android选择文件（安卓系统文件夹详解）

废话没有，先看效果

第一步：创建MainActivity

import android.app.Activity;import android.content.Context;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.TextView;import com.rdsa.singleselectedfileorfolder.R;import java.util.ArrayList;public class MainActivity extends AppCompatActivity {    public Context mContext;    private Button selectFile, selectFolder, mSelectFile, mSelectFolder;    private TextView result;    private Activity activity;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        this.mContext = this;        this.activity = this;        setContentView(R.layout.activity_main);        initView();        initData();        initEvent();    }    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        super.onActivityResult(requestCode, resultCode, data);        if (requestCode == ChooseFileOrDirActivity.RequestCode && resultCode == ChooseFileOrDirActivity.ResultCode) {            ArrayList<String> resPath = data.getStringArrayListExtra(ChooseFileOrDirActivity.ResultData);            StringBuffer sb = new StringBuffer();            for(String item : resPath) {                sb.append(item).append("rn");            }            result.setText(sb.toString());        }    }    private void initView() {        this.result = super.findViewById(R.id.result);        this.selectFile = super.findViewById(R.id.selectFile);        this.selectFolder = super.findViewById(R.id.selectFolder);        this.mSelectFile = super.findViewById(R.id.mSelectFile);        this.mSelectFolder = super.findViewById(R.id.mSelectFolder);    }    private void initData() {    }    private void initEvent() {        selectFile.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                Intent intent = new Intent(activity, ChooseFileOrDirActivity.class);                intent.putExtra(ChooseFileOrDirActivity.EnterVar, ChooseFileOrDirActivity.SingleFile);                activity.startActivityForResult(intent, ChooseFileOrDirActivity.RequestCode);            }        });        selectFolder.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                Intent intent = new Intent(activity, ChooseFileOrDirActivity.class);                intent.putExtra(ChooseFileOrDirActivity.EnterVar, ChooseFileOrDirActivity.SingleFolder);                activity.startActivityForResult(intent, ChooseFileOrDirActivity.RequestCode);            }        });        mSelectFile.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                Intent intent = new Intent(activity, ChooseFileOrDirActivity.class);                intent.putExtra(ChooseFileOrDirActivity.EnterVar, ChooseFileOrDirActivity.MultiFile);                activity.startActivityForResult(intent, ChooseFileOrDirActivity.RequestCode);            }        });        mSelectFolder.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                Intent intent = new Intent(activity, ChooseFileOrDirActivity.class);                intent.putExtra(ChooseFileOrDirActivity.EnterVar, ChooseFileOrDirActivity.MultiFolder);                activity.startActivityForResult(intent, ChooseFileOrDirActivity.RequestCode);            }        });    }}

第二步：创建MainActivity布局文件activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    tools:context="com.rdsa.selectedfileorfolder.MainActivity">    <Button        android:id="@+id/selectFolder"        android:text="文件夹选择(单选)"        android:layout_width="match_parent"        android:layout_height="wrap_content"   />    <Button        android:id="@+id/selectFile"        android:text="文件选择（单选）"        android:layout_width="match_parent"        android:layout_height="wrap_content"   />    <Button        android:id="@+id/mSelectFolder"        android:text="文件夹选择(多选)"        android:layout_width="match_parent"        android:layout_height="wrap_content"   />    <Button        android:id="@+id/mSelectFile"        android:text="文件选择（多选）"        android:layout_width="match_parent"        android:layout_height="wrap_content"   />    <TextView        android:id="@+id/result"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="Wait for Result" /></LinearLayout>

第三步：创建目录数据存储类FileOrDirBeans

public class FileOrDirBeans {    String isFile, name, isCheckVisible, isChecked, absolutePath ;    public FileOrDirBeans(String... params) {        this.isFile = params[0];        this.name = params[1];        this.isCheckVisible = params[2];        this.isChecked = params[3];        this.absolutePath = params[4];    }    public String getIsFile() {        return isFile;    }    public void setIsFile(String isFile) {        this.isFile = isFile;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getIsCheckVisible() {        return isCheckVisible;    }    public void setIsCheckVisible(String isCheckVisible) {        this.isCheckVisible = isCheckVisible;    }    public String getIsChecked() {        return isChecked;    }    public void setIsChecked(String isChecked) {        this.isChecked = isChecked;    }    public String getAbsolutePath() {        return absolutePath;    }    public void setAbsolutePath(String absolutePath) {        this.absolutePath = absolutePath;    }}

