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 */@Overrideprotected 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();;}}}}@Overrideprotected 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); // MultimListView.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 blocke.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);elseadapter.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>>();}@Overridepublic long getItemId(int position) {return position;}@Overridepublic int getCount() {return listItems.size();}@Overridepublic Object getItem(int i) {return listItems.get(i);}@Overridepublic 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;@Overrideprotected 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);}@Overrideprotected 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);}}}}