获取Android 6.0.1的前台应用。UsageStatsManager.queryusagestats在版本6.0.1中返回空列表

import android.app.usage.UsageStats;
import android.app.usage.UsageStatsManager;
import android.content.Context;

import java.util.Calendar;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private UsageStatsManager usageStatsManager;

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

        // 获取UsageStatsManager实例
        usageStatsManager = (UsageStatsManager) getSystemService(Context.USAGE_STATS_SERVICE);

        // 获取当前时间
        Calendar calendar = Calendar.getInstance();
        long endTime = calendar.getTimeInMillis();
        calendar.add(Calendar.DAY_OF_WEEK, -1);
        long startTime = calendar.getTimeInMillis();

        // 查询应用使用情况
        List<UsageStats> usageStatsList = usageStatsManager.queryUsageStats(UsageStatsManager.INTERVAL_DAILY, startTime, endTime);

        if (usageStatsList != null && !usageStatsList.isEmpty()) {
            // 遍历应用使用情况列表
            for (UsageStats usageStats : usageStatsList) {
                // 获取前台应用包名
                String packageName = usageStats.getPackageName();
                // 获取前台应用使用时间
                long totalTimeInForeground = usageStats.getTotalTimeInForeground();

                // 在这里可以对获取到的前台应用信息进行处理
                // ...

                Log.d("UsageStats", "Package Name: " + packageName + ", Total Time in Foreground: " + totalTimeInForeground);
            }
        }
    }
}