第四步：创建文件浏览ChooseFileOrDirActivity

import android.Manifest;import android.app.Activity;import android.content.Intent;import android.content.pm.PackageManager;import android.os.Build;import android.os.Bundle;import android.os.Environment;import android.view.KeyEvent;import android.view.View;import android.widget.Button;import android.widget.ListView;import android.widget.TextView;import com.rdsa.singleselectedfileorfolder.R;import java.io.File;import java.util.ArrayList;import java.util.Arrays;import java.util.Collections;import java.util.Comparator;import java.util.List;public class ChooseFileOrDirActivity extends Activity {    public static final String EnterVar = "EnterVar";    public static final String ResultData = "SELECTED";    public static final int RequestCode = 888;    public static final int ResultCode = 999;    public static final int SingleFile = 1000;    public static final int SingleFolder = 2000;    public static final int MultiFile = 3000;    public static final int MultiFolder = 2001;    private String rootPath = Environment.getExternalStorageDirectory().getAbsolutePath();    private static final int REQUESCODE = 5;    private static final String NEED_PERMISSION = Manifest.permission.WRITE_EXTERNAL_STORAGE;    private ListView listView4File;    private TextView noDataTip;    private Button btChose;    private List<String> data;    private ArrayList<FileOrDirBeans> fileOrDirList;    private FileAdapter fileAdapter;    private int enterVar;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.ly_choose_file_or_folder);        this.enterVar = this.getIntent().getIntExtra(EnterVar, SingleFile);        this.initView();        this.initData();        this.initEvent();    }    private void initData() {        this.listView4File.setEmptyView(noDataTip);        this.data = new ArrayList<>();        this.fileOrDirList = new ArrayList<>();        this.fileAdapter = new FileAdapter(this, fileOrDirList, enterVar);        this.listView4File.setAdapter(fileAdapter);        if (Build.VERSION.SDK_INT >= 23) {      // 判断系统版本是否大于6.0            if (checkSelfPermission(NEED_PERMISSION) == PackageManager.PERMISSION_GRANTED) {  //检查是否有读写权限                loadDataFromPath(rootPath, enterVar);//从路径中加载数据            } else {                requestPermissions(new String[]{NEED_PERMISSION}, REQUESCODE); // 申请权限            }        } else {            loadDataFromPath(rootPath, enterVar);//系统版本小于6.0直接加载数据        }    }    private void loadDataFromPath(final String mPath, final int type) {        this.data.clear();    // data为 ListView 中要显示的数据        this.fileOrDirList.clear();        new Thread() {            public void run() {                super.run();                data = orderByName(mPath, type == SingleFolder || type == MultiFolder);                fileOrDirList = getBeans(data, type);                runOnUiThread(new Runnable() {                    @Override                    public void run() {                        fileAdapter.setData(data, fileOrDirList);//将数据载入适配器当中                    }                });            }        }.start();    }    private ArrayList<FileOrDirBeans> getBeans(List<String> fileList, final int type) {        ArrayList<FileOrDirBeans> resultList = new ArrayList<>();        for(String fileItem : fileList) {            File file = new File(fileItem);            String isFile = String.valueOf(file.isFile());            String isCheckVisible = (file.isFile() || type == SingleFolder || type == MultiFolder) ?  "true" : "false";;            FileOrDirBeans bean = new FileOrDirBeans(isFile, file.getName(), isCheckVisible, "false", fileItem);            resultList.add(bean);        }        return resultList;    }    private void initView() {        listView4File = findViewById(R.id.rvFileView);        noDataTip = findViewById(R.id.noDataTip);    }    private void initEvent() {        fileAdapter.setEvent(new FileAdapter.Event() {            @Override            public void enterNextDir(String path) {                rootPath = path;                loadDataFromPath(rootPath, enterVar);            }        });        findViewById(R.id.btChose).setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                Intent intent = new Intent();                intent.putStringArrayListExtra(ResultData, fileAdapter.getSelectData());                setResult(ResultCode, intent);                finish();            }        });    }    @Override    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {        super.onRequestPermissionsResult(requestCode, permissions, grantResults);        if (requestCode == REQUESCODE && permissions[0].equals(NEED_PERMISSION)) {            loadDataFromPath(rootPath, enterVar);        }    }    @Override    public boolean onKeyDown(int keyCode, KeyEvent event) {        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {//点击的是返回键            if (event.getAction() == KeyEvent.ACTION_DOWN && event.getRepeatCount() == 0) {//按键的按下事件                if (rootPath.trim().equals(Environment.getExternalStorageDirectory().getAbsolutePath())) {                    return super.onKeyDown(keyCode, event);                } else {                    File file = new File(rootPath);                    if (!file.exists()) {                        return super.onKeyDown(keyCode, event);                    }                    rootPath = file.getParent();                    loadDataFromPath(rootPath, enterVar);                    return false;                }            }        }        return super.onKeyDown(keyCode, event);    }    public static ArrayList<String> orderByName(String filePath, boolean excludeFile) {        ArrayList<String> FileNameList = new ArrayList<String>();        File file = new File(filePath);        File[] files = file.listFiles();        List fileList = Arrays.asList(files);        Collections.sort(fileList, new Comparator<File>() {            @Override            public int compare(File o1, File o2) {                if (o1.isDirectory() && o2.isFile())                    return -1;                if (o1.isFile() && o2.isDirectory())                    return 1;                return o1.getName().compareTo(o2.getName());            }        });        for (File itemFile : files) {            if(itemFile.getName().startsWith(".")) {                continue;            } else {                if(itemFile.isFile() && excludeFile) {                    continue;                }                FileNameList.add(itemFile.getAbsolutePath());  //往集合中添加符合条件的数据            }        }        return FileNameList;    }}

