AndroidTXT阅读器的实现（—）扫描sd卡或选择文件路径添加文件到listview及listview的多选删除

不知怎么突然有了想写一个txt阅读器的想法 ……目前只实现了一小部分功能，并且参考了网上很多大神的代码，受益匪浅！！~

目前实现的功能：

        1.（1）首次打开阅读器时，会弹出选择对话框，可以选择扫描sd卡方式，扫描出sd卡上的所有txt文件并进行简单的筛选（>50KB）之后，得到的文件将被显示在ListView中；   

           （2）若选择了通过路径添加，则会弹出路径选择的Activity，点击确定后选择的txt文件将会出现在ListView的最后；

           （3）若选择了稍后手动添加，则稍候可点击界面右上角加号弹出该选择对话框。

        2.长按ListView中的item，则会进入多选删除模式。

嗯哼……开始贴代码了……

主activity的布局文件就不贴了 。。一个ListView。。。一个listitem。。。贴一下menu：book_list.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:id="@+id/action_addingbooks"
        android:icon="@android:drawable/ic_menu_add"
        android:orderInCategory="500"
        android:showAsAction="ifRoom"
        android:title="添加书籍"/>

</menu>

实现右上角的加号，点击弹出添加书籍对话框功能。

然后是BookListActivity.class

package com.ldgforever.jianreader;

import android.app.*;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.*;
import android.util.Log;
import android.view.*;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.AbsListView.MultiChoiceModeListener;
import com.ldgforever.jianreader.R;
import com.ldgforever.savedata.savedataListMap;
import java.io.File;
import java.util.*;

public class BookListActivity extends Activity {

	private static List<String> file_name;
	private static List<String> file_txt_path;
	private MyBookAdapter adapter;
	private File file;
	private List<Map<String, String>> listItems;
	private MultiModeCallback mCallback;
	private String mExternalStoragePath;
	private Handler mHandler;
	private ListView mListView;
	private ProgressDialog mProgressDialog;

	/**
	 * 接收返回的路径
	 */
	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		Log.d("com.ldgforever.jianreader", "receivingPath");
		if (data != null) {
			Log.d("com.ldgforever.jianreader", "onActivityResult");
			String mPath = data.getStringExtra("file");
			File pathFile = new File(mPath);
			Map<String, String> pathMap = new HashMap<String, String>();
			if (pathFile.exists()) {
				if (pathFile.getName().endsWith(".txt")) {
					pathMap.put("Name", pathFile.getName());
					pathMap.put("Path", pathFile.getPath());
					listItems.add(pathMap);
					savedataListMap.saveInfo(BookListActivity.this, "ListMap", listItems);
					ShowTxtFilesInList(listItems);
				} else {
					Toast.makeText(BookListActivity.this, "请选择一个txt文件！", 0).show();
					;
				}
			}
		}
	}

	@Override
	protected void onCreate(Bundle bundle) {
		super.onCreate(bundle);
		setContentView(R.layout.activity_book_list);

		mProgressDialog = new ProgressDialog(BookListActivity.this);
		mProgressDialog.setCancelable(false);
		mProgressDialog.setMessage("正在搜索书籍，请稍候 ……");

		mExternalStoragePath = Environment.getExternalStorageDirectory().toString();
		file = new File(mExternalStoragePath);

		file_name = new ArrayList<String>();
		file_txt_path = new ArrayList<String>();
		listItems = new ArrayList<Map<String, String>>();

		listItems = savedataListMap.getInfo(BookListActivity.this, "ListMap");
		if (listItems.isEmpty()) {
			BookAddingDialog();
		} else {
			ShowTxtFilesInList(listItems);
		}

		mHandler = new Handler() {
			public void handleMessage(Message message) {
				switch (message.what) {
				case 11:
					ShowTxtFilesInList(listItems);
					savedataListMap.saveInfo(BookListActivity.this, "ListMap", listItems);
					if (mProgressDialog.isShowing()) {
						mProgressDialog.dismiss();
						return;
					}
					break;
				case 12:
					ShowTxtFilesInList(listItems);
					savedataListMap.saveInfo(BookListActivity.this, "ListMap", listItems);
					if (mProgressDialog.isShowing()) {
						mProgressDialog.dismiss();
						return;
					}
					break;
				default:
					break;
				}
				return;
			}
		};
	}

	/**
	 * 书籍添加对话框
	 */
	private void BookAddingDialog() {
		android.app.AlertDialog.Builder builder = new android.app.AlertDialog.Builder(this);
		builder.setTitle("请选择添加书籍的方式");
		builder.setPositiveButton("扫描SDCard添加", new android.content.DialogInterface.OnClickListener() {
			public void onClick(DialogInterface dialoginterface, int i) {
				listItems = new ArrayList<Map<String, String>>();
				mProgressDialog.show();
				new Thread() {
					public void run() {
						listFileTxt(file);
						mHandler.sendEmptyMessage(12);
					}
				}.start();
			}
		});
		builder.setNegativeButton("选择路径添加", new android.content.DialogInterface.OnClickListener() {

			public void onClick(DialogInterface dialoginterface, int i) {

				Intent intent = new Intent(BookListActivity.this, MyFileManager.class);
				startActivityForResult(intent, 2);
			}
		});
		builder.setNeutralButton("稍后手动添加", new android.content.DialogInterface.OnClickListener() {

			public void onClick(DialogInterface dialoginterface, int i) {
				dialoginterface.dismiss();
			}

		});
		builder.create().show();
	}

	/**
	 * 将保存在List<Map<String,String>>中的书籍信息显示到ListView中
	 * @param listItems
	 */
	private void ShowTxtFilesInList(List<Map<String, String>> listItems) {
		if (file_name != null) {
			for (int i = 0; i < file_name.size(); i++) {
				HashMap<String, String> hashmap = new HashMap<String, String>();
				hashmap.put("Name", (String) file_name.get(i));
				hashmap.put("Path", (String) file_txt_path.get(i));
				listItems.add(hashmap);
			}
			adapter = new MyBookAdapter(this, listItems);
			mCallback = new MultiModeCallback();
			mListView = (ListView) findViewById(R.id.booklist);
			mListView.setChoiceMode(3); // Multi
			mListView.setMultiChoiceModeListener(mCallback);
			mListView.setAdapter(adapter);
		} else {
			failAddingDialog();
			return;
		}
	}

	/**
	 * 添加书籍失败对话框
	 */
	private void failAddingDialog() {
		android.app.AlertDialog.Builder builder = new android.app.AlertDialog.Builder(this);
		builder.setTitle("添加书籍失败");
		builder.setPositiveButton("确定", new android.content.DialogInterface.OnClickListener() {
			public void onClick(DialogInterface dialoginterface, int i) {
				dialoginterface.dismiss();
			}
		});
	}

	/**
	 * 递归查找SD卡上所有书籍
	 * @param file
	 */
	public static void listFileTxt(File file) {
		File[] files = file.listFiles();

		try {
			for (File f : files) {
				if (!f.isDirectory()) {
					if (f.getName().endsWith(".txt")) {
						long size = f.length();
						if (size > 50 * 1024) {
							file_name.add(f.getName());
							file_txt_path.add(f.getAbsolutePath());
						}
					}
				} else if (f.isDirectory()) {
					listFileTxt(f);
				}
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.book_list, menu);
		return super.onCreateOptionsMenu(menu);
	}

	public boolean onOptionsItemSelected(MenuItem menuitem) {
		switch (menuitem.getItemId()) {
		case R.id.action_addingbooks:
			BookAddingDialog();
			break;

