毕业设计：HomeFragment

Posted 2020-09-08 学海无涯，回头是岸

一、主要思路

      主要是通过ListView实现。

      考虑到以后会添加长按修改功能，所以好几个地方都是用的FramLayout，而且CheckBox初始状态是被隐藏的。给ListView添加OnItemClickedListener，在识别点击的Item是文件夹时做出响应，把ListView的资源来源改成该文件夹。同时顶部的TextView也要修改成对应文件夹目录。

      目前我没有对返回键设置监听器，所以返回上一级菜单是通过顶部的按钮实现的。在根目录下该按钮隐藏，等到进入下一级目录的时候按钮就会显示出来。

二、FileBean

      FileBean是文件/文件夹的抽象类，包含文件所需的一些必要属性。

package com.example.vcloud_3_25.bean;

import java.util.Date;

/*
 * 包含文件的通用属性和方法
 */
public class FileBean {
    public static final int ROOT = 0x7fffffff;
    private int id;
    private int pId;
    private String name;
    private String type;
    private String info;
    private Date date;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public int getpId() {
        return pId;
    }

    public void setpId(int pId) {
        this.pId = pId;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public String getInfo() {
        return info;
    }

    public void setInfo(String info) {
        this.info = info;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    public FileBean(int id, int pId, String name, String type, Date date) {
        super();
        this.id = id;
        this.pId = pId;
        this.name = name;
        this.type = type;
        this.date = date;
    }

}

三、FileHelper

      我是这样考虑的，要把一个目录下的所有文件加载出来，就需要设置pId-->FileBeanList的对应关系，所以最方便的就是通过Map实现。在编写过程中程序提示我可以使用SparseArray来代替HashMap，可以提升效率，所以我就使用SparseArray来实现了。至于初始数据如何得到我还没有考虑，所以就在构造函数里自定义了一些数据，这些FileBean是没有预先排好序列，也不具备我预想的pId-->FileBeanList结构，所以我在FileHelper这个类中编写了基础的排序以及结构化的函数。

package com.example.vcloud_3_25.utils;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.List;
import android.util.SparseArray;

import com.example.vcloud_3_25.bean.FileBean;

public class FileHelper {
    private List<FileBean> mList;

    public FileHelper(){
        FileBean f1 = new FileBean(1, FileBean.ROOT, "folder1", "folder",
                new Date());
        FileBean f2 = new FileBean(2, FileBean.ROOT, "avi1", "avi", new Date());
        FileBean f3 = new FileBean(3, FileBean.ROOT, "folder2", "folder",
                new Date());
        FileBean f4 = new FileBean(4, 1, "txt1", "txt", new Date());
        FileBean f5 = new FileBean(5, 1, "txt2", "txt", new Date());
        FileBean f6 = new FileBean(6, 1, "txt3", "txt", new Date());
        FileBean f7 = new FileBean(7, 1, "txt4", "txt", new Date());
        FileBean f8 = new FileBean(8, FileBean.ROOT, "txt5", "txt", new Date());
        FileBean f9 = new FileBean(9, FileBean.ROOT, "txt6", "txt", new Date());

        mList = new ArrayList<FileBean>();
        mList.add(f1);
        mList.add(f2);
        mList.add(f3);
        mList.add(f4);
        mList.add(f5);
        mList.add(f6);
        mList.add(f7);
        mList.add(f8);
        mList.add(f9);
    }
    public SparseArray<List<FileBean>> getResMap() {
        

        Collections.sort(mList, new MyComparator());
        SparseArray<List<FileBean>> map = new SparseArray<List<FileBean>>();

        for (FileBean f : mList) {
            if (getChildren(f.getId()) != null)
                map.put(f.getId(), getChildren(f.getId()));
            
            else 
                map.put(f.getId(), new ArrayList());
        }

        return map;
    }

    public List<FileBean> getChildren(int id) {
        List<FileBean> list = new ArrayList<FileBean>();
        for (FileBean f : mList) {
            if (f.getpId() == id)
                list.add(f);
        }
        Collections.sort(list, new MyComparator());
        return list;
    }

    class MyComparator implements Comparator<FileBean> {

        @Override
        public int compare(FileBean f1, FileBean f2) {
            if (f1.getType() == f2.getType()) {
                return f1.getName().compareTo(f2.getName());
            } else if (f1.getType().equals("folder")) {
                return -1;
            } else if (f2.getType().equals("folder")) {
                return 1;
            }
            return f1.getType().compareTo(f2.getType());
        }

    }
}

 

四、HomeFragment

      这个就稍微臃肿了一点，我在考虑后期重构这段代码。

      有一个需要注意的点，就是如何刷新ListView的问题。这在网络上能很容易的找到答案，就是先clear一下List，然后用addAll函数添加数据，最后使用Adapter的notifyDataSetChanged()方法更新数据。因为常用所以我把它抽取为了一个函数。

package com.example.vcloud_3_25;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.app.Fragment;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v4.widget.SwipeRefreshLayout.OnRefreshListener;
import android.util.Log;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ImageButton;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;

import com.example.vcloud_3_25.bean.FileBean;
import com.example.vcloud_3_25.utils.FileHelper;

public class HomeFragment extends Fragment {

    private ListView mListView = null;
    private FileHelper mFileHelper = null;

