android - 为什么这段代码无法正常运行？

Question

package com.example.archer.mobliesafe;

import android.content.pm.IPackageStatsObserver;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageStats;
import android.graphics.drawable.Drawable;
import android.os.Handler;
import android.os.Message;
import android.os.RemoteException;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.format.Formatter;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import butterknife.Bind;

import static android.R.id.list;
import static android.view.View.inflate;

public class CleanCacheActivity extends AppCompatActivity {

private PackageManager packageManager;
private List<CacheInfo> cacheInfos;
private ListView listView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    initUI();
}

private void initUI() {

    setContentView(R.layout.activity_clean_cache);

    listView = (ListView) findViewById(R.id.list_view_cache);
    cacheInfos = new ArrayList<>();
    packageManager = getPackageManager();

//当我们去拿数据的时候，面对的是一个耗时的操作，因此需要开启一个子线程

    new Thread(){
        @Override
        public void run() {
            //        packageManager.getPackageSizeInfo();
            List<PackageInfo> installedPackages = packageManager.getInstalledPackages(0);

            for (PackageInfo packageInfo : installedPackages) {
                getCacheSize(packageInfo);
            }

            handler.sendEmptyMessage(0);

        }

    }.start();

}

private Handler handler=new Handler(){
    @Override
    public void handleMessage(Message msg) {
        CacheAdapter MyAdapter=new CacheAdapter();
        listView.setAdapter(MyAdapter);
    }
};

//写一个适配器用于适配数据
private class CacheAdapter extends BaseAdapter{

    /**
     * How many items are in the data set represented by this Adapter.
     *
     * @return Count of items.
     */
    @Override
    public int getCount() {
        return cacheInfos.size();
    }

    /**
     * Get the data item associated with the specified position in the data set.
     *
     * @param position Position of the item whose data we want within the adapter's
     *                 data set.
     * @return The data at the specified position.
     */
    @Override
    public Object getItem(int position) {
        return cacheInfos.get(position);
    }

    /**
     * Get the row id associated with the specified position in the list.
     *
     * @param position The position of the item within the adapter's data set whose row id we want.
     * @return The id of the item at the specified position.
     */
    @Override
    public long getItemId(int position) {
        return position;
    }

    /**
     * Get a View that displays the data at the specified position in the data set. You can either
     * create a View manually or inflate it from an XML layout file. When the View is inflated, the
     * parent View (GridView, ListView...) will apply default layout parameters unless you use
     * {@link LayoutInflater#inflate(int, ViewGroup, boolean)}
     * to specify a root view and to prevent attachment to the root.
     *
     * @param position    The position of the item within the adapter's data set of the item whose view
     *                    we want.
     * @param convertView The old view to reuse, if possible. Note: You should check that this view
     *                    is non-null and of an appropriate type before using. If it is not possible to convert
     *                    this view to display the correct data, this method can create a new view.
     *                    Heterogeneous lists can specify their number of view types, so that this View is
     *                    always of the right type (see {@link #getViewTypeCount()} and
     *                    {@link #getItemViewType(int)}).
     * @param parent      The parent that this view will eventually be attached to
     * @return A View corresponding to the data at the specified position.
     */
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        //设置缓存，提高效率
        ViewHolder  holder ;
        View view;
        if (convertView==null){
            //一定要初始化
            view = View.inflate(CleanCacheActivity.this, R.layout.item_clean_cache, null);
            System.out.println("======================================================");
            System.out.println("======================================================");
            System.out.println("======================================================");
            System.out.println("======================================================");
            System.out.println("======================================================");
            holder = new ViewHolder();
            holder.imageView= (ImageView) view.findViewById(R.id.iv_cache_icon);
            holder.tv_cache_size= (TextView) view.findViewById(R.id.tv_cache_size);
            holder.tv_cache_name= (TextView) view.findViewById(R.id.tv_cache_name);

            view.setTag(holder);

        }else {
            //通过tag找到缓存布局
            view =convertView;
            holder= (ViewHolder) view.getTag();

        }

        holder.imageView.setImageDrawable(cacheInfos.get(position).icon);
        holder.tv_cache_name.setText(cacheInfos.get(position).AppName);
        holder.tv_cache_size.setText("缓存："+cacheInfos.get(position).cacheSize);
        return view;
    }

}

private void getCacheSize(PackageInfo  packageInfo) {

    try {

// Class<?> clazz = getClassLoader().loadClass("packageManager");

        //通过反射获取到当前的方法
        Method method = PackageManager.class.getDeclaredMethod("getPackageSizeInfo", String.class,IPackageStatsObserver.class);

        method.invoke(packageManager,packageInfo.applicationInfo.packageName,new  MyIPackageStatsObserver(packageInfo));

    } catch (Exception e) {
        e.printStackTrace();
    }
}

private class  MyIPackageStatsObserver extends  IPackageStatsObserver.Stub{

    private  PackageInfo packageInfo;

    MyIPackageStatsObserver(PackageInfo packageInfo) {
        this.packageInfo=packageInfo;
    }

    @Override
    public void onGetStatsCompleted(PackageStats pStats, boolean succeeded) throws RemoteException {

        //获取到当前手机应用大小
        long cacheSize = pStats.cacheSize;
        //判断是否有缓存
        if (cacheSize>0){

            System.out.println("当前应用的名字："+packageInfo.applicationInfo.loadLabel(packageManager)+
                    " 缓存的大小： "+cacheSize);

            CacheInfo cacheInfo = new CacheInfo();
            Drawable icon= packageInfo.applicationInfo.loadIcon(packageManager);
            cacheInfo.icon= icon;

            String appName= packageInfo.applicationInfo.loadLabel(packageManager).toString();
            cacheInfo.AppName = appName;

            cacheInfo.cacheSize=cacheSize;

            cacheInfos.add(cacheInfo);
        }

    }
}

//封装成一个对象

static  class CacheInfo{
    Drawable icon;
    long cacheSize;
    String AppName;

}

static  class ViewHolder{
    ImageView imageView;
    TextView tv_cache_name;
    TextView tv_cache_size;

}

}

Answer 1

First determine whether it cannot run or an error is thrown. Please fill in the error content for the latter

Answer 2

Debug to see if there is any data in your list

Answer 3

1. First standardize the code structure.

2. If it cannot run normally, is it because an exception is thrown during runtime or the result cannot be displayed correctly?