Question

递归搜索外部存储中的txt文件并将它们放在列表视图中。当线程运行时，应该有一个processdialog。它在我的手机（Android 5.1和Android 4.4）上运行良好，但是当我改为6.0时，它工作了一次，之后对话框无法显示。我认为存储路径存在错误（使用Environment.getExternalStorageDirectory（）。toString（）; ）。如果我使用身体记忆作为默认值，我会得到路径＆＃34; / storage / emulated / 0＆＃34;如果我使用外部存储作为默认值，我得到路径＆＃34; /storage.164F-F6FD"。线程也可以工作，但没有文件加载。

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");
        ArrayList<String> mPath = data.getStringArrayListExtra("file");
        for (int i = 0; i < mPath.size(); i++) {
            File pathFile = new File(mPath.get(i));
            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(this);
    mProgressDialog.setCancelable(false);
    mProgressDialog.setMessage("正在搜索书籍，请稍候 ……");

    mExternalStoragePath = Environment.getExternalStorageDirectory().toString();
    Log.i("JianReader", mExternalStoragePath);
    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 12:
                Log.i("JianReader", message.what + "");
                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(final 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.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Intent ii = new Intent(BookListActivity.this, ReadingActivity.class);
                String itemPath = listItems.get(position).get("Path");
                ii.putExtra("mItemPath", itemPath);
                startActivity(ii);
            }
        });
        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();
    }
}

寻求帮助

Answer 1

＆＃34;从Android 6.0（API级别23）开始，用户在应用程序运行时向应用程序授予权限，而不是在安装应用程序时。此方法简化了应用安装过程，因为用户在安装或更新应用时无需授予权限。＆＃34;

将其更改为

private void requestPermission(String permission){
    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
        if (ContextCompat.checkSelfPermission(BookListActivity.this, 
                Manifest.permission.READ_EXTERNAL_STORAGE)
                        != PackageManager.PERMISSION_GRANTED) {

                        ActivityCompat.requestPermissions(BookListActivity.this,
                                new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
                                MY_PERMISSIONS_REQUEST_READ_CONTACTS);

        }
    }
}

感谢第一条评论 https://developer.android.com/training/permissions/requesting.html

无法搜索android 6.0的txt文件

1 个答案: