本文主要介绍如何自定义显示手机sd卡当中的文件及文件夹，这样做的好处主要是能够自己定义文件夹和文件的图标样式，而且能够按照应用的需要设计选择的模式（本文介绍的是单选文件）。

第一步：创建ListView的自定义item文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="match_parent"
              android:layout_height="match_parent">
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="50dp">

        //用于显示文件和文件夹的图标
        <ImageView
            android:id="@+id/iv_icon"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:layout_marginLeft="@dimen/interval_common"
            android:layout_centerVertical="true"
            android:src="@mipmap/ic_launcher_round"/>

        //用于显示文件和文件夹的名称
        <TextView
            android:id="@+id/tv_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="@color/colorPrimaryDark"
            android:text="yinxinwdjwwwwwwwwwwwwww"
            android:textSize="20sp"
            android:layout_toRightOf="@+id/iv_icon"
            android:layout_toLeftOf="@+id/iv_check"
            android:layout_marginLeft="@dimen/interval_common"
            android:layout_marginRight="@dimen/interval_common"
            android:layout_centerVertical="true"
            android:ellipsize="middle"
            android:maxLines="1"/>
        
         //用于显示文件被选中的图标，文件夹则不显示这个控件
        <ImageView
            android:id="@+id/iv_check"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:layout_alignParentRight="true"
            android:layout_marginRight="@dimen/interval_common"
            android:layout_centerVertical="true"
            android:src="@mipmap/ic_launcher"/>
    </RelativeLayout>

</LinearLayout>

第二步：构建Adapter，这里采用的是itemview的方式。
Adapter文件

public class FileAdapter extends BaseAdapter {

    private Context context;
    private List<FileInfo> fileList;

    public FileAdapter(Context context, List<FileInfo> fileList) {
        this.context = context;
        this.fileList = fileList;
    }

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

    @Override
    public Object getItem(int position) {
        return fileList.get(position);
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        FileInfo info = fileList.get(position);
        FileItemView itemView;
        if (convertView == null) {
            itemView = new FileItemView(context);
        } else {
            itemView = (FileItemView) convertView;
        }

        itemView.bind(info);
        itemView.setTag(info);
        return itemView;
    }
    
}

FileItemView类

public class FileItemView extends LinearLayout {

    @BindView(R.id.tv_name)
    TextView tvName;
    @BindView(R.id.iv_icon)
    ImageView ivIcon;
    @BindView(R.id.iv_check)
    ImageView ivCheck;

    public FileItemView(Context context) {
        super(context);
        init();
    }

    public FileItemView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public FileItemView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init(){
        inflate(getContext(), R.layout.item_file_adapter, this);
        ButterKnife.bind(this);
    }

    public void bind(FileInfo info){

        tvName.setText(info.getFile().getName());

        if (info.getFile().isDirectory()){
            ivIcon.setImageResource(R.mipmap.ic_launcher_round);
            ivCheck.setVisibility(View.GONE);
        }else {
          /**
           *这里可以根据文件的后缀名，设置对应文件的图标
           **/
            ivIcon.setImageResource(R.mipmap.ic_launcher);
            ivCheck.setVisibility(View.VISIBLE);

            if (info.isCheck()){
                //设置文件选中时的图标
                ivCheck.setImageResource(R.color.colorPrimary);
            }else {
                //设置文件未选中时的图标
                ivCheck.setImageResource(R.color.colorAccent);
            }

        }
    }
}

FileInfo类

public class FileInfo {
    private File file;
    private boolean isCheck;

    public FileInfo(File file) {
        this.file = file;
        this.isCheck = false;
    }

    public File getFile() {
        return file;
    }

    public void setFile(File file) {
        this.file = file;
    }

    public boolean isCheck() {
        return isCheck;
    }

    public void setCheck(boolean check) {
        isCheck = check;
    }
}

注：FileItemView当中的控件ID，采用的是BindView的方式，需要在gradle文件当中添加依赖

compile 'com.jakewharton:butterknife:8.4.0'
annotationProcessor 'com.jakewharton:butterknife-compiler:8.4.0'

第三步：在activity当中使用adapter

activity的layout文件，添加一个ListView控件即可
对应的xml文件

<ListView
        android:id="@+id/lv_phone_file"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"></ListView>

activity文件

public class InputFileActivity extends BaseActivity {
    @BindView(R.id.lv_phone_file)
    ListView lvFile;


    private File currentFile;
    private List<FileInfo> fileList = new ArrayList<>();
    private FileAdapter fileAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_input_file);
        ButterKnife.bind(this);
        init();


    }

    private void init() {
        //初始为sdcard内文件
        currentFile = new File(Environment.getExternalStorageDirectory().getAbsolutePath());

        fileAdapter = new FileAdapter(InputFileActivity.this, fileList);
        lvFile.setAdapter(fileAdapter);
        lvFile.setOnItemClickListener(new LvItemClick());

        refreshFile();
    }


    /**
     * 刷新文件列表
     */
    private void refreshFile() {
        if (fileList != null) {
            fileList.clear();
        }

        File files[] = currentFile.listFiles();
        for (File file : files) {
            fileList.add(new FileInfo(file));
        }

        fileAdapter.notifyDataSetChanged();
    }

    /**
     * 返回上级文件
     */
    private void goBack() {
        File parent = currentFile.getParentFile();
        if (parent == null || (currentFile.getAbsolutePath().equals(Environment.getExternalStorageDirectory().getAbsolutePath()))) {
            InputFileActivity.this.finish();
        } else {
            if (currentFile.isFile()) {
                currentFile = parent.getParentFile();
            } else {
                currentFile = parent;
            }
            refreshFile();
        }
    }


    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            goBack();
            return true;
        } else {
            return super.onKeyDown(keyCode, event);
        }
    }


    /**
     * listview的item单击事件响应
     */
    private class LvItemClick implements AdapterView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            FileInfo fileInfo = (FileInfo) view.getTag();
            if (fileInfo.getFile().isFile()) {
                if (fileInfo.isCheck()) {
                    fileInfo.setCheck(false);
                } else {
                    for (FileInfo info : fileList) {
                        info.setCheck(false);
                    }
                    fileInfo.setCheck(true);
                }
                fileAdapter.notifyDataSetChanged();

            } else {
                currentFile = fileInfo.getFile();
                refreshFile();
            }
        }
    }


}

最后结果如下：

Paste_Image.png