		default:
			break;
		}
		return true;
	}

	private class MultiModeCallback implements MultiChoiceModeListener {

		public boolean onActionItemClicked(ActionMode actionmode, MenuItem menuitem) {
			switch (menuitem.getItemId()) {
			case R.id.menu_delete:
				adapter.deleteSeletcedItems();
				adapter.notifyDataSetChanged();
				actionmode.finish();
				return true;
			default:
				return false;
			}
		}

		public boolean onCreateActionMode(ActionMode actionmode, Menu menu) {
			actionmode.getMenuInflater().inflate(R.menu.book_actionmenu, menu);
			adapter.setItemMultiCheckable(true);
			adapter.notifyDataSetChanged();
			return true;
		}

		public void onDestroyActionMode(ActionMode actionmode) {
			savedataListMap.saveInfo(BookListActivity.this, "ListMap", listItems);
			adapter.setItemMultiCheckable(false);
			adapter.clearSeletedItems();
			adapter.notifyDataSetChanged();
		}

		public void onItemCheckedStateChanged(ActionMode actionmode, int i, long l, boolean flag) {
			if (flag)
				adapter.addSelectedItem(i);
			else
				adapter.cancelSelectedItem(i);
			adapter.notifyDataSetChanged();
			actionmode.invalidate();
		}

		public boolean onPrepareActionMode(ActionMode actionmode, Menu menu) {
			return false;
		}
	}
}

程序里有一定的注释0-0，直接看比较清晰。查找txt文件用的是递归查找文件名末尾为".txt"的文件，如果满足条件就添加到Map<String,String>里。这里还自定义了一个Adapter用以将txt文件更新到ListView上并且应用了ActionMode实现了ListView的多选和删除功能。关于ActionMode的使用参考了以下两篇文章，感谢！

1.http://blog.csdn.net/xyz_lmn/article/details/12754785

2.http://blog.csdn.net/ghost_programmer/article/details/46827933   （强推）

然后就是点击通过路径添加之后通过startForResult打开路径添加的Activity

嚄……贴一下actionmode的menu，里面只有一个删除的按钮

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
  
    <item
        android:id="@+id/menu_delete"
        android:icon="@android:drawable/ic_menu_delete"
        android:showAsAction="ifRoom"
        android:title="删除"/>

</menu>

贴一下自定义的BookAdapter，删除添加item的方法也写在了里面

package com.ldgforever.jianreader;

import android.content.Context;
import android.view.*;
import android.widget.*;
import java.util.*;

import com.ldgforever.jianreader.R;

public class MyBookAdapter extends BaseAdapter {

	private List<Map<String, String>> listItems;
	private static List<Map<String, String>> isSelected;
	private boolean itemMultiCheckable;
	private Context mContext;
	private ViewHolder mViewHolder;

	static class ViewHolder {
		public TextView mBookName;
		public CheckBox mCheckBox;
	}

	public MyBookAdapter(Context context, List<Map<String, String>> listItems) {
		this.mContext = context;
		this.listItems = listItems;
		isSelected = new ArrayList<Map<String, String>>();
	}

	@Override
	public long getItemId(int position) {
		return position;
	}

	@Override
	public int getCount() {
		return listItems.size();
	}

	@Override
	public Object getItem(int i) {
		return listItems.get(i);
	}

	@Override
	public View getView(int i, View view, ViewGroup viewgroup) {
		mViewHolder = new ViewHolder();
		if (view == null) {
			view = LayoutInflater.from(mContext).inflate(R.layout.booklist_item, null);
			mViewHolder.mBookName = (TextView) view.findViewById(R.id.book_name);
			mViewHolder.mCheckBox = (CheckBox) view.findViewById(R.id.mCheckBox);
			view.setTag(mViewHolder);
		} else {
			mViewHolder = (ViewHolder) view.getTag();
		}
		if (itemMultiCheckable) {
			mViewHolder.mCheckBox.setVisibility(View.VISIBLE);
			if (isSelected.contains(listItems.get(i))) {
				mViewHolder.mCheckBox.setChecked(true);
			} else {
				mViewHolder.mCheckBox.setChecked(false);
			}
		} else {
			mViewHolder.mCheckBox.setVisibility(View.GONE);
		}