第五步：创建ChooseFileOrDirActivity布局文件
ly_choose_file_or_folder.xml

<?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:layout_width="match_parent"        android:layout_height="50dp"        android:background="#F9F9FA">        <TextView            android:id="@+id/tvTitle"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_centerInParent="true" />        <Button            android:id="@+id/btChose"            android:layout_width="wrap_content"            android:layout_height="30dp"            android:layout_alignParentRight="true"            android:layout_centerVertical="true"            android:layout_marginRight="5dp"            android:background="@drawable/bg_button"            android:text="确定"            android:textColor="#458B74" />    </RelativeLayout>    <ListView        android:id="@+id/rvFileView"        android:layout_width="match_parent"        android:layout_height="match_parent" />    <TextView        android:id="@+id/noDataTip"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:gravity="center_vertical|center_horizontal"        android:text="没有数据可用，返回上一层" /></LinearLayout>

第六步：创建ListView的数据容器类FileAdapter

import android.content.Context;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.CheckBox;import android.widget.CompoundButton;import android.widget.ImageView;import android.widget.TextView;import com.rdsa.singleselectedfileorfolder.R;import java.util.ArrayList;import java.util.List;public class FileAdapter extends BaseAdapter {    private Context context;    private Event event;    private ArrayList<String> selectData;    private ArrayList<FileOrDirBeans> fileOrDirList;    private LayoutInflater mLayoutInflater;      //   将 Item 的 XML 转换成 View    private final int enterVar;    public FileAdapter(Context context, final ArrayList<FileOrDirBeans> fileOrDirList, int enterVar) {        this.context = context;        this.selectData = new ArrayList<>();        this.mLayoutInflater = LayoutInflater.from(context);     // context 必须是界面所在的 context        this.enterVar = enterVar;        this.fileOrDirList = fileOrDirList;    }    @Override    public int getCount() {        return this.fileOrDirList.size();    }    @Override     // 数据项    public Object getItem(int position) {        return fileOrDirList.get(position);    }    @Override    public long getItemId(int position) {        return position;    }    @Override    // 显示的内容    public View getView(final int position, View convertView, ViewGroup viewGroup) {        ViewHolder viewHolder;        if(convertView == null) {            convertView = mLayoutInflater.inflate(R.layout.filechoose_layout_fileitme, null);            viewHolder = new ViewHolder();            viewHolder.icon = convertView.findViewById(R.id.icon);            viewHolder.fileName = convertView.findViewById(R.id.fileName);            viewHolder.checkBox = convertView.findViewById(R.id.checkBox);            convertView.setTag(viewHolder);        } else {            viewHolder = (ViewHolder)convertView.getTag();        }        final FileOrDirBeans bean = fileOrDirList.get(position);        final String absPath = bean.getAbsolutePath();        bean.setIsChecked("false");    //   初始化一个boolean值 来判断是否被选中        for (String s : selectData) {    // 遍历选中的集合            if (s.trim().equals(absPath)) {    // 如果集合中的子元素与适配其中的路径相同                bean.setIsChecked("true");     // 判断已被选中                break; //终止循环            }        }        viewHolder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {            @Override            public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {//设置checkBox的点击事件                if (isChecked) {//选中状态                    if (selectData.contains(absPath)) {//如果集合中包含了该元素则直接返回                        if (enterVar == ChooseFileOrDirActivity.SingleFile || enterVar == ChooseFileOrDirActivity.SingleFolder) {                            selectData.clear();                            selectData.add(absPath);                        }                    } else {//否则添加                        if(enterVar == ChooseFileOrDirActivity.SingleFile || enterVar == ChooseFileOrDirActivity.SingleFolder) {                            selectData.clear();                        }                        selectData.add(absPath);                    }                } else {//未选中状态                    if (selectData.contains(absPath)) {//如果集合中包含了该元素则移除                        selectData.remove(absPath);                    } else {//否则 返回                        return;                    }                }                notifyDataSetChanged();            }        });        viewHolder.icon.setImageDrawable(Boolean.parseBoolean(bean.getIsFile()) ?  context.getResources().getDrawable(R.drawable._16_file) : context.getResources().getDrawable(R.drawable._16_folder));        viewHolder.fileName.setText(bean.getName());        viewHolder.checkBox.setVisibility((Boolean.parseBoolean(bean.isCheckVisible))?  View.VISIBLE : View.GONE);        viewHolder.checkBox.setChecked(Boolean.parseBoolean(bean.getIsChecked()));        viewHolder.fileName.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                if(!Boolean.parseBoolean(bean.getIsFile())) {                    event.enterNextDir(fileOrDirList.get(position).getAbsolutePath());                }            }        });        return convertView;    }    static class ViewHolder {        private ImageView icon;        private TextView fileName;        private CheckBox checkBox;    }    public interface Event {        void enterNextDir(String path);//进入下一个文件夹    }    public void setData(List<String> data, ArrayList<FileOrDirBeans> fileOrDirList) {        this.fileOrDirList.clear();        this.fileOrDirList.addAll(fileOrDirList);        notifyDataSetChanged();    }    public void setEvent(Event event) {        this.event = event;    }    public ArrayList<String> getSelectData() {        return selectData;    }}

第七步：创建FileAdapter每一项的布局文件
filechoose_layout_fileitme.xml

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="horizontal" >    <ImageView        android:id="@+id/icon"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginStart="8dp"        android:layout_marginEnd="8dp"        android:layout_alignParentStart="true"        android:layout_centerVertical="true"        android: />    <TextView        android:id="@+id/fileName"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginBottom="8dp"        android:layout_marginTop="8dp"        android:paddingRight="50dp"        android:layout_toRightOf="@+id/icon"        android:layout_centerVertical="true"        android:text="TextView"  />    <CheckBox        android:id="@+id/checkBox"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentEnd="true"        android:layout_centerVertical="true"        android:layout_marginEnd="8dp" /></RelativeLayout>

第八步：AndroidManifest 增加对文件操作的授权

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

第九步：用到的图片资源_16_file.png和_16_folder.png

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