android文件管理器用法详解

2019-12-12 03:10:57

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来源：转载

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很久没有写东西了，鉴于某某同学文件管理器不会，这里简单介绍一下，同时写一个demon，参考了网上别人写的代码，自己也学习学习，研究研究。

　　首先所谓文件管理器，看起来就是一个列表，列表里面是文件夹或者文件，首先把布局写出来，我想在最上方的左边显示文件的路径，右边显示该路径下的文件个数，其实还是一个遍历文件，然后用列表显示出来的问题。下面是ListView，用来显示文件列表。下面是运行的效果图：

主界面的布局文件如下:

<?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:orientation="vertical" >  <RelativeLayout     android:id="@+id/top"    android:layout_width="match_parent"    android:layout_height="wrap_content">    <TextView       android:id="@+id/path"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:layout_alignParentLeft="true"      android:layout_centerVertical="true"      android:textSize="@*android:dimen/list_item_size"      android:textColor="@android:color/white"/>        <TextView       android:id="@+id/item_count"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:textSize="@*android:dimen/list_item_size"      android:textColor="@android:color/white"      android:layout_alignParentRight="true"      android:layout_centerVertical="true"/>  </RelativeLayout>  <View     android:layout_width="match_parent"    android:layout_height="2dip"    android:background="#09c"/>  <LinearLayout    android:orientation="vertical"    android:layout_width="match_parent"    android:layout_height="match_parent">        <ListView       android:id="@+id/file_list"      android:layout_height="match_parent"      android:layout_width="match_parent"      android:fadingEdge="none"      android:cacheColorHint="@android:color/transparent"/>  </LinearLayout></LinearLayout>

首先在oncreate方法里面调用一个方法去获取布局文件里面的id：

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

initView之后添加apk的权限，777 表示可读可写可操作。

private void initView() {    mListView = (ListView) findViewById(R.id.file_list);    mPathView = (TextView) findViewById(R.id.path);    mItemCount = (TextView) findViewById(R.id.item_count);    mListView.setOnItemClickListener(this);    String apkRoot = "chmod 777 " + getPackageCodePath();     RootCommand(apkRoot);    File folder = new File("/");    initData(folder);  }

修改Root权限的方法：

public static boolean RootCommand (String command) {    Process process = null;    DataOutputStream os = null;    try {      process = Runtime.getRuntime().exec("su");      os = new DataOutputStream(process.getOutputStream());      os.writeBytes(command + "/n");      os.writeBytes("exit/n");      os.flush();      process.waitFor();    }    catch (Exception e) {      return false;    }    finally {      try {        if (os != null) {          os.close();        }        process.destroy();      }      catch (Exception e) {        e.printStackTrace();      }    }    return true;  }

完了之后我们要获取根目录下面的所有的数据，然后设置到我们的ListView中让它显示出来。

private void initData(File folder) {    boolean isRoot = folder.getParent() == null;     mPathView.setText(folder.getAbsolutePath());     ArrayList<File> files = new ArrayList<File>();      if (!isRoot) {      files.add(folder.getParentFile());     }    File[] filterFiles = folder.listFiles();     mItemCount.setText(filterFiles.length + "项");     if (null != filterFiles && filterFiles.length > 0) {      for (File file : filterFiles) {        files.add(file);      }    }    mFileAdpter = new FileListAdapter(this, files, isRoot);     mListView.setAdapter(mFileAdpter);  }

首先是获取当前是否是根目录，然后把文件的路径设置给我们要显示的View。

然后用一个ArrayList来装我们目录下的所有的文件或者文件夹。

首先要把这个文件夹的父类装到我们的列表中去，然后把这个文件夹下的子文件都拿到，也装在列表中，然后调用Adapter显示出来。既然说到了Adapter, 那就看下Adapter吧。