		mViewHolder.mBookName.setText(listItems.get(i).get("Name"));
		return view;
	}

	public void addSelectedItem(int i) {
		isSelected.add(listItems.get(i));
	}

	public void cancelSelectedItem(int i) {
		isSelected.remove(listItems.get(i));
	}

	public void clearSeletedItems() {
		isSelected = new ArrayList<Map<String, String>>();
	}

	public void deleteSeletcedItems() {
		for (Map<String, String> map : isSelected) {
			listItems.remove(map);
		}
	}

	public void setItemMultiCheckable(boolean flag) {
		itemMultiCheckable = flag;
	}
}

为了每次打开应用不重新扫描txt……需要存储一下存有txt文件信息的List<Map<String,String>>,这里我主要查到了两种方法，1.序列化  2.存为JSON数组形式  然后保存在SharePreference中

1.序列化

package com.ldgforever.jianreader;

import java.io.Serializable;
import java.util.List;
import java.util.Map;

public class SeriallizableList implements Serializable {

	private List<Map<String, String>> listItems;

	public SeriallizableList() {
	}

	public List<Map<String, String>> getListItems() {
		return listItems;
	}

	public void setListItems(List<Map<String, String>> list) {
		listItems = list;
	}
}

2.保存为JSON数组形式

  这里就不贴了0.0 贴出参考的内容相同的博（虽然是在别的网站看见的但是贴站内好像比较友好……？），感觉没有什么改的必要。

http://blog.csdn.net/windowsxp2014/article/details/44620113

然后0.0就到了选择路径添加的部分……首先来看一下布局文件

一个用来显示当前目录路径的TextView，一个ListView列出可供选择的文件，线性布局的最下方是确定和取消两个按钮。这里还应用了Selector来改变点击ListView的item时的背景颜色，为了某种程度上的美观……？通过android：listSelector = "@drawable/mfilelist_view"设置

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FFFFFF"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/tv_path"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5px"
        android:textColor="#436EEE"
        android:textSize="20sp" >
    </TextView>

    <ListView
        android:id="@android:id/list"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="9" 
        android:listSelector="@drawable/mfilelist_view">
    </ListView>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="#FFFFFF"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/btn_yes"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_margin="6dp"
            android:layout_weight="1"
            android:background="#436EEE"
            android:text="确定"
            android:textColor="#FFFFFF" />

        <Button
            android:id="@+id/btn_cancel"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_margin="6dp"
            android:layout_weight="1"
            android:background="#436EEE"
            android:text="取消"
            android:textColor="#FFFFFF" />
    </LinearLayout>

</LinearLayout>

mfilelist_view.xml如下

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >

  <item android:state_selected="true" 
        android:drawable="@color/lightyellow" /> 
        
  <item android:state_focused="true" 
        android:drawable="@color/lightyellow" />
  
  <item android:state_pressed="true" 
        android:drawable="@color/lightyellow" />
    
</selector>

及其应用的color.xml（values文件夹下）

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <color name="white">#ffffff</color>
    <color name="black">#000000</color>
    <color name="lightyellow">#FFEBCD</color>

</resources>

list_item懒得贴了，没有什么图标啥的就是一个光秃秃的TextView。

自定义的Adapter如下

package com.ldgforever.jianreader;

import java.io.File;
import java.util.List;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

public class MyFileAdapter extends BaseAdapter {

	private LayoutInflater mInflater;
	private List<String> items;
	private List<String> paths;

	public MyFileAdapter(Context context, List<String> items, List<String> paths) {
		mInflater = LayoutInflater.from(context);
		this.items = items;
		this.paths = paths;
	}

	public int getCount() {
		return items.size();
	}

	public Object getItem(int position) {
		return items.get(position);
	}

	public long getItemId(int position) {
		return position;
	}

	public View getView(int position, View convertView, ViewGroup parent) {
		ViewHolder holder;

		if (convertView == null) {
			convertView = mInflater.inflate(R.layout.filelist_item, null);
			holder = new ViewHolder();
			holder.mFileTextView = (TextView) convertView.findViewById(R.id.list_text);

			convertView.setTag(holder);
		} else {
			holder = (ViewHolder) convertView.getTag();
		}