    // Map，每一个int型id对应一个FileBean列表。用于展现文件夹包含关系。
    private SparseArray<List<FileBean>> mResMap = null;
    private List<Map<String, Object>> mResList;
    private int recentPid;
    private View view;
    private SwipeRefreshLayout refresh;
    private List<Integer> mDirList;
    private List<String> mDirStrList;
    private SimpleAdapter adapter;
    private String mDirString;
    private TextView mDirTextView;
    private ImageButton mBackButton;
    private ImageButton mAddButton;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        initView(inflater, container);
        initData();
        return view;
    }

    private void initData() {
        mFileHelper = new FileHelper();
        mResMap = mFileHelper.getResMap();
        recentPid = FileBean.ROOT;
        mResList = getResList(recentPid);
        mDirList = new ArrayList<Integer>();
        mDirStrList = new ArrayList<String>();
        mDirList.add(FileBean.ROOT);
        mDirStrList.add("root");
        mDirString = "root/";
        
        mBackButton.setVisibility(view.INVISIBLE);
        
        adapter = new SimpleAdapter(this.getActivity(), mResList,
                R.layout.file_item, new String[] { "fileName", "fileDate",
                        "fileImag", "fileCheckBox" }, new int[] {
                        R.id.item_name, R.id.item_date, R.id.file_imag,
                        R.id.file_checkbox });
        mListView.setAdapter(adapter);

        mListView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View item,
                    int position, long id) {

                ListView lv = (ListView) parent;
                @SuppressWarnings("unchecked")
                HashMap<String, Object> mMap = (HashMap<String, Object>) lv
                        .getItemAtPosition(position);
                String type = (String) mMap.get("fileType");

                // 如果点击的是文件夹，则打开该文件夹，并且修改当前目录，修改目录列表；否则不作反应。

                if (type.equals("folder")) {
                    recentPid = (Integer) mMap.get("fileId");
                    mDirList.add(recentPid);
                    mDirStrList.add((String) mMap.get("fileName"));
                    setDirString();
                    refreshListView();
                }
                
                mBackButton.setVisibility(view.VISIBLE);

            }
        });

        refresh.setOnRefreshListener(new OnRefreshListener() {
            @Override
            public void onRefresh() {
                new Handler().postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        refreshListView();
                        refresh.setRefreshing(false);
                    }
                }, 1000);
            }
        });
        
        mBackButton.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View view) {
                mDirStrList.remove(mDirStrList.size()-1);
                mDirList.remove(mDirList.size()-1);
                recentPid = mDirList.get(mDirList.size()-1);
                setDirString();
                refreshListView();
                
                if(mDirList.size()==1)
                    mBackButton.setVisibility(view.INVISIBLE);
            }
        });
    }

    private void initView(LayoutInflater inflater, ViewGroup container) {
        view = inflater.inflate(R.layout.main_tab_1, container, false);
        mListView = (ListView) view.findViewById(R.id.folder_content_list);
        refresh = (SwipeRefreshLayout) view
                .findViewById(R.id.id_refresh_layout);
        mDirTextView = (TextView) view.findViewById(R.id.folder_name);
        mBackButton = (ImageButton) view.findViewById(R.id.id_back_button);
        mAddButton = (ImageButton) view.findViewById(R.id.upload_imag);
    }

    // 该List用于和ListView绑定
    @SuppressLint("SimpleDateFormat")
    private List<Map<String, Object>> getResList(int id) {
        List<Map<String, Object>> mMaps = new ArrayList<Map<String, Object>>();
        Map<String, Object> map;
        for (FileBean f : mFileHelper.getChildren(id)) {

            SimpleDateFormat formatter = new SimpleDateFormat(
                    "yyyy-MM-dd HH:mm:ss");

            map = new HashMap<String, Object>();
            map.put("fileName", f.getName());
            map.put("fileDate", formatter.format(new Date()));
            map.put("fileImag", getFileImag(f.getType()));
            map.put("fileId", f.getId());
            map.put("fileCheckBox", R.id.file_checkbox);
            map.put("fileType", f.getType());

            mMaps.add(map);
            Log.d("map.put", f.getName());
        }
        return mMaps;
    }

    // 根据String类型的文件类型找出对应的图片ID
    private int getFileImag(String type) {
        if (type.equals("avi"))
            return R.drawable.avi;
        else if (type.equals("doc"))
            return R.drawable.doc;
        else if (type.equals("exe"))
            return R.drawable.exe;
        else if (type.equals("fla"))
            return R.drawable.fla;
        else if (type.equals("folder"))
            return R.drawable.folder;
        else if (type.equals("html"))
            return R.drawable.html;
        else if (type.equals("mp3"))
            return R.drawable.mp3;
        else if (type.equals("mp4"))
            return R.drawable.mp4;
        else if (type.equals("pdf"))
            return R.drawable.pdf;
        else if (type.equals("png"))
            return R.drawable.png;
        else if (type.equals("ppt"))
            return R.drawable.ppt;
        else if (type.equals("xml"))
            return R.drawable.xml;
        else if (type.equals("zip"))
            return R.drawable.zip;
        return R.drawable.other;
    }
    
    private void setDirString(){
        String str = "";
        for(String s:mDirStrList){
            str = str+s+"/";
        }
        mDirTextView.setText(str);
    }
    private void refreshListView(){
        mResList.clear();
        mResList.addAll(getResList(recentPid));
        adapter.notifyDataSetChanged();
    }
}