private class FileListAdapter extends BaseAdapter {    private Context context;    private ArrayList<File> files;    private boolean isRoot;    private LayoutInflater mInflater;        public FileListAdapter (Context context, ArrayList<File> files, boolean isRoot) {      this.context = context;      this.files = files;      this.isRoot = isRoot;      mInflater = LayoutInflater.from(context);    }        @Override    public int getCount () {      return files.size();    }    @Override    public Object getItem (int position) {      return files.get(position);    }    @Override    public long getItemId (int position) {      return position;    }        @Override    public View getView (int position, View convertView, ViewGroup parent) {      ViewHolder viewHolder;      if(convertView == null) {        viewHolder = new ViewHolder();        convertView = mInflater.inflate(R.layout.file_list_item, null);        convertView.setTag(viewHolder);        viewHolder.title = (TextView) convertView.findViewById(R.id.file_title);        viewHolder.type = (TextView) convertView.findViewById(R.id.file_type);        viewHolder.data = (TextView) convertView.findViewById(R.id.file_date);        viewHolder.size = (TextView) convertView.findViewById(R.id.file_size);      } else {        viewHolder = (ViewHolder) convertView.getTag();      }            File file = (File) getItem(position);      if(position == 0 && !isRoot) {        viewHolder.title.setText("返回上一级");        viewHolder.data.setVisibility(View.GONE);        viewHolder.size.setVisibility(View.GONE);        viewHolder.type.setVisibility(View.GONE);      } else {        String fileName = file.getName();        viewHolder.title.setText(fileName);        if(file.isDirectory()) {          viewHolder.size.setText("文件夹");          viewHolder.size.setTextColor(Color.RED);          viewHolder.type.setVisibility(View.GONE);          viewHolder.data.setVisibility(View.GONE);        } else {          long fileSize = file.length();          if(fileSize > 1024*1024) {            float size = fileSize /(1024f*1024f);            viewHolder.size.setText(new DecimalFormat("#.00").format(size) + "MB");          } else if(fileSize >= 1024) {            float size = fileSize/1024;            viewHolder.size.setText(new DecimalFormat("#.00").format(size) + "KB");          } else {            viewHolder.size.setText(fileSize + "B");          }          int dot = fileName.indexOf('.');          if(dot > -1 && dot < (fileName.length() -1)) {            viewHolder.type.setText(fileName.substring(dot + 1) + "文件");          }          viewHolder.data.setText(new SimpleDateFormat("yyyy/MM/dd HH:mm").format(file.lastModified()));        }      }      return convertView;    }        class ViewHolder {      private TextView title;      private TextView type;      private TextView data;      private TextView size;    }  }

看下adapter的布局文件：

<?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:orientation="vertical" >  <TextView       android:id="@+id/file_title"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:textSize="25sp"      android:textColor="#fff000"/>  <LinearLayout     android:id="@+id/file_info"    android:layout_width="match_parent"    android:layout_height="wrap_content">    <TextView       android:id="@+id/file_size"      android:layout_width="0dip"      android:layout_height="wrap_content"      android:textColor="#ffffcc"      android:layout_weight="1"      android:textSize="18sp"/>        <TextView       android:id="@+id/file_type"      android:layout_width="0dip"      android:layout_height="wrap_content"      android:textColor="#ffffcc"      android:layout_weight="1"      android:gravity="right"      android:textSize="18sp"/>    <TextView       android:id="@+id/file_date"      android:layout_width="0dip"      android:layout_height="wrap_content"      android:textColor="#ffffff"      android:layout_weight="1"      android:gravity="right"      android:textSize="18sp"/>  </LinearLayout></LinearLayout>

列表的Item项分2行显示，上面一行显示文件名

下面一行分别显示文件大小，文件类型，文件修改时间。

我们可以通过File file = (File) getItem(position);拿到Item项的文件，如果是在第一个并且不再根目录我们就把第一个也就是parentFile显示为：“返回上一级”，下一行的都隐藏掉。

如果不是第一个位置，可以拿到这个文件的一系列信息。

先把String fileName = file.getName();文件名拿到，显示出来。

如果这个文件是一个文件夹，就把文件的大小显示为“文件夹”，类型和修改时间隐藏掉。

如果不是一个文件夹，可以拿到文件的长度long fileSize = file.length();

根据特定的长度显示文件的大小，B， KB， MB， GB等。

然后拿到文件的类型，通过最后一个“.”之后的字符串就是该文件的类型。

通过viewHolder.data.setText(new SimpleDateFormat("yyyy/MM/dd HH:mm").format(file.lastModified())); 设置文件的最近修改时间。

然后可以设置每个Item项的点击事件，如下所示：

@Override  public void onItemClick (AdapterView<?> parent, View view, int position, long id) {    File file = (File) mFileAdpter.getItem(position);    if(!file.canRead()) {      new AlertDialog.Builder(this).setTitle("提示").setMessage("权限不足").setPositiveButton(android.R.string.ok, new OnClickListener() {                @Override        public void onClick (DialogInterface dialog, int which) {                  }      }).show();    } else if(file.isDirectory()) {      initData(file);    } else {      openFile(file);    }  }

