获取棒棒糖中运行任务的baseActivity

import android.app.ActivityManager;
import android.app.ActivityManager.RunningTaskInfo;
import android.content.ComponentName;
import android.content.Context;

public String getBaseActivity(Context context) {
    ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    List<RunningTaskInfo> taskInfo = am.getRunningTasks(1);
    ComponentName componentInfo = taskInfo.get(0).baseActivity;
    return componentInfo.getClassName();
}

import android.app.usage.UsageStats;
import android.app.usage.UsageStatsManager;
import android.content.Context;
import java.util.List;
import java.util.SortedMap;
import java.util.TreeMap;

public String getBaseActivityUsingUsageStats(Context context) {
    long time = System.currentTimeMillis();
    UsageStatsManager usageStatsManager = (UsageStatsManager) context.getSystemService(Context.USAGE_STATS_SERVICE);
    List<UsageStats> stats = usageStatsManager.queryUsageStats(UsageStatsManager.INTERVAL_DAILY, time - 1000 * 10, time);

    if (stats != null) {
        SortedMap<Long, UsageStats> sortedMap = new TreeMap<>();
        for (UsageStats usageStats : stats) {
            sortedMap.put(usageStats.getLastTimeUsed(), usageStats);
        }
        if (!sortedMap.isEmpty()) {
            return sortedMap.get(sortedMap.lastKey()).getPackageName();
        }
    }
    return null;
}