序中更新的 gradle.build 文件

apply plugin: 'com.android.application'

apply plugin: 'kotlin-android'

apply plugin: 'kotlin-android-extensions'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.some.name"
        minSdkVersion 19
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    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'
}

Answer 1

So in my code it can't import android.support.v7.widget.ShareActionProvider The v7 is in Red because, it can't be resolved

我希望这是您代码中的唯一问题。您已添加:

implementation 'com.google.android:support-v4:r7'
implementation 'com.android.support:appcompat-v7:28.0.+' // Use specific version like 28.0.0 in future for this

指的是v4和v7AppCompat但是你的Toolbar和测试+ConstraintLayout 正在使用 AndroidX 依赖项。即使对我来说，这实际上也很奇怪和令人困惑!

使用ShareActionProvider这是通过 AppCompat 提供的，您需要先确保您的应用是否已迁移到 AndroidX!

我相信发生这种情况是因为您的项目似乎已迁移到 AndroidX，这会混淆 IDE 使用 AppCompat 或 AndroidX .

简单地说，如果您尝试使用 V7 依赖项，请转到重构，选择迁移到 AppCompat。