如果这个文件不能读，就弹出对话框显示“权限不足”。

如果是一个文件夹，就在调用一次显示所有文件的方法：initData(file);把这个文件夹作为参数传递下去。

如果是一个文件，就可以调用打开文件的方法打开这个文件。

如何打开文件呢？

可以根据不同的文件的后缀名找到不同的文件类型：

可以用一个二维数组把一些常用的文件类型封装起来。如下：

private final String[][] MIME_MapTable = {    // {后缀名， MIME类型}    { ".3gp", "video/3gpp" },     { ".apk", "application/vnd.android.package-archive" },     { ".asf", "video/x-ms-asf" },     { ".avi", "video/x-msvideo" },    { ".bin", "application/octet-stream" },     { ".bmp", "image/bmp" },     { ".c", "text/plain" },     { ".class", "application/octet-stream" },    { ".conf", "text/plain" },     { ".cpp", "text/plain" },     { ".doc", "application/msword" },    { ".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document" },     { ".xls", "application/vnd.ms-excel" },    { ".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" },     { ".exe", "application/octet-stream" },    { ".gif", "image/gif" },     { ".gtar", "application/x-gtar" },     { ".gz", "application/x-gzip" },     { ".h", "text/plain" },     { ".htm", "text/html" },    { ".html", "text/html" },     { ".jar", "application/java-archive" },     { ".java", "text/plain" },     { ".jpeg", "image/jpeg" },    { ".jpg", "image/jpeg" },     { ".js", "application/x-javascript" },     { ".log", "text/plain" },     { ".m3u", "audio/x-mpegurl" },    { ".m4a", "audio/mp4a-latm" },     { ".m4b", "audio/mp4a-latm" },     { ".m4p", "audio/mp4a-latm" },     { ".m4u", "video/vnd.mpegurl" },    { ".m4v", "video/x-m4v" },     { ".mov", "video/quicktime" },     { ".mp2", "audio/x-mpeg" },     { ".mp3", "audio/x-mpeg" },     { ".mp4", "video/mp4" },    { ".mpc", "application/vnd.mpohun.certificate" },     { ".mpe", "video/mpeg" },     { ".mpeg", "video/mpeg" },     { ".mpg", "video/mpeg" },    { ".mpg4", "video/mp4" },     { ".mpga", "audio/mpeg" },     { ".msg", "application/vnd.ms-outlook" },     { ".ogg", "audio/ogg" },    { ".pdf", "application/pdf" },     { ".png", "image/png" },     { ".pps", "application/vnd.ms-powerpoint" },    { ".ppt", "application/vnd.ms-powerpoint" },     { ".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation" },    { ".prop", "text/plain" },     { ".rc", "text/plain" },     { ".rmvb", "audio/x-pn-realaudio" },     { ".rtf", "application/rtf" },    { ".sh", "text/plain" },     { ".tar", "application/x-tar" },     { ".tgz", "application/x-compressed" },     { ".txt", "text/plain" },    { ".wav", "audio/x-wav" },     { ".wma", "audio/x-ms-wma" },     { ".wmv", "audio/x-ms-wmv" },     { ".wps", "application/vnd.ms-works" },    { ".xml", "text/plain" },     { ".z", "application/x-compress" },     { ".zip", "application/x-zip-compressed" },     { "", "*/*" }     };

分别对应的是后缀名和对应的文件类型。

我们可以根据文件的后缀名拿到文件的MIMEType类型：

private String getMIMEType(File file) {    String type = "*/*";    String fileName = file.getName();    int dotIndex = fileName.indexOf('.');    if(dotIndex < 0) {      return type;    }    String end = fileName.substring(dotIndex, fileName.length()).toLowerCase();    if(end == "") {      return type;    }    for(int i=0; i<MIME_MapTable.length; i++) {      if(end == MIME_MapTable[i][0]) {        type = MIME_MapTable[i][1] ;      }    }    return type;  }

