Android Studio中不能使用棒棒糖特定的类 [英] Can't use Lollipop specific classes in Android Studio

问题描述

我有一个 minSdk 21 项目，棒棒堂问题的具体类。
这是我的 gradle.build

I'm having problems with Lollipop specific classes in a minSdk 21 project. This is my gradle.build

android {
compileSdkVersion 21
buildToolsVersion "21.1.0"

defaultConfig {
    applicationId "com.mypackage"
    minSdkVersion 21
    targetSdkVersion 21
    versionCode 1
    versionName "1.0"
}

当我尝试使用 UsageStatsManager 我从<$ C $一个'无法解析符号UsageStatsManager 错误C> Android的工作室。
或者，如果我使用 Context.JOB_SCHEDULER_SERVICE / Context.USAGE_STATS_SERVICE 常量是找不到​​的。

When I try to use UsageStatsManager I get a 'Cannot resolve symbol UsageStatsManager' error from Android Studio. Or if I use Context.JOB_SCHEDULER_SERVICE/Context.USAGE_STATS_SERVICE the constant isn't found.

这是一个例子类，它给了我这些错误。

This is an example class that gives me these errors.

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.app.usage.UsageStatsManager;
import android.app.job.JobScheduler;

public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    UsageStatsManager mUsageStatsManager = (UsageStatsManager) getSystemService(Context.USAGE_STATS_SERVICE);
    JobScheduler mJobScheduler = (JobScheduler) getSystemService(Context.JOB_SCHEDULER_SERVICE);
}

在这种情况下，即使是导入为 UsageStatsManager 失败，出现错误'无法解析符号UsageStatsManager，而的jobscheduler 被找到（但因为我有我可以不使用它没有 Context.JOB_SCHEDULER_SERVICE ）

In this case even the import for UsageStatsManager fails with the error 'Cannot resolve symbol UsageStatsManager', while the JobScheduler is found (but I can't use it because I have no Context.JOB_SCHEDULER_SERVICE)

我已经下载从 SDK管理器，我都在<$ C $ 的android-21 平台C>源和 SDK 。

I've downloaded android-21 platform from the SDK Manager, I have both the source and the SDK.

我缺少的东西吗？

推荐答案

来自旧安装的Andr​​oid工作室的东西是造成问题，所以我也跟着的这个答案并删除缓存。现在它的工作原理。

Something from an old installation of Android Studio was causing problems, so I followed this answer and deleted the caches. It now works.

这篇关于Android Studio中不能使用棒棒糖特定的类的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！