		File f = new File(paths.get(position).toString());
		if (items.get(position).toString().equals("b1")) {
			holder.mFileTextView.setText("返回根目录..");
		} else if (items.get(position).toString().equals("b2")) {
			holder.mFileTextView.setText("返回上一层..");
		} else {
			if (f.isDirectory()) {
				holder.mFileTextView.setText("+ "+f.getName());
			} else {
				holder.mFileTextView.setText(f.getName());
			}
		}

		return convertView;
	}

	private class ViewHolder {
		TextView mFileTextView;
	}
}

最后就路径添加的Activity了，若点击的为目录，则用ListView显示当前目录下的所有文件；反之就出现选中，背景颜色改变。点击确定后，将获取的选定的文件路径传回BookListActivity。若点击取消则直接finish掉当前Activity。

package com.ldgforever.jianreader;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class MyFileManager extends ListActivity {

	private List<String> items = null;
	private List<String> paths = null;
	private String rootPath = "/";
	private String curPath = "/";
	private TextView mPath;
	private MyFileAdapter adapter;
	private boolean mItemFlag = false;

	@Override
	protected void onCreate(Bundle bundle) {
		super.onCreate(bundle);
		setContentView(R.layout.activity_fileselect_list);

		mPath = (TextView) findViewById(R.id.tv_path);

		Button buttonConfirm = (Button) findViewById(R.id.btn_yes);
		buttonConfirm.setOnClickListener(new OnClickListener() {

			public void onClick(View v) {
				if (mItemFlag) {
					Intent data = new Intent(MyFileManager.this, BookListActivity.class);
					data.putExtra("file", curPath);
					Log.d("com.ldgforever.jianreader", curPath);
					setResult(2, data);
					finish();
				} else {
					Toast.makeText(MyFileManager.this, "请选择一个txt文件！", 0).show();
				}
			}
		});
		Button buttonCancle = (Button) findViewById(R.id.btn_cancel);
		buttonCancle.setOnClickListener(new OnClickListener() {

			public void onClick(View v) {
				finish();
			}
		});
		getFileDir(rootPath);
	}

	/**
	 * 如果文件是目录，则将目录下的文件显示在listview中
	 * 
	 * @param filePath
	 */
	private void getFileDir(String filePath) {
		mPath.setText(filePath);
		items = new ArrayList<String>();
		paths = new ArrayList<String>();
		File f = new File(filePath);
		adapter = new MyFileAdapter(this, items, paths);
		if (f.isDirectory()) {
			File[] files = f.listFiles();

			if (!filePath.equals(rootPath)) {
				items.add("b1");
				paths.add(rootPath);
				items.add("b2");
				paths.add(f.getParent());
			}

			if (files != null) {
				for (int i = 0; i < files.length; i++) {
					File file = files[i];
					items.add(file.getName());
					paths.add(file.getPath());
				}
			}
		}
		setListAdapter(adapter);
	}

	@Override
	protected void onListItemClick(ListView l, View v, int position, long id) {
		if (!mItemFlag) {
			v.setBackgroundColor(getResources().getColor(R.color.lightyellow));
			mItemFlag = true;
		} else {
			v.setBackgroundColor(getResources().getColor(R.color.white));
			mItemFlag = false;
		}
		File file = new File(paths.get(position));
		if (file != null) {
			if (file.isDirectory()) {
				curPath = paths.get(position);
				getFileDir(paths.get(position));
			} else {
				curPath = paths.get(position);
			}
		}
	}
}