先遍历后缀名，如果找到，就把对应的类型找到并返回。

拿到了类型，就可以打开这个文件。

用这个intent.setDataAndType(Uri.fromFile(file), type); 打开设置打开文件的类型。

如果type是*/*会弹出所有的可供选择的应用程序。

到这里一个简易的文件管理器就成型了。

源代码：

package com.android.test;import java.io.DataOutputStream;import java.io.File;import java.text.DecimalFormat;import java.text.SimpleDateFormat;import java.util.ArrayList;import android.app.Activity;import android.app.AlertDialog;import android.content.Context;import android.content.DialogInterface;import android.content.Intent;import android.content.DialogInterface.OnClickListener;import android.graphics.Color;import android.net.Uri;import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.AdapterView;import android.widget.AdapterView.OnItemClickListener;import android.widget.BaseAdapter;import android.widget.ListView;import android.widget.TextView;import android.widget.Toast;public class FileManager extends Activity implements OnItemClickListener {    private ListView mListView;  private TextView mPathView;  private FileListAdapter mFileAdpter;  private TextView mItemCount;    @Override  protected void onCreate (Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.file_manager);    initView();  }    private void initView() {    mListView = (ListView) findViewById(R.id.file_list);    mPathView = (TextView) findViewById(R.id.path);    mItemCount = (TextView) findViewById(R.id.item_count);    mListView.setOnItemClickListener(this);    String apkRoot = "chmod 777 " + getPackageCodePath();     RootCommand(apkRoot);    File folder = new File("/");    initData(folder);  }    public static boolean RootCommand (String command) {    Process process = null;    DataOutputStream os = null;    try {      process = Runtime.getRuntime().exec("su");      os = new DataOutputStream(process.getOutputStream());      os.writeBytes(command + "/n");      os.writeBytes("exit/n");      os.flush();      process.waitFor();    }    catch (Exception e) {      return false;    }    finally {      try {        if (os != null) {          os.close();        }        process.destroy();      }      catch (Exception e) {        e.printStackTrace();      }    }    return true;  }    private void initData(File folder) {    boolean isRoot = folder.getParent() == null;     mPathView.setText(folder.getAbsolutePath());     ArrayList<File> files = new ArrayList<File>();      if (!isRoot) {      files.add(folder.getParentFile());     }    File[] filterFiles = folder.listFiles();     mItemCount.setText(filterFiles.length + "项");     if (null != filterFiles && filterFiles.length > 0) {      for (File file : filterFiles) {        files.add(file);      }    }    mFileAdpter = new FileListAdapter(this, files, isRoot);     mListView.setAdapter(mFileAdpter);  }    private class FileListAdapter extends BaseAdapter {    private Context context;    private ArrayList<File> files;    private boolean isRoot;    private LayoutInflater mInflater;        public FileListAdapter (Context context, ArrayList<File> files, boolean isRoot) {      this.context = context;      this.files = files;      this.isRoot = isRoot;      mInflater = LayoutInflater.from(context);    }        @Override    public int getCount () {      return files.size();    }    @Override    public Object getItem (int position) {      return files.get(position);    }    @Override    public long getItemId (int position) {      return position;    }        @Override    public View getView (int position, View convertView, ViewGroup parent) {      ViewHolder viewHolder;      if(convertView == null) {        viewHolder = new ViewHolder();        convertView = mInflater.inflate(R.layout.file_list_item, null);        convertView.setTag(viewHolder);        viewHolder.title = (TextView) convertView.findViewById(R.id.file_title);        viewHolder.type = (TextView) convertView.findViewById(R.id.file_type);        viewHolder.data = (TextView) convertView.findViewById(R.id.file_date);        viewHolder.size = (TextView) convertView.findViewById(R.id.file_size);      } else {        viewHolder = (ViewHolder) convertView.getTag();      }            File file = (File) getItem(position);      if(position == 0 && !isRoot) {        viewHolder.title.setText("返回上一级");        viewHolder.data.setVisibility(View.GONE);        viewHolder.size.setVisibility(View.GONE);        viewHolder.type.setVisibility(View.GONE);      } else {        String fileName = file.getName();        viewHolder.title.setText(fileName);        if(file.isDirectory()) {          viewHolder.size.setText("文件夹");          viewHolder.size.setTextColor(Color.RED);          viewHolder.type.setVisibility(View.GONE);          viewHolder.data.setVisibility(View.GONE);        } else {          long fileSize = file.length();          if(fileSize > 1024*1024) {            float size = fileSize /(1024f*1024f);            viewHolder.size.setText(new DecimalFormat("#.00").format(size) + "MB");          } else if(fileSize >= 1024) {            float size = fileSize/1024;            viewHolder.size.setText(new DecimalFormat("#.00").format(size) + "KB");          } else {            viewHolder.size.setText(fileSize + "B");          }          int dot = fileName.indexOf('.');          if(dot > -1 && dot < (fileName.length() -1)) {            viewHolder.type.setText(fileName.substring(dot + 1) + "文件");          }          viewHolder.data.setText(new SimpleDateFormat("yyyy/MM/dd HH:mm").format(file.lastModified()));        }      }      return convertView;    }        class ViewHolder {      private TextView title;      private TextView type;      private TextView data;      private TextView size;    }  }  @Override  public void onItemClick (AdapterView<?> parent, View view, int position, long id) {    File file = (File) mFileAdpter.getItem(position);    if(!file.canRead()) {      new AlertDialog.Builder(this).setTitle("提示").setMessage("权限不足").setPositiveButton(android.R.string.ok, new OnClickListener() {                @Override        public void onClick (DialogInterface dialog, int which) {                  }      }).show();    } else if(file.isDirectory()) {      initData(file);    } else {      openFile(file);    }  }    private void openFile(File file) {    Intent intent = new Intent();    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);     intent.setAction(Intent.ACTION_VIEW);     String type = getMIMEType(file);     intent.setDataAndType(Uri.fromFile(file), type);     try {      startActivity(intent);    }    catch (Exception e) {      Toast.makeText(this, "未知类型，不能打开", Toast.LENGTH_SHORT).show();    }  }    private String getMIMEType(File file) {    String type = "*/*";    String fileName = file.getName();    int dotIndex = fileName.indexOf('.');    if(dotIndex < 0) {      return type;    }    String end = fileName.substring(dotIndex, fileName.length()).toLowerCase();    if(end == "") {      return type;    }    for(int i=0; i<MIME_MapTable.length; i++) {      if(end == MIME_MapTable[i][0]) {        type = MIME_MapTable[i][1] ;      }    }    return type;  }    private final String[][] MIME_MapTable = {    // {后缀名， MIME类型}    { ".3gp", "video/3gpp" },     { ".apk", "application/vnd.android.package-archive" },     { ".asf", "video/x-ms-asf" },     { ".avi", "video/x-msvideo" },    { ".bin", "application/octet-stream" },     { ".bmp", "image/bmp" },     { ".c", "text/plain" },     { ".class", "application/octet-stream" },    { ".conf", "text/plain" },     { ".cpp", "text/plain" },     { ".doc", "application/msword" },    { ".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document" },     { ".xls", "application/vnd.ms-excel" },    { ".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" },     { ".exe", "application/octet-stream" },    { ".gif", "image/gif" },     { ".gtar", "application/x-gtar" },     { ".gz", "application/x-gzip" },     { ".h", "text/plain" },     { ".htm", "text/html" },    { ".html", "text/html" },     { ".jar", "application/java-archive" },     { ".java", "text/plain" },     { ".jpeg", "image/jpeg" },    { ".jpg", "image/jpeg" },     { ".js", "application/x-javascript" },     { ".log", "text/plain" },     { ".m3u", "audio/x-mpegurl" },    { ".m4a", "audio/mp4a-latm" },     { ".m4b", "audio/mp4a-latm" },     { ".m4p", "audio/mp4a-latm" },     { ".m4u", "video/vnd.mpegurl" },    { ".m4v", "video/x-m4v" },     { ".mov", "video/quicktime" },     { ".mp2", "audio/x-mpeg" },     { ".mp3", "audio/x-mpeg" },     { ".mp4", "video/mp4" },    { ".mpc", "application/vnd.mpohun.certificate" },     { ".mpe", "video/mpeg" },     { ".mpeg", "video/mpeg" },     { ".mpg", "video/mpeg" },    { ".mpg4", "video/mp4" },     { ".mpga", "audio/mpeg" },     { ".msg", "application/vnd.ms-outlook" },     { ".ogg", "audio/ogg" },    { ".pdf", "application/pdf" },     { ".png", "image/png" },     { ".pps", "application/vnd.ms-powerpoint" },    { ".ppt", "application/vnd.ms-powerpoint" },     { ".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation" },    { ".prop", "text/plain" },     { ".rc", "text/plain" },     { ".rmvb", "audio/x-pn-realaudio" },     { ".rtf", "application/rtf" },    { ".sh", "text/plain" },     { ".tar", "application/x-tar" },     { ".tgz", "application/x-compressed" },     { ".txt", "text/plain" },    { ".wav", "audio/x-wav" },     { ".wma", "audio/x-ms-wma" },     { ".wmv", "audio/x-ms-wmv" },     { ".wps", "application/vnd.ms-works" },    { ".xml", "text/plain" },     { ".z", "application/x-compress" },     { ".zip", "application/x-zip-compressed" },     { "", "*/*" }     };}

最后补充一下，布局文件中的dimension是编译到jar包里面去了的，没有jar包的童鞋可以改成自己定义大小。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持